Post by: mcgyver74 on April 18, 2021, 08:15:33 PM
My first real post here at Motobrick, Just became the owner of a 1990 K75s that belonged to my dad for many years, due to health issues he can no longer ride so gave me the bike. Sadly it's been sitting outside for years (Under a cover but still) so I have a fair amount of work to do in order to make it safe again. So yesterday the work began
(http://www.motobrick.com/gallery/3/7328-180421191728-36872450.jpeg)
She is looking a bit rough... Sadly she sat outside for a long time and for a few years without even a cover. She's filthy and does have some body damage that I will need to fix.
(http://www.motobrick.com/gallery/3/7328-180421191728-3687411.jpeg) (http://www.motobrick.com/gallery/3/7328-180421191729-36991102.jpeg)
Man that is a dirty bike
(http://www.motobrick.com/gallery/3/7328-180421191729-3699450.jpeg)
and after airing up the tires, and a bit of wrestling, she's on the trailer. (Appreciate my bud helping here, and letting me use his trailer :) )
(http://www.motobrick.com/gallery/3/7328-180421191730-37011137.jpeg)
Yeah, she's been sitting for a while...
(http://www.motobrick.com/gallery/3/7328-180421191731-37021048.jpeg)
Unfortunately, she succumbed to the K75 tank rot issue (This is actually the 2nd tank that has been on this bike for this same reason), looks like I need to find a used tank :(
(http://www.motobrick.com/gallery/3/7328-180421191731-37021457.jpeg)
Starting to get dirty, got the old dead battery out (She held a whopping 1.1volts LOL) I have a new battery
(http://www.motobrick.com/gallery/3/7328-180421191731-37041549.jpeg)
First issue, the throttle was seized SOLID, I got scared for a few, but then saw that the throttle bodies moved freely, it was just the twist grip that was stuck. Some Gentile heat and twisting with a LOT of penetrating oil and I got the tube off, ugh lots of rust, but nothing some emery cloth can't fix
(http://www.motobrick.com/gallery/3/7328-180421191732-37041578.jpeg)
After getting the bar cleaned up, I cleaned out the tube and used copius amounts of white lithium grease, reassembled and she turns smooth and snaps back properly. (Whew, fixed for a grand total of 1 dollar in sandpaper :) )
(http://www.motobrick.com/gallery/3/7328-180421191733-370688.jpeg)
HOLY hell that's a lot of crap in the belly pan LOL, Since it's been sitting there for years I figured at least let's get some decent oil in there before I try to light her off since I don't know what condition the existing oil is.., So I want and got a 5 gallon jug of Castrol 20W-50. I chose this based on the recommendations of Derek At VGG, since it has "All the Minerals and Dinosaurs the bike will need,, and was the cheapest at Walmart" LOL (It's not staying in there, it's just to run a few heat cycles then I will dump it and put in the good Beltran stuff I bought. ( I figure a flush is in order before I give her the good stuff)
(http://www.motobrick.com/gallery/3/7328-180421191733-3706943.jpeg)
Got the throttle tube all re-assembled, now I am fixing some wiring while I wait for the old oil to drain, sadly the rodents got to it, thankfully it was only like 3 wires that needed to be soldered (Didn't get great pics)
Once that was all done, I popped in a new battery and tried to start the engine. Sadly, in addition to the tank leaking, the fuel pump is also seized solid (I verified power to the pump, she has juice but it's not making any of the usual whirly noises and it's not pushing fuel)
So for now, I need to find a fuel tank and pump.
Will update once I have some parts :)
Post by: The Mighty Gryphon on April 18, 2021, 09:41:14 PM
DSCN3541.JPG (111.82 kB . 768x576 - viewed 1248 times) DSCN3787.JPG (69.03 kB . 768x576 - viewed 1208 times)I would clean out the tank, do some prep and take it to a good welder to have the leaky spots repaired. One of my bikes had the tank repaired and it's still holding up very well.
One of the very good things about restoring these bikes is the plethora of good used parts on eBay. The body parts were made from bulk molding compound, which, while rather heavy responds very well to fairly simple repair techniques.
Post by: stokester on April 19, 2021, 07:29:26 AM
Among many other things you have to do be sure to clean and lube the clutch cable barrel at the lever and ensure your fan spins manually.
Good luck and keep us informed of your progress.
Post by: AtLarge on April 19, 2021, 08:16:17 AM
Post by: mcgyver74 on April 25, 2021, 10:40:39 PM
I pulled apart the old tank to see if I could salvage it at all, Yeah that's a hard NO dawg :(
The rubber bits literally dissolved into goo...
the fuel pump wasn't much better, the fuel sending arm was rusted solid as well.
(http://www.motobrick.com/gallery/3/7328-250421222916-37161156.jpeg)
(http://www.motobrick.com/gallery/3/7328-250421222916-37162079.jpeg)
I had a look in hopes I could maybe clean the rust off and salvage the pump but no go, she is locked solid :(
(http://www.motobrick.com/gallery/3/7328-250421222914-3713412.jpeg)
Was hoping I could get the tank welded, but it's just too far gone, the fuel filter was a solid pile of rust..
(http://www.motobrick.com/gallery/3/7328-250421222917-3717508.jpeg)
In addition, there were bubbles forming on the paint on the TOP of the tank, a quick check with the cheat poker and I realized there isn't much metal left :(
THANKFULLY I was able to source a decent used tank, the cap needs a rebuild but she is solid. and she even came with a fuel pump. THe stickers on the gas cap are about all I could salvage from the old tank :(
(http://www.motobrick.com/gallery/3/7328-250421222917-37191093.jpeg)
However sadly she still won't start, the new pump runs and seems to move fuel, I have spark, and I believe I have compression (Put 5 cc of oil in each cyl to be sure) but no vroom. Seems I am not getting fuel.
Next steps are to test the fuel pressure, I am not convinced that the pump I got (it came with the tank) is actually good, when I run it some fuel seems to squirt out of the top seam of the pump itself (In the tank) so Maybe it's not putting enough pressure to open the injectors??
Next steps are to check the fuel pressure (Need to get a gauge) and pick up a noid light so I can confirm I am getting injector pulse... Hopefully it's just a bad pump and not something more sinister (Like rusted up injectors :( )
Will post more when I learn more :)
Post by: Laitch on April 25, 2021, 11:20:19 PM
. . . when I run it some fuel seems to squirt out of the top seam of the pump itself (In the tank) so Maybe it's not putting enough pressure to open the injectors??Fuel pressure doesn't open the injectors; they're opened electronically. Cleaning all electrical connectors and ground connections asap with DeoxIT D5 is recommended.
Autozone, NAPA, or another of the large auto parts chains will loan you a pressure tester—or many other types of tools—if you use a credit card to make a refundable security deposit.
Post by: The Mighty Gryphon on April 26, 2021, 10:20:35 AM
Post by: mcgyver74 on April 26, 2021, 10:22:57 AM
Post by: The Mighty Gryphon on April 26, 2021, 10:27:23 AM
And don't forget the rail. Vinegar is your friend there. You might want to toss the fuel level float in with the rail, just for chuckles.
Post by: mcgyver74 on April 26, 2021, 10:32:46 AM
I will get new O rings and I plan to replace the fuel filter, thankfully I didn't try to use the rusty crusty tank, I bought a good used tank instead with new filter :)
Post by: The Mighty Gryphon on April 26, 2021, 11:13:31 AM
After the soak, blow some spray cleaner through them with one of these kits:
https://www.ebay.com/itm/352819192943?hash=item5225a9a46f:g:Gq4AAOSwsgtfplAY
Instead of a battery, I hooked my injectors up to an old Lionel train transformer, a doorbell transformer will also work. The transformer is nice because it cycles the injector 60 times a second while you spray the cleaner through it. Pull the filter screen out of the injector before you do the spray, but after you clean the exterior of the injector.
Soak the rail in vinegar for a couple days, flush it well and blow it out with compressed air. Any crap in it will wind up in the injectors if you don't do a good job cleaning it.
Post by: mcgyver74 on April 26, 2021, 11:43:02 AM
Post by: The Mighty Gryphon on April 26, 2021, 11:52:28 AM
Post by: stokester on April 26, 2021, 05:49:58 PM
https://www.mrinjector.us/ (https://www.mrinjector.us/)
Post by: mcgyver74 on April 26, 2021, 09:43:02 PM
Post by: Laitch on April 27, 2021, 05:27:55 PM
I got a deal on refurbished injectors from beemer boneyard, figured even if I clean them they are 30 years old :)They could be thirty-year-old injectors that have been refurbished. icon_cheers
Post by: mcgyver74 on May 01, 2021, 10:32:06 PM
Finally installed the new Fuel pump (Don't have pics of that) and the new fuel lines and filter
Next thing to tackle was the breather hose that always fails, and mine was no different, Man that is roached
(http://www.motobrick.com/gallery/3/7328-010521221449-3722544.jpeg)
(http://www.motobrick.com/gallery/3/7328-010521221451-3729161.jpeg)
Shiny new one installed
(http://www.motobrick.com/gallery/3/7328-010521221451-3729368.jpeg)
At this point, the new pump is in, the lines and breather are in, so I tried to fire it up again. No dice. Confirmed I have compression and spark so guess what is lacking is fuel. Time to change the 30 year old Injectors :)
The first one came out pretty hard.. Had to use a pick to get the cap and O ring out :( and the O rings were hard as a rock :(
(http://www.motobrick.com/gallery/3/7328-010521221450-37272177.jpeg)
After a bit of a fight, I got all 3 out :)
(http://www.motobrick.com/gallery/3/7328-010521221449-37222027.jpeg)
Next was to blow out the fuel rail, luckily it was pretty clean inside..
(http://www.motobrick.com/gallery/3/7328-010521221450-37251943.jpeg)
Test fitting all 3 new injectors, (Before I realized it was easier to put them on the fuel rail before installing LOL)
(http://www.motobrick.com/gallery/3/7328-010521221449-37252054.jpeg)
(http://www.motobrick.com/gallery/3/7328-010521221450-372713.jpeg)
Finally buttoned it up and SHE RUNS!!! (Not sure how to post a video so sorry for the youtube link)
https://www.youtube.com/watch?v=qdp47C-f7dk (https://www.youtube.com/watch?v=qdp47C-f7dk)
Still hesitates off idle, not sure what that's about. but now that I know she runs I can order the brake parts I need.. Stay tuned for the next installment :)
Post by: The Mighty Gryphon on May 01, 2021, 11:17:06 PM
About the hesitation, I have noticed that for some reason(I suspect it may be the inertia in the air flow flapper causing a momentarily lean mixture) my K75 engines like to have the throttle rolled on as opposed snapped open. This temporary lean mixture was the reason for the accelerator pump on carburetors. Unfortunately, the early Jetronic systems weren't able to instantaneously enrich the mixture when the throttle is quickly opened.
Throttle response off of idle seems to be better on the K100's and the Motronic engines. I think the extra cylinder also helps overcome the inertia of the crankshaft as well as yanking the air flow flapper open quicker.
Post by: TriSpark on May 04, 2021, 06:52:44 PM
Post by: natalena on May 12, 2021, 12:06:08 AM
Post by: frankenduck on May 12, 2021, 12:31:53 AM
Still hesitates off idle, not sure what that's about. but now that I know she runs I can order the brake parts I need.. Stay tuned for the next installment :)
I set the idle at 1150-1200ish on my K75s so that there's less hesitation when starting from a dead stop.
Post by: mcgyver74 on June 07, 2021, 09:53:56 AM
This weekend was a slow weekend, due to the heat, it was difficult to get a lot done but I did manage to replace all the front brake lines and flush some nice new brake fluid into the system.
Replaced all 3 front brake hoses with a kit from Speigler. The job is not too bad but make sure you use a line wrench and not a regular wrench.
Once all 3 lines were replaced I bled the brakes, and this is where some oddness occurred... Was wondering if y'all encountered this before..
My process was as follows:
- Sucked out the old cruddy fluid from the MC with a vac pump
- Removed and reinstalled all 3 brake lines
- Cleaned MC reservoir out with a towel to get most of the nasty out
- Filled Res with new clean fluid
- Cracked both bleeders and let it gravity bleed for a bit until new fluid was dribbling out of the bleeders
- Closed left bleeder, put vac pump on right bleeder and pulled fluid through until no bubbles were seen
- Closed Right bleeder and repeated this process on left side
The VERY odd part was I had NO brake handle at all, I pulled almost a quart of fresh clean brake fluid through and had NO brake at all..(Yes the handle seemed fine prior to the work) No air bubbles were present but it just would not firm up (had ZERO feel).
I finally got frustrated and needed some cold drinks, so I put the res cap back on and went to lunch, when I got back the handle felt normal again :johnny it literally went from nothing at all to normal feel on it's own. this is making me VERY nervous...
Anybody ever see this before?
Sorry for the photos, it was hot as hell in the garage and I wasn't taking as many photos...
(http://www.motobrick.com/gallery/3/7328-070621094806-3765982.jpeg)
(http://www.motobrick.com/gallery/3/7328-070621094805-3765767.jpeg)
(http://www.motobrick.com/gallery/3/7328-070621094805-37641354.jpeg)
(http://www.motobrick.com/gallery/3/7328-070621094804-37572471.jpeg)
(http://www.motobrick.com/gallery/3/7328-070621094804-37572396.jpeg)
Next week I plan to tackle the following (Time and heat dependent)
- Rear brake lines
- Intake Manifolds and air boots
- Gas Cap rebuild
Post by: frankenduck on June 07, 2021, 10:12:49 AM
When refilling the brake lines:
Turn the handlebars to full lock left.
SLOWLY squeeze the brake lever repeatedly while topping off the master cylinder reservoir as needed. You will see tiny air bubbles coming up as you do this. When the air bubbles stop you've gotten all of the air out of the lines.
Then bleed off any remaining air bubbles down at the calipers.
Remember to pump the lever a few times before going for a test ride.
Post by: Laitch on June 07, 2021, 10:25:40 AM
. . . it literally went from nothing at all to normal feel on it's own. this is making me VERY nervous...Yes. Pressure can be lost when a closed system is opened.
Anybody ever see this before?
My most fun example is when I was conveying myself in a '92 Honda 4x4 station wagon loaded with chainsaws, peaveys, log tongs and other esoteric material to help some friends whose home was covered in downed trees and debris in Miami three days after Hurricane Andrew. I was on the Cross-Bronx Expressway on the Friday of Memorial Day weekend in traffic that was alternating between 50mph and Omph when my brake pedal went to the floor. I hauled up on the emergency brake between the seats then used it to brake and shift with one hand, and steer with the other hand for a few exciting miles, crossing the GW Bridge and final exiting in a New Jersey rest stop. I left the vehicle and had a cup of coffee and a piece of pie in the restaurant while I considered my options.
My option was to find help on a holiday weekend in the Capital Region of Grift or do something else. I decided I'd make it to Miami using the hand brake and get there one way or the other. After I finished eating, I went to the car, opened the hood and there was the master brake cylinder's cap just resting on the threads of its reservoir. I bought some fluid to top up the level, screwed on the cap tightly, started the engine, took a deep breath then stepped on the peddle. It went down about halfway and came up to normal when I pressed it again.
The brakes worked well for years after that; it was the body rust from highway snow removal that wrecked the car.
Post by: mcgyver74 on June 07, 2021, 10:30:56 AM
"Gravity bleeding" (whatever the heck that is) does not do anything to get air out of the system.
Yeah, that does not get rid of the air totally, but it actually does speed up the bleeding process, it lets fluid make its way down the lines so that when you do a normal bleeding procedure it 's a lot less air to pull out.
I've bled brakes using the pump method before, works well, but I switched to a vacuum pump method years ago since I am lazy :)
Post by: frankenduck on June 07, 2021, 11:00:52 AM
Yeah, that does not get rid of the air totally, but it actually does speed up the bleeding process, it lets fluid make its way down the lines so that when you do a normal bleeding procedure it 's a lot less air to pull out.
You're just wasting brake fluid. The air gets out of the system by bubbling out at the top, not by being pulled or pushed downward. (Brake fluid is a liquid that weighs more than air.)
Post by: The Mighty Gryphon on June 07, 2021, 05:59:47 PM
Post by: mcgyver74 on July 03, 2021, 10:29:59 PM
Today was all about tackling the fuel system. The intake manifolds and throttle body boots were dry rotted to heck and back (and It helped me do some more cleaning, wow this thing is filthy)
So first I popped the clamps and removed the throttle body and box...
(http://www.motobrick.com/gallery/3/7328-030721221232-3793849.jpeg)
Sheesh that's a dirty birdy.. Need to protect those throttle bodies and get some cleaning done
(http://www.motobrick.com/gallery/3/7328-030721221234-3794418.jpeg)
This is the main reason I am doing this.. The bike has been acting like it's lean (Stumbling off idle, had a hell of a stutter when revving) and the intake boots were dry rotted and cracked to hell. The intake manifolds weren't cracked (Not shown) but they were hard as a rock..
(http://www.motobrick.com/gallery/3/7328-030721221103-37671378.jpeg)
Let's clean some parts, I am reusing these clamps but not like this LOL
(http://www.motobrick.com/gallery/3/7328-030721221103-3767557.jpeg)
Ah that's better
(http://www.motobrick.com/gallery/3/7328-030721221107-37832468.jpeg)
Ugh even the airbox is grotty.. :(
(http://www.motobrick.com/gallery/3/7328-030721221156-37892357.jpeg)
Ok let's clean up the mating surfaces and get the intake manifolds on
(http://www.motobrick.com/gallery/3/7328-030721221126-3784896.jpeg)
2 out of 3 done (I didn't get an after pic...sorry LOL)
(http://www.motobrick.com/gallery/3/7328-030721221127-37851953.jpeg)
Brandy new parts :)
(http://www.motobrick.com/gallery/3/7328-030721221130-37861297.jpeg)
Ok the throttle bodies need some love too
(http://www.motobrick.com/gallery/3/7328-030721221145-3787196.jpeg)
All back together :)
(http://www.motobrick.com/gallery/3/7328-030721221148-37881729.jpeg)
(http://www.motobrick.com/gallery/3/7328-030721221205-37901239.jpeg)
Even though I will have to pull it off when I install all the new bodywork I got, this windscreen has been bugging me for AGES, it's cracked and crazed. New one is on
(http://www.motobrick.com/gallery/3/7328-030721221216-37911592.jpeg)
Looking sharp!
(http://www.motobrick.com/gallery/3/7328-030721221231-3792163.jpeg)
So she is all back together and it doesn't sputter anymore, I also replaced the hose going from the TB to the fuel pressure regulator because while it was still sealed, it's starting to turn to goo....Used some fuel hose for that instead of the BMW part with the spring... so all done for today... except i need to pull the airbox off again because I am a bonehead 177381, Something is wedged in the wrong place and I cannot open the throttle more then an inch...(Both at the grip and at the TB) Need to see what's hanging it up.... but I can get it to go from idle to 1500 and it's nice and schmooth!!
Of course while warning up, she decided to spring a coolant leak from the lower rad hose, but as those hoses are all 30 years old I cannot be too upset, next to order all new hoses. More to come!! :)
Post by: The Mighty Gryphon on July 04, 2021, 09:52:16 AM
Post by: mcgyver74 on July 04, 2021, 11:53:19 AM
I assume I can just seal the plastic box on top of the throttle bodies and i don't actually need to pull those clamps again?
Post by: John Lang on July 05, 2021, 07:22:25 AM
Post by: Laitch on July 05, 2021, 07:46:26 AM
I assume I can just seal the plastic box on top of the throttle bodies and i don't actually need to pull those clamps again?Sure thing. What shouldn't be done is wash this thing with high pressure if electrical components or connectors are present because water is likely to penetrate them and cause trouble later on.
Post by: mcgyver74 on July 06, 2021, 08:31:49 PM
Post by: TommyT on July 07, 2021, 04:34:28 PM
A young feller offered to clean up my nearly opaque windshield. I accepted with little confidence the 34-year-old plastic could be redeemed. He proved me wrong.Do you know how he did it? I have windshield like yours before cleaning, I was wondering if the car headlight cleaning up kits would work on the BMW windshields.
Post by: mw074 on July 07, 2021, 05:08:39 PM
Post by: John Lang on July 07, 2021, 09:20:41 PM
Post by: mcgyver74 on July 07, 2021, 09:24:15 PM
But something like this should work
(http://www.motobrick.com/gallery/3/7328-070721212358-37951222.jpeg)
Post by: The Mighty Gryphon on July 07, 2021, 11:21:26 PM
If a windshield has been cleaned with Windex or some other cleaner with ammonia there is micro crazing that goes into the plastic deeper than polishing compounds can reach. I've had two windshields with this problem, and they were impossible to correct. You can make them a little better, but they will never look good.
Post by: John Lang on July 08, 2021, 06:43:01 PM
"The process steps and products I used for your bike windshield are listed below in order.
Step 1) clean surface with 50/50 water and isopropyl alcohol
Step 2) wet sanding (3M sandpaper)
- 800 grit
- 1200 grit
- 1500 grit
- 2000 grit
Step 3) Cutting and polishing stage
Product (Chemical Guys V Line for cutting, polishing and removing scratches
- compound cutting with cutting pad
- polishing compound with polishing pad
- finishing compound with finishing pad
Step 4) Clear coat stage:
- applied Meguairs Plastix clear coat and let dry or 1-2 hrs"
Post by: frankenduck on July 08, 2021, 09:53:05 PM
Step 4) Clear coat stage:
- applied Meguairs Plastix clear coat and let dry or 1-2 hrs"
PlastX does not "clear coat" anything. It's a cleaner and polisher. Once you wipe it off it is gone. Nothing is left behind.
And it says right on the bottle that it should be used on small areas at a time and wiped off before it dries.
Post by: TommyT on July 09, 2021, 10:13:51 AM
Reply from the gentleman who cleaned up my windshield. He uses the same process and products for headlight covers.
"The process steps and products I used for your bike windshield are listed below in order.
Step 1) clean surface with 50/50 water and isopropyl alcohol
Step 2) wet sanding (3M sandpaper)
- 800 grit
- 1200 grit
- 1500 grit
- 2000 grit
Step 3) Cutting and polishing stage
Product (Chemical Guys V Line for cutting, polishing and removing scratches
- compound cutting with cutting pad
- polishing compound with polishing pad
- finishing compound with finishing pad
Step 4) Clear coat stage:
- applied Meguairs Plastix clear coat and let dry or 1-2 hrs"
Thanks. I have the 3M kit and did my car headlight covers successfully. Since I plenty of the polish and pads left I will try it first on a small section my K bike.
Post by: stokester on July 09, 2021, 08:11:07 PM
It included compounds and materials for wet sanding to remove the discolored outer layer leaving a hazy surface. A spray with the final coating and use of a UV lamp or parked outside on a sunny day for curing cleared it up nicely. Rather pricey for the kit and labor.
I used one of the commercial kits on my daughter's car which cleaned it up but did not last. I think this was because there was no clear-coat to finish the treatment. Ended up buying some aftermarket.
Post by: frankenduck on July 09, 2021, 11:19:13 PM
Post by: mcgyver74 on July 19, 2021, 12:39:31 PM
Had some weirdness when I started her up, it was only running on 2 cylinders (confirmed this with a power balance test) Odd thing is I could not find a reason, I pulled the coils and cleaned the terminals (and grounds), no change. THen I swapped the plugs from number 3 to number 2 and visa versa and then for some reason all 3 holes started working... Guess I will look into a set of wires.
One odd thing, the bike is smooth from 1k upwards, but if I go to roll on the throttle, there is a hesitation coming off idle, I seem to recall the bike always had that, but it doesn't seem right to me. Any suggestions where to check? :) other then that I ran her for a good while until I confirmed the Rad fan works
Next up is the cooling system, I finally have all new parts so I can refresh that, hoping to tackle it next weekend, can anyone point me to where the bleeder screw for the cooling system is? Also is there a trick to getting that hose that runs through the crankcase out?
TIA!!!
Post by: Laitch on July 19, 2021, 01:09:56 PM
. . . I go to roll on the throttle, there is a hesitation coming off idle, I seem to recall the bike always had that, but it doesn't seem right to me. Any suggestions where to check? :)I don't accept TIA; only TATF is accepted. :laughing4-giggles:
can anyone point me to where the bleeder screw for the cooling system is? Also is there a trick to getting that hose that runs through the crankcase out?
First, I'll let a revered graybeard explain the hesitation, here (http://www.motobrick.com/index.php?topic=9565.msg79824#msg79824).
Next, There is no bleeder screw. What would be your goal if you found one? If you're trying to drain the cooling system remove the radiator filler cap, then either remove the drain plug at the bottom of the combo pump, or remove the coolant hose from the top of the combo pump. If you believe you have air bubles in the system, there's a procedure for dealing with that.
To remove the hose, warm up the hose, soap it, fold it if you're able then slide it out.
Post by: mcgyver74 on July 19, 2021, 01:15:22 PM
My plan was to pop the lower rad hose to drain it, then remove all the hoses so I can get to the thermostat housing, change that then re-assemble and fill. I've had other bikes that had a location where you could bleed the air out (mostly) when doing a coolant change... :)
Post by: Laitch on July 19, 2021, 01:22:20 PM
I've had other bikes that had a location where you could bleed the air out (mostly) when doing a coolant change... :)Mamy of us are familiar with those but you're in Brick territory now. Instructions for filling with coolant and removing air are in the 2V service manual in the Service Manual section of the Technical Directory on the Homepage.
Post by: frankenduck on July 19, 2021, 01:31:49 PM
My plan was to pop the lower rad hose to drain it, then remove all the hoses so I can get to the thermostat housing, change that then re-assemble and fill. I've had other bikes that had a location where you could bleed the air out (mostly) when doing a coolant change... :)
There's no need to do that. The radiator cap "blows" at 1.0 bar when it overheats. When the system is cooling down the radiator cap opens in the other direction at -0.1 bar to draw in coolant from the coolant reservoir. That's why the coolant reservoir exists.
Post by: mcgyver74 on July 19, 2021, 01:35:31 PM
As for the bleeding, it says to crank the starter while burping the lower hose. Wasn't sure if there was more :)
Post by: frankenduck on July 19, 2021, 01:39:39 PM
One odd thing, the bike is smooth from 1k upwards, but if I go to roll on the throttle, there is a hesitation coming off idle, I seem to recall the bike always had that, but it doesn't seem right to me.
Set the idle at 1100+ and most of the hesitation goes away. That's how I have all of my K75s set up.
Post by: Laitch on July 19, 2021, 01:45:57 PM
My plan was . . .If you understand the meaning of burping as it relates to this task, you should be ok. Don't overthink.
Post by: mcgyver74 on July 19, 2021, 01:48:36 PM
If you understand the meaning of burping as it relates to this task, you should be ok. Don't overthink.
Gotcha, (First time on a German bike doing this, on some Jap bikes it's a total PITA :) )