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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: MEZ on July 05, 2014, 11:57:40 AM
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Hello there,
I have chosen the K75 engine for a special build with a RTW trip in mind. The bizarre thing is I know precious little about the engine with regard to riding and maintenance issues. What I would like to ask you all is, what pending issues lie ahead and what precautionary measures would be good to put in place as an OTT step...???
Also I have read all the 'mega squirt' fuel injection posts with interest but do not want to head down that road (way too complex and intricate for me, intensive stuff Mr Author...!!!! ) however......!!! I am building a bespoke fuel supply system to suit the new custom built tank and would appreciate any tips or advise on how to optimise economy & efficiency whilst negotiating all the different conditions that climates have to offer..!! (I know the fuel brain/computer generally takes care of things but there are always further techno gadgets or info to hand..!! ). There is a plug in loop for higher altitudes, anyone have one they will never use and flog it on..????
Cheers in advance MEZ.
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It's a solid engine, the whole drivetrain really. Make sure you keep your splines lubed, though. obviously you'll do a full spline lube before you go, you'll probably only have to do the rear splines along the way, with the newer (post 89 I think) transmissions, they have a hardened input shaft which is good for 40-50k miles between lubes. And longer if all those miles are in a short period of time.
Don't do megasquirt. It won't really help you, the L-Jet is really reliable. My purpose of doing that is to have something to tinker with, though thus far it's been very reliable, and hasn't left me stranded in the 5000 miles or so I've used it for. If you're interested in how L-Jet works, http://demo.cs.brandeis.edu/postscript.dump/Ltronic/Injection.html (http://demo.cs.brandeis.edu/postscript.dump/Ltronic/Injection.html)
The altitude comp loop is just a wire. You can add a dash switch that goes into it. Altitude compensation with fuel injection is much different than with carbs, and is much less of an issue. The plug is theoretically for over 5000 feet. I think it leans the engine slightly. I've had my K75 with the stock injection system to 14,000 feet (Mt. Evans, CO), it did fine, though it was obviously down on power: 14,000 feet is about half of the available air. I had to run it with the "Choke" lever (not really a choke, just a fast idle cam) near the second click to keep the RPM at 1100, the first click didn't have enough throttle to keep it idling. If you were doing an extended trip to those altitudes, you would just have to adjust the idle speed screw.
As to the fuel system, all you need is a standard high pressure fuel pump going to one end of the fuel rail, A hose to the Fuel pressure regulator from the other end of the fuel rail, and a return line going from the fuel pressure regulator. The fuel pressure regulator can be replaced with a more standard unit if need be: it is just a 35psi, manifold pressure compensated one.
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... what precautionary measures would be good to put in place as an OTT step...???
Put your valves in spec and have your injectors cleaned before leaving.
I would suggest having backup electronics either in your tragkorbs or ready-to-ship back at home. Bring spare clutch and throttle cables with you. Spare bulbs and relays onboard too.
Leaving home with new master cylinders and a shock installed wouldn't hurt either.
Where are you located?
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Hello Gents, thanks for replying, I knew this site would be beneficial...!!!
I have the fuel supply system nailed to the last goodridge fitting and am very confident in its working ability and robustness.
Tim, are you saying wipp the head off and do a full valve job, usual decoke, reseat the valves and fit new guide seals..???
All bulbs will be LED including some very OTT offroad LED head lights. Spare relays, noted... I have a spare fuelling brain so that will sit there pre-wrapped minus an address like you say.. The rear shock has been replaced anyway with an upgraded and progressive Alf Hagon +remote damping. I am converting the clutch to hydraulic using a Magura conversion kit by Venhill Racing and GS12 handle bars and switchgear+ levers etc....
What about the clutch guy's...??? Thinking belt and braces should I strip and spec it up...??? I've just bought a 1990 engine (that's three I have now...!!!!) to use as the project item, this has the later 20 spline shaft and as you said a hardened finnish (this I didn't know, thanks) so should be good to go....
WMAX.... So the altitude loop will work with a N/O switch then, no resistance involved at all....????
Thankyou Gents, Mez
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... what precautionary measures would be good to put in place as an OTT step...???
Put your valves in spec and have your injectors cleaned before leaving.
I would suggest having backup electronics either in your tragkorbs or ready-to-ship back at home. Bring spare clutch and throttle cables with you. Spare bulbs and relays onboard too.
Leaving home with new master cylinders and a shock installed wouldn't hurt either.
Where are you located?
Forgot to mention Tim, located in UK, bike being built in Tyne & Wear, Up Norrff....!!!
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Hi Mez, were you ever a Viking or a Poacher? It's just that I used to know a Mez who was!
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Tim, are you saying wipp the head off and do a full valve job,
No. Just check the clearances and replace shims if necessary.
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Hi Mez, were you ever a Viking or a Poacher? It's just that I used to know a Mez who was!
hahaha.......!!!! NO sorry, surname indicates half Germanic half Roman...!! I'm originally a Midlands lad, lived and still do in cornwall for last 25 years but residing in the north for work reasons...!!!
Tim...... noted cheers
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No problems chap :-)
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All the rubber bits....hoses, water and gas,.....intake bushings...vacuum, etc.
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All the rubber bits....hoses, water and gas,.....intake bushings...vacuum, etc.
Noted thanks...... It aint hapnin but would be great if silicon replacement water hoses were aavailable...!!!!
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Noted thanks...... It aint hapnin but would be great if silicon replacement water hoses were aavailable...!!!!
K75 high temp silicone coolant system hoses (http://www.ebay.ca/itm/85-94-86-87-88-89-90-91-92-93-BMW-K75-K-75-SILICONE-RADIATOR-COOLANT-red-HOSE-/380940628366?pt=Motorcycles_Parts_Accessories&hash=item58b1d4b18e&vxp=mtr&_uhb=1)
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Noted thanks...... It aint hapnin but would be great if silicon replacement water hoses were aavailable...!!!!
K75 high temp silicone coolant system hoses (http://www.ebay.ca/itm/85-94-86-87-88-89-90-91-92-93-BMW-K75-K-75-SILICONE-RADIATOR-COOLANT-red-HOSE-/380940628366?pt=Motorcycles_Parts_Accessories&hash=item58b1d4b18e&vxp=mtr&_uhb=1)
...."Completely Brilliant"....!!! Thankyou very much, hmmm.....blue or red...???!!!!!!
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K75 high temp silicone coolant system hoses (http://www.ebay.ca/itm/85-94-86-87-88-89-90-91-92-93-BMW-K75-K-75-SILICONE-RADIATOR-COOLANT-red-HOSE-/380940628366?pt=Motorcycles_Parts_Accessories&hash=item58b1d4b18e&vxp=mtr&_uhb=1)
Are these an improvement over the OEM hoses?
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K75 high temp silicone coolant system hoses (http://www.ebay.ca/itm/85-94-86-87-88-89-90-91-92-93-BMW-K75-K-75-SILICONE-RADIATOR-COOLANT-red-HOSE-/380940628366?pt=Motorcycles_Parts_Accessories&hash=item58b1d4b18e&vxp=mtr&_uhb=1)
Are these an improvement over the OEM hoses?
I wouldn't think so. They're chinese aftermarket. The BMW ones last 30 years. I'd replace them with a set of new oem ones.
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K75 high temp silicone coolant system hoses (http://www.ebay.ca/itm/85-94-86-87-88-89-90-91-92-93-BMW-K75-K-75-SILICONE-RADIATOR-COOLANT-red-HOSE-/380940628366?pt=Motorcycles_Parts_Accessories&hash=item58b1d4b18e&vxp=mtr&_uhb=1)
Are these an improvement over the OEM hoses?
I think your probably right there, defo Chinese origin, new BM one's would be best...
I wouldn't think so. They're chinese aftermarket. The BMW ones last 30 years. I'd replace them with a set of new oem ones.
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Not to mention the Sharpie colors ...
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Here's one Brickers, I have to recite the radiator top up pod that's close to the rad, it will sit on the bracketed forward of the headstock that will hold the clocks & screen etc, my question is simple ..... Does the height matter ?? IE: obviously can't be lower but can it sit a tad higher...??!!!
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Here's one Brickers, I have to recite the radiator top up pod that's close to the rad, it will sit on the bracketed forward of the headstock that will hold the clocks & screen etc, my question is simple ..... Does the height matter ?? IE: obviously can't be lower but can it sit a tad higher...??!!!
It should be fine wherever, so long as it's above the top of the radiator. It's just a burp valve.
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Thanks Wmax... :2thumbup:
Look at this little chap just dropped through the mail box...!!!
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Thanks Wmax... :2thumbup:
Look at this little chap just dropped through the mail box...!!!
Looks Solid. Make sure that's a genuine one, those seem like they get copied a lot.
Another option is to find a compatible regulator for some very common car. I believe the one for VW super beetles and Transporters, which have the same fuel injection system, will work. the goal being the universal availability of the replacement.
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Wmax, I hope it is genuine cus I now need a oil tanker load of 'stem cells' to replace the limbs that it cost...!!!!
Another query, (you have to love this site) I need to know the travel length that the clutch cable moves when lever is moved, ie: from rest to full actuation, or to put it another way, the movement of the rocker arm during this action at the point the nipple sits in..? Make sense..?? This is to gauge the spec of the hydraulic ram I will need for the conversion. I don't have the bike set up just in it's raw build stage....
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Wmax, I hope it is genuine cus I now need a oil tanker load of 'stem cells' to replace the limbs that it cost...!!!!
Another query, (you have to love this site) I need to know the travel length that the clutch cable moves when lever is moved, ie: from rest to full actuation, or to put it another way, the movement of the rocker arm during this action at the point the nipple sits in..? Make sense..?? This is to gauge the spec of the hydraulic ram I will need for the conversion. I don't have the bike set up just in it's raw build stage....
Lol, then it probably is, especially if you got it from a recognized seller.
With the clutch, you should just leave it as a cable. It's more reliable. Custom parts are hard to get in the middle of nowhere. You can easily carry a spare cable as well.
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Wmax, I hope it is genuine cus I now need a oil tanker load of 'stem cells' to replace the limbs that it cost...!!!!
Another query, (you have to love this site) I need to know the travel length that the clutch cable moves when lever is moved, ie: from rest to full actuation, or to put it another way, the movement of the rocker arm during this action at the point the nipple sits in..? Make sense..?? This is to gauge the spec of the hydraulic ram I will need for the conversion. I don't have the bike set up just in it's raw build stage....
I know what you say is true but im running GS1200 gear and want to go with the hydraulic clutch, sorry...!!! I'll sort it.....
Lol, then it probably is, especially if you got it from a recognized seller.
With the clutch, you should just leave it as a cable. It's more reliable. Custom parts are hard to get in the middle of nowhere. You can easily carry a spare cable as well.
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Wmax, I hope it is genuine cus I now need a oil tanker load of 'stem cells' to replace the limbs that it cost...!!!!
Another query, (you have to love this site) I need to know the travel length that the clutch cable moves when lever is moved, ie: from rest to full actuation, or to put it another way, the movement of the rocker arm during this action at the point the nipple sits in..? Make sense..?? This is to gauge the spec of the hydraulic ram I will need for the conversion. I don't have the bike set up just in it's raw build stage....
I know what you say is true but im running GS1200 gear and want to go with the hydraulic clutch, sorry...!!! I'll sort it.....
Lol, then it probably is, especially if you got it from a recognized seller.
With the clutch, you should just leave it as a cable. It's more reliable. Custom parts are hard to get in the middle of nowhere. You can easily carry a spare cable as well.
I just went out and measured it. Looks like about 3/4 of an inch of travel at the nipple end. Shouldn't be hard to determine the reduction factor with the transmission lever off the bike.
That being said, the K bikes do not have much clutch travel in terms of actual friction zone. Most of the travel is already fully released or taking up free play (which is necessary with dry clutches, to prevent them from burning out). There is quite a bit of adjustment to correct for clutch wear too. So a hydraulic ram would not need much movement.
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Wmax, I hope it is genuine cus I now need a oil tanker load of 'stem cells' to replace the limbs that it cost...!!!!
Another query, (you have to love this site) I need to know the travel length that the clutch cable moves when lever is moved, ie: from rest to full actuation, or to put it another way, the movement of the rocker arm during this action at the point the nipple sits in..? Make sense..?? This is to gauge the spec of the hydraulic ram I will need for the conversion. I don't have the bike set up just in it's raw build stage....
Spot on Old Bean....!!!! :2thumbup: :bmwsmile
I know what you say is true but im running GS1200 gear and want to go with the hydraulic clutch, sorry...!!! I'll sort it.....
Lol, then it probably is, especially if you got it from a recognized seller.
With the clutch, you should just leave it as a cable. It's more reliable. Custom parts are hard to get in the middle of nowhere. You can easily carry a spare cable as well.
I just went out and measured it. Looks like about 3/4 of an inch of travel at the nipple end. Shouldn't be hard to determine the reduction factor with the transmission lever off the bike.
That being said, the K bikes do not have much clutch travel in terms of actual friction zone. Most of the travel is already fully released or taking up free play (which is necessary with dry clutches, to prevent them from burning out). There is quite a bit of adjustment to correct for clutch wear too. So a hydraulic ram would not need much movement.