why Johnny blanket, why?

[ermach]

coincidence or not? I recently gave up thigh roasting here in Texas on my 87 K75. Went to home depot, got the reflective stuff, jammed it where it goes, things are good thighs are great. What is not great is that if I go on a short trip, shut the bike off, then go to leave, I am now riding a bucking bronco for a good 2 minutes. What I mean is crazy hesitation, sometimes stalling and general bad times, especially when your short trip was to fuel up, right before you get on the freeway with no shoulder and a line of cars backing up behind you in Dallas morning rush hour, not that it happened, except I just described my commute to work this morning. This has happened only since the blanket mod, and has happened a few times. I've tried opening the gas cap, there is no suction noise, but I feel like some weird vaccum is happening preventing proper fuel flow. After a bit it clears up, and doesn't happen if I make one continuous trip somewhere, like to work. Riding home is no problem after it sits all day. My bike lacks the rubber bits that block the fan exhaust, so it really is almost unrideable here in Texas. I have replaced the 2 vent lines that come off the tank on the right side earlier this season. had been fine until the blanket. ideas?
Eric

[johnny]

first thing I would do is clean up the 4 pin under tank fuel pump connector and the jetronic connector... then I would swap in a new  napa 3032 fuel filter.. then if it still bucked I would look in the tank to see if the gas is boiling while it is bucking...

j o

[ermach]

I'll look into the connector, but it seems like the tank should be cooler, provided the shielding I just installed, no? I guess anything is possible though. I feel like I'm missing parts on the under tank side of things. I know that one of the lines is the drain line to keep water out of the tank, but is the other just a vent? I just have 2 hoses running down to the right footpeg. I've read some things about a cup, collector, or something that others have down there, I think? I also know I need to do some tune up like activities such as plugs, crankcase breather vent and so on. All my rubber is dying at the same time. Thanks for the suggestion, and others are welcome too!

[mac]

I feel like I'm missing parts on the under tank side of things. I know that one of the lines is the drain line to keep water out of the tank, but is the other just a vent? I just have 2 hoses running down to the right footpeg. I've read some things about a cup, collector, or something that others have down there, I think?

Both are essentially vent hoses. The accumulator "cup" clips onto the frame under the two nipples and has a drain line of its own, so it's kinda a 2-into-1 deal, with the major advantage that you don't have to connect/disconnect those vent lines every time you want to remove the tank.

FWIW, the front line originally went into the crankcase as a kind of half-ass evaporative emissions control. Generally this line from the crankcase just gets plugged.

More info (minus pictures unfortunately) http://www.motobrick.com/index.php?topic=989.0

[Grim]

I have the blanket and one of the best mods Ive done to the bike. My tank does stay considerably cooler.

I also think something was disturbed when installing the blanket. Many of us have found issues with connectors needing a little cleaning and a little die electric Grease. I had some intermittent run issues that were traced back to some electrolysis corrosion in the ECM plug. Little contact cleaner and the grease and its been happy ever since. Id pull the tank back off and check all the connectors under there to the ignition, kill switch and tank. Also check the big ground lug under the tank.

 

[ermach]

thought I was good, but being on the side of the highway is not good. Last night I replaced the 4 pin connector under the tank with a trailer wiring set. Started right up after that. Took the Captain Ron approach "if anything's gonna happen, it's gonna happen out there" and didn't test ride it. I was confident I had this thing beat. Well, about 20 minutes into my work commute, in the fast lane, bike stalls and I'm coasting. Wouldn't start after that. Had to call the fiancee for a pickup. I didn't check the ecm plug, but will tonight. I feel like I need to get into the tank as well and see if all the connections in there are ok. Anything else I should be looking at. I've got plugs on the way. I feel foolish that I got this bike to save on my commute dollars, and all I'm doing is tossing money at this bike. Seems like I should have stuck with the DR650.  :musicboohoo:

[motodude]

Johnnyblanket aside, does your K75 still have the insulation on the fuel lines?  It should have come that way from the factory but they often get removed.  Basically a set of foam rubber hoses over the fuel hoses.  There are other ways to insulate them and I believe there are some instructions here somewhere.  If you're riding in hot weather, I'd look into them.

Another thing, does the bike die suddenly and only when warm/hot?  If so, it may be your hall-effect sensors going bad.  Difficult to troubleshoot as they're often intermittent.  To buy the entire unit is expensive.  There's a guy on the ibmwr list that will sell you the individual sensors at quite a savings.  You'll have to drill out the existing rivets and rivet the new ones in.  It sounds like surgery but it can be done and saves a gob-o-bucks.

Tom

[ermach]

Do you mean inside the tank or outside? I know for certain that there is no insulation on the outside lines. I'll report back on the inside. It doesn't seem to be heat related, bc the hall effect sensor shuts down when warm, right? It still wouldn't start after I got back home about an hour later. It's been fine in 100 degree stop and go traffic before, but I suppose that doesn't mean the sensor isn't going bad now. The new connector was pretty warm when I unplugged and replugged it on the side of the road. nothing looked damaged though. I'll take a look on the other site for the sensors. I'm definitely going to explore what's going on in the tank first though. I feel like there is a loose connector somewhere fuel delivery wise. Hope I get this sorted. I am starting to feel like I got taken on this bike, which I traded for.

[TimTyler]

Have you popped in a new fuel filter yet?

[ermach]

yes, new fuel filter in the last 500 miles or so. I had to since the p.o. had the fuel cap installed backwards, so after a rain, water got into the tank since there was no drain hole open. Maybe the filter for pump has some junk in it. when I put the new fuel filter in, there was a ton of crap in the tank and the fuel looked like pumpkin juice. maybe not that bad, but there was a ton of stuff in there. I ended up vacuuming out all of the junk. I didn't take a look at anything else, since I wasn't having any of these issues back then. This has to be something easy that I'm just missing. I do find myself on craigslist looking to trade these troubles away though.

[TimTyler]

Sounds like you might have crap throughout your fuel system.

I don't know if fuel pumps can be back-flushed (reverse polarity?) but that and a screen cleaning might be prudent.

Your injectors might be clogged up too? http://www.mrinjector.us/ Inexpensive fix.

[ermach]

the more I'm reading about this the more it sounds like a wiring issue at the fuel level sender side of things, at the tank. When I get home I'll have to see if I can tap the tank and have it start or tug on the harness that goes to the tank.

This article seems pretty close to what I'm dealing with. When it runs, it's great. Whenever it wants to stop, it does. At least I haven't rented trailers non stop as this guy had to.

http://www.k11og.org/forum/viewtopic.php?t=8412&postdays=0&postorder=asc&start=45

[motodude]

Do you mean inside the tank or outside? I know for certain that there is no insulation on the outside lines. I'll report back on the inside. It doesn't seem to be heat related, bc the hall effect sensor shuts down when warm, right? It still wouldn't start after I got back home about an hour later. It's been fine in 100 degree stop and go traffic before, but I suppose that doesn't mean the sensor isn't going bad now. The new connector was pretty warm when I unplugged and replugged it on the side of the road. nothing looked damaged though. I'll take a look on the other site for the sensors. I'm definitely going to explore what's going on in the tank first though. I feel like there is a loose connector somewhere fuel delivery wise. Hope I get this sorted. I am starting to feel like I got taken on this bike, which I traded for.

The lines on the outside of the tank.

The HE sensor, once it decides to stop working, may take a while before it will work again.  Sometimes they do and sometimes they do not.  They are difficult to diagnose..