Hey everyone,

I just recently got a 98 with around 22,000 miles on it.  I just took it out for my first real ride on the thing and it ran really well and I was having a great ol' time until about 30 minutes into the ride, I was going down a hill at around 55mph and she stalled...

I pulled off to the side, and she wouldn't start up again without me hitting the throttle some.  I upped the idle a bit, but that still didn't help the problem enough (which didn't become apparent until I was back on the road heading home).  I basically did the ride home revving at every stop in order to keep it from stalling (and managed to fail once on a side street).

Every stop was the same it would either rev so low that it would almost stall, or it would stay revving relatively high until I hit the throttle slightly, and then it would drop to almost dead.

I know cars well enough, but know jack crap about Motorcycles.  I didn't have to use the choke on start up, and using it on the road definitely didn't work, so I'm guessing that the fuel mixture might be too rich (there is some discoloration on the exhaust that makes me think that as well).

I haven't looked at the plugs yet to see if they're sooty; I wanted to check with folks first to see if it seems like I'm thinking on the correct lines before taking the fuel tank off, etc. (since I've not done it before, I imagine it'll be a somewhat involved "learning process" )

Thanks in advance for your help.

Definitely get the idle speed up, these bikes have a low oil pressure & the top end will starve at low RPM & wreck the head where the cam spins. Also, with that mileage, unless you know the cam chain has been replaced, you need to pop the clutch cover off & have a look in there. If the tensioner lets go, it is usually curtains for the engine.

Serowbot wrote on 08/12/09 at 19:05:43:

And make sure there's no cracks in the vacuum line!

Thanks for all the advice.  I'll definitely run a load of seafoam through there, and check the vacuum line.  I may take it into a shop anyway and have a mechanic give it a once over, to make sure I don't miss other issues in my inexperience.

Luckily it's a problem that still lets me to ride the bike home, which will allow me some experimentation in trying to fix it (knowing I won't get stranded 25 miles).

CHeck your ignition coil! Could be getting hot and loosing you spark. With that many miles though lots of things to check out also.

Duane wrote on 08/25/09 at 08:00:26:


Update:

I had my parents visiting for more than a week, so I didn't have time to diagnose/mess about until today, but it seems at the very least, the petcock is part of the problem.

I was seafoaming it this afternoon, and it would start and run okay for a bit, and then the revs would drop until it stalled.  Started her back up, and when the revs started to drop, I switched it over to prime and it corrected itself and ran fine.

I did this a couple of times, letting it rev lower each time (once catching it at put....put....put....put range) and each time "prime = running engine"


I was planning to replace the petcock with a raptor petcock anyway, since I'm wanting to go for the "beauty of simplicity" ethic on the bike, in both visual and mechanical, but it's still nice to know the issue.

I'm taking her out for a ride tomorrow morning with a friend (both of us start teaching classes next week, so one last daytime ride before the real world catches us), and will get an on the road test to confirm.

Yep, definitely the petcock.

Took it for a long ride with a friend today.  Up the PCH, into the canyons, back down the PCH, and up Sunset...She ran great the whole time.

I actually need to turn the idle down a bit from where I turned it up trying to adjust for the petcock issue.

Muffler was hot as hell (melted a bit of my motoport pants, which isn't easy), so there's a new thing to check out, but the fuel issue is diagnosed!  Thanks for the help everyone

Hot gases going through a muffler?!?!?!  That's just CRAZY!  

I cannot say how many pairs of waterproof pants, insulated pants, rubber boots I have burned on that d**n pipe.  And those motorcycle covers that have a "heat resistant panel" at the bottom, they burn just as quick as anything else.