First Bike - Couple of Carb Related Questions

[Char]

Hi everyone,

I just purchased a GS as my first bike this week. I've been browsing the forums and going through the Clynes manual researching what to do before I start riding for the season.

The bike is a '98 with 48k kms. Doesn't seem to have any major issues, but I am a little concerned about the aftermarket exhaust. While driving it back after purchase (solid 1hr highway trip) it was pointed out to me that the throttle seemed to stay high when coming to idle. I'm thinking it may not have been rejetted after the exhaust was put on. It also seems to idle a little rough around 1k rpm even after an hour of putting around.

I'm looking at taking the carb out to rejet it since I have no clue if it's been done. I'm having a bit of a hard time finding a Canadian source for parts to rebuild the carb. Please correct me if I'm wrong, but the parts I need are all the o-rings, e-rings, float gaskets, main jets and pilot jets, right? Furthermore, I don't know what kind of exhaust has been put on it, other that it's a Hindle. Should I be looking to put a 150 main jet on it as indicated for many other exhausts in the rejetting FAQ?

Cheers,

[gregjet]

More likely the carbs and cables just need setting up right. Bit of maitenence should be where to start. The bike should run ok without rejetting even with a well flowing exhaust. At least around the low revs. Spec it first then go from there.
Good chance the O rings around the needle/seat for the float need replacing Eespecially if used with alcohol fuels. The bike is pre alki fuels and a lot of the rubber bits have problems with it.

[Char]

So I've picked up most of the pieces to rejet the carbs and replace most of the o-rings, save for a couple of Items arriving during the week. In the mean time I've lubed the throttle and clutch cables. Haven't been able to do the choke as the cable is too tight and I can't back the lock nut off far enough.

So I started it up today to see if lubing the throttle had fixed the hanging idle. It did and didn't - I realized Thursday that the idle was going up when I pushed the throttle-side controls away from me and coming down when I brought them back in. That's been solved. On to the more concerning issue.

Bike stalled on me for a second time this week while hot. Just died when I clutched in while slowing down. Wouldn't start back up until I switched the fuel valve to prime. Today I started it up again on prime (with the choke on), revs went up to 5.5k and stayed there for a good while, until I realized the headers were glowing hot. Backed the choke off completely and put the valve back to the on position and went to a normal idle around 1.2k. I tried revving it and it would slow down on coming back to idle when it hit 4k.

Im tearing the carbs down this week - hopefully it's just a gunked up jet that's making the bike run really lean. I could swear I heard a very faint knocking as well when the rpms would come back down, but it was in the garage the entire time, so maybe it just got too hot.

If you all have anything else come to mind, let me know. I'll probably be looking to check the valves soon too.

[mr72]

The hanging idle is not because it's lean, it's because the idle speed is set too high. It might also be lean, but that's not the cause of hanging idle.

It it dies when on run and won't start unless you put it back on prime then it means the vacuum petcock is closing. Most likely a vacuum leak which can also contribute to running lean and hanging idle. With fresh o rings you should be in good shape.

It could be a coincidence that it started on prime, could be tight valves causing it to stall when hot, then t cools while you fiddle with it and finally is cool enough to start once you get around to trying prime. So the prime thing could be a red herring.