desperate

[bikechump]

Hello, its me again, with another problem.

Ive got an 82gs400. its been running superb until went to go to school this morning. The motor now lacks power although the revs continue to climb, and no does not have a steady idle. i would adjust the idle screw so it idles just under 15hundred but after giving it a shot of throttle and then backing off it will climb up to 3 - 4 thousand unless i backed the screw out. after i would back the nob out it would idle ok for around 5 - 10 seconds and then slowly die unless i gave her a quick punch of gas. Once i got home i tore into my carb thinking it had something to do with the fuel delivery. Unfortunately i could only work on it at home so i didnt have access to compressed air. I did what i could. cleaned emulsifier tubes, screw next to that under a rubber plug (pilot jet)? checked diaphrams(fine) . Ive read threads that were related to this and responses came back about air leaks. i tried the good old wd40 on the boots(nothing) made sure clamps were tight. btw. boot o rings are new.

My petcock has never really worked properly as i would have to always run it in prime (worked great in prime though) perhaps a culprit?

My biggest concern lies in the fact that some mornings my cylinders would accumulate fuel from over night. When i would go to start the engine it compresses it and stop the starter motor. I would just wait for the pressure to dissipate and then try again, resulting in it starting right up. Now is there a chance of having a bent valve because of hydraulicing the engine?


I guess i'll have to ride a bicycle to motorcycle school until i can resolve the problem. Thanks in advance . vince

[UncleMike]

Sounds like a new petcock and new rubber for the carbs is in order.

[koolaid_kid]

If you do have to run it in the prime position, turn the petcock off when you get off the bike. This will prevent the fuel from running into the cylinders.
You should probably go ahead and rebuild the carbs (kits should be available) since that is an indication that the needle and seat are worn.

[Road_Clam]

Hello, its me again, with another problem.

Ive got an 82gs400. its been running superb until went to go to school this morning. The motor now lacks power although the revs continue to climb, and no does not have a steady idle. i would adjust the idle screw so it idles just under 15hundred but after giving it a shot of throttle and then backing off it will climb up to 3 - 4 thousand unless i backed the screw out. after i would back the nob out it would idle ok for around 5 - 10 seconds and then slowly die unless i gave her a quick punch of gas. Once i got home i tore into my carb thinking it had something to do with the fuel delivery. Unfortunately i could only work on it at home so i didnt have access to compressed air. I did what i could. cleaned emulsifier tubes, screw next to that under a rubber plug (pilot jet)? checked diaphrams(fine) . Ive read threads that were related to this and responses came back about air leaks. i tried the good old wd40 on the boots(nothing) made sure clamps were tight. btw. boot o rings are new.

My petcock has never really worked properly as i would have to always run it in prime (worked great in prime though) perhaps a culprit?

My biggest concern lies in the fact that some mornings my cylinders would accumulate fuel from over night. When i would go to start the engine it compresses it and stop the starter motor. I would just wait for the pressure to dissipate and then try again, resulting in it starting right up. Now is there a chance of having a bent valve because of hydraulicing the engine?


I guess i'll have to ride a bicycle to motorcycle school until i can resolve the problem. Thanks in advance . vince

Your issues are the all too familiar tale of simply old, dirty GS carbs and/or carb boots. First off sounds like you definately need new inlet needles (overnight leaking fuel into cylinders). The erratic idle is most likely a old, dry-rotted intake boot. If you bike accelerates ok from a dead stop it's most likely an air leak. If you have a bad stumble or no idle, thats a sign you have dirt in the pilot jets.

[jeddininja]

Bikechump
this is all good advice, but don't forget to check your oil. If one of your jugs is filling with gas, it'll have to go somewhere. It'll most likely seep past your rings into your oil.
Sorry to pull up an old post, hopefully you thought of this already.

[SqDancerLynn1]

From your post you need to replace the petcock before it does any damage. CHANGE the oil. After you do that it will probably run right. RPM will increase when it runs lean/ out of fuel Usually the only rebuilding of the carbs is to replace the O rings. Buying (junk) repair kits is a waste of money Get a O ring kit from cycleorings.com

[bikechump]

thanks for the replies, i'm going to take my carbs to school tomorrow so i can use their carb dip, compressed air. Hopefully they have an o ring kit i can steal some o rings from. i went over the carb rebuilding section of this website, clever idea concerning the match stick with a cut wire from a brush.

OH ive been thinking about my flooding problem and forgot to mention it gets worse when parked with the front end lower then the rear and ofter corrects itself when inverted. Not to long ago i replaced my seat/needle with nice rubber tipped ones so that cant be the problem. Im suspecting my floats could be set too high. I'll have to read my manual to see how to do that, ive seen people use a hose connected to the drain plug on the bowls and bend them up as to show where the level is. Do you guys have any tricks when attempting this?

I know im going to get a lot of flak for this but what do you guys thing of an inline ON/OFF valve just after my petcock. seems like a good idea since the petcock doesnt leak and a new one would cost around 100 bucks compared to a 10 dollar valve. (i consider myself resourceful, some mistake it for being cheap :-D) Not working right now so i like to save money where i can and use that for other things for the bike.

I tore my petcock apart initially to see how the vacuum mechanism worked and maybe by luck fix it. Put it back together and no fuel would flow in any of the positions, i put a hoes up to the vacuum and sucked. HEY it flows but now it wont stop! One smelly garage later i realized the spring i bent taking it apart may have actually mattered.

wow that was quite the rant. i attached a picture of the bike since no one has seen it, hope it works. thanks again:mrgreen:


vince

[salty_monk]

There's another post on here (still current) that tells you how to turn your vac petcock into a non-vac. Seemed fairly straight forward & bearing in mind your money situation it would also be free apart from your time...

Dan

[argonsagas]

Putting in an ON/OFF connector is a good idea if you cannot get the petcock repaired, but it would be basically doing what the petcock is supposed to do.

Your floats are definitely not working correctly and/or your bowl needles are not seating and stopping the fuel flow.

You M U S T check the oil for gasoline seepage.

If you smell gasoline, then the oil must be dumped and the filter has to go as sell. Replace the oil and put in a new filter.

There is no point in refilling the oil sump until the fuel system is repaired, as you will only repeat the problem.

[jeddininja]

SqDancerLynn1 has it right. I should have been more clear. You don't want to run the bike if you have fuel in your oil. It WILL damage your engine.

As far as the petcock, take it apart and soak the metal parts in carb cleaner. inspect the rubber parts for damage and get them as clean as you can. hopefully you havn't lost/destroyed the spring. For some reason, all the parts in this design are required for it to work properly...

At any rate, even if the petcock sticks open, you shouldn't see problems with fuel leaking into the engine. This part seems like a float issue (since you've already replaced the needle valves). Make sure the floats are properly adjusted or you won't get the bike to run right. you may also want to look at the floats and make sure they still float. Maybe someone can verify this for the suzuki, but i have seen floats go bad (rarely).

There is always the possibility that you've gotten some crud in the needle valve seat, depending on how well you've cleaned the carbs.

Another thing to look at is the airbox. If the fuel is still leaking when the frontend is higher than the backend, it'll run into the airbox. That's just as dangerous as having it leak into the cylinder. Maybe even worse, unless you are fond of having your machine go out in a blazing ball of glory...
I would stay away from the manual (additional) fuel valve. Just another opprotunity for things to go wrong.

ok. i'm off to find the thread on converting from vacuume to manual. could come in handy...

[Nessism]

At any rate, even if the petcock sticks open, you shouldn't see problems with fuel leaking into the engine.

Lots of people don't understand this point. The needles control the fuel flow into the carbs, not the petcock. Fix the problem at the source. Petcock is secondary repair, not primary.

[bikechump]

status report

thanks for all the responses.

I think ive cured the flooding problem by cleaning the float needle and seat. I purchased a new petcock in hope of solving my idle problems. After my first test ride i thought i had fixed the idle issue but after riding it home and allowing it to fully warm up pops up again. i bought new spark plugs after my old ones have been fouled from running rich. i screwed in the idle mixture screw with good results, plugs now look brown/light gray.

I would like to emphasize that this problem occurs after the bike has been given a good warm up. the revs will stay just under 2000 and then slowly die if i dont tease it with a little throttle.when cold it idles perfect.

prior to buying a new petcock i checked for any air leaks on the carbs and found one on the seal leading into the bodies from the throttle linkage actuating the butterflies. i was told these seals are extremely difficult to find so i left it on the burner.

On i side note, would a poor sealing plug covering the pilot jet(i think) cause these symptoms? (both are there just not tight enough to make me confident its air tight)

thanks in advance.

vince

[nabrams]

Deal with that air leak first before moving on to further diagnostics. That air leak will make any other testing almost meaningless. See tons of posts about air leaks.

[bikechump]

back in business

After giving it some thought i decided to check the valve clearances since the problem seemed to occur after it reached operating temp. Since i haven't been in there since i bought the engine i figured it might be a good idea. Found a pair of exhaust valves on one cylinder to what seemed to have zero clearance and a pair of intake on the other cylinder in similar shape. i could tell someone had been in there because some of the cam cover bolts had been placed back in the wrong holes(short bolts where long ones should have been, visa versa

Anyhow took the bike for ride after school taking a longer route home to get the engine nice and hot. HEY it idles

Im still going to address that air leak in the carb once i can get a hold of that seal. As stated earlier i don't know how much luck i'm going to get finding that one. ( i might have to pull a guyver and use some jb weld but that will be the last resort.)

It sure feels good and reminds you that all those days spent beating yourself over trying to figure out the problems is worth it. Thanks again guys. talk to you later (hopefully not too soon)

vince

[UncleMike]

F*cking valves.