gsx750es carb problem?

[Anonymous]

i own a 1983 gsx750es which ,at this present time will run smoothly on all 4 cylinders under normal road use.
from time to time it feels "sluggish" and when on tickover,it only runs on 3 cylinders.if you rev it ,all 4 start to work.does anybody have any idea whats wrong?your help would be appreciated.

 

[moto_dan]

Re: gsx750es carb problem?

from time to time it feels "sluggish" and when on tickover,it only runs on 3 cylinders.if you rev it ,all 4 start to work.

Which cylinder stops firing? When my '83 experienced similiar symptoms, it was the #2 cylinder and it turned out to be a small hole in the diaphram of the petcock. As a quick test, pull the vacuum line from the petcock to intake and check for any fuel in the line. If fuel is present then the diaphram is leaking and the petcock will need to be rebuilt or replaced.

 

[Anonymous]

the two outside cylinders are not firing on start up.rev it,and they all work..
summer does not last long in England.....!!!!!!!

 

[moto_dan]

the two outside cylinders are not firing on start up.rev it,and they all work..

What have you done to this point to isolate the problem? Since
#1 and #4 cylinders share the same coil(I think), I would eliminate the possiblity of a bad coil first, then go to the carbs. Swap your coils and see if condition moves to #2 and #3.

 

[Billy Ricks]

the two outside cylinders are not firing on start up.rev it,and they all work..

What have you done to this point to isolate the problem? Since
#1 and #4 cylinders share the same coil(I think), I would eliminate the possiblity of a bad coil first, then go to the carbs. Swap your coils and see if condition moves to #2 and #3.

Good advice Dan. Switch the inputs on the coils so the 1 & 4 coil will fire 2 & 3 and vice-versa. You might have to switch the plug wires on the coils around if they won't reach the plugs.

 

[Anonymous]

gsx750 carbs

gsx750 carbs

thanks ,dan+billy for your advice
......i have some spare time tuesday21.05.02 so i will test out the coils as you suggested. and post a reply.
it's a great bike but it's doing my head in at the moment!!!!!!!!!

 

[Anonymous]

i changed the coils/wiring over.............still the outside cylinders(1+4) stop while the bike idles.....you were right dan,1+4,2+3,
what next?.....scrap it? only joking..buts that's what i feel like doing right now!!

 

[moto_dan]

i changed the coils/wiring over.............still the outside cylinders(1+4) stop while the bike idles.....you were right dan,1+4,2+3,
what next?.....scrap it? only joking..buts that's what i feel like doing right now!!

Do you have a manual for your bike? So your bike fires on all four when off idle? If yes then your carbs could be out of sync, air/fuel screw misadjusted, dirty carbs. Personally I would probably check the syncronziation of my carbs first since it does not require any disassembly, if you have that capability.

 

[Anonymous]

coils checked out ok
i dont have a manual.i have just advertised on suzuki owners club web site u.k.(similar to gs resourses)
i spoke to a local dealer who seems to think the problem lies with the idle jets on 1+4 being blocked..
the previous owner did approx.2500miles in 9 years.so its a possibility
so is dirty fuel.next step is to srtip down and clean the carbs.
the carbs were recently balenced

 

[moto_dan]

coils checked out ok
i spoke to a local dealer who seems to think the problem lies with the idle jets on 1+4 being blocked..the previous owner did approx.2500miles in 9 years.so its a possibility so is dirty fuel.next step is to srtip down and clean the carbs. the carbs were recently balenced

Sounds reasonable to me. The carbs could use a good cleaning and there is an excellent "how to" article on this site. Keep us informed and Good luck.

 

[Anonymous]

thanks for your help + comments
i will post a reply as soon as the problems fixed..
but due to work comitments i wont be able to do any thing until early june

 

[Anonymous]

last w/end i stripped the carbs down and gave them a good clean,and used a compressor to blow the jets through
put them back in and..................same as before
fires on all 4 for4/5mins then 1+4 stop...rev it to3.5/4k and all four run again smoothly for 4/5 mins
there is a smell of fuel from the exhaust when you rev it so it would appear that fuel is going in
today i inspected the 1+4coil and found the coil end of the HT leads corroded.i have replaced the coil and HT leads .....still the same probs.