Hey guys, I've just bought a 1990 Suzuki GSF250 as a non-runner and have finally got it running. By cleaning the carbies and adjusting the pilot screws it now runs and idles great, and revs freely WITHOUT LOAD. So I thought the bike was all good, took it out for a test ride today and opened it up and it went great, revved to about 10,000rpm without any troubles and was great; but then I turned around and went to come back home and the engine died. I got it started again but had to have open throttle to allow it to idle (very roughly) and it wouldn't go past 2000rpm. I kicked it into neutral and tried to rev but exactly the same problem, idles at 2000rpm and won't go anymore. Anyways I managed to put home in 6th gear at 2000rpm and now that it's back in the driveway it's revving freely again? Just wondering what ideas people have as I'm pretty stumped. The guy I bought it off had this exact issue (he bought the bike, opened it up and it went and then putted home; but he couldn't get it started since). Thanks in Advance, Jacob
Firstly welcome along! i wonder if its an excessive air leak in the carbs or starvation of fuel? have you checked all the breathers lines and fuel lines in?
It could be flooding. Does the bike have a fuel tap? If so, if it does it again, turn off the fuel tap and open the throttle to start draining fuel from the carbs. As the fuel level drops the revs will pick up again
Hi sorry to hijack your post but........... I have exactly the same problem with my 89 250 Bandit. Bike runs fine from cold for about 15 minutes or so but then once hot it dies and then is hard to start. When it starts it runs at around 2000rpm wherever the throttle is positioned. Sometimes it will then rev up normally only to die again 2 minutes later. When this happens it appears the bike is running rich as there is a strong fuel smell and excess smoke coming from the exhaust. I have cleaned and balanced the carbys twice so are now looking at electrical issues. Once again this only happens when the bike is hot. I have a theory that the coils are overheating but have no idea how to check this.
Fuel tap problems very common with this bike, the vacuum petcock and all. Not sure if that's the issue but I wouldn't be surprised. I have a '92 GSF250 parts bike I'm stripping down if anyone needs anything.
My two cents, 90% of coil problems would actually be the TCI unit. After all there are only a gazillion things that can go wrong with your TCI and about 2 for your coils.
Afternoon all (well, it's afternoon here . I have a 1990 GJ74A with exactly the same issue being described in this thread. It stood for 5+ years before I got my hands on it. I've replaced the plugs (twice now) and cleaned the carbs. Still the same. Just wondering if you got to the bottom of the problem?
I would look at the fuel tap mate. The diaphragms on them tend to split so you might be flooding it without realising. Also check your oil to make sure it doesn't have fuel in it.
Previously suggested on the forum and known issue with the mikuni carbs (FZR/GSXR/Cobra etc running bdst) emulsion tubes/needles, likely worn out of round
Thanks for the advice guys. I drained the tank and pulled out the fuel tap. Diaphragm appears to be ok (passes the suck test). Stripped it down. Bit gungy, but all looks OK. Will clean it up and put it back together tomorrow and see what we get.
Na, bike still not running right. Idle is rough, and it sometimes stalls. And it won't pull from low RPM. Got to have 6k+ on the rev counter to pull away...
