So since my last post, I solved the problem of the K&N lunchbox that the old owner put on by rejetting the mains to 140. Afterwards, it was revving really high. It was a vacuum leak at the lunchbox. I made sure I clamped it well and that was solved.
Today I was really eager to take my bike out. I got it up around campus and through the parking lots a little bit. Then I drove down a main road. I saw that after a while, probably after the bike warmed up, it started to cough a lot. Then, it cut on me right in front of a shopping plaza. I pulled in there. I put the bike on choke and tried to restart it but to no avail. Went inside, got a drink. Maybe waited on my bike for 15 - 20 min. At this point I realized that maybe I should put i on prime. Now I have it on prime. I put back on the choke and it starts. However, it idles really loudly so I take off the choke and the idle comes back down fine. After driving for a while though, it happened again. The bike kind of revved really high while on idle. I pulled to the side and played with the idle screw with the bike running. It died down, but as soon as I drove it off again, it started revving really high. Then, it happened for the second time. It cut on me again. I checked both carb float bowls and found fuel in it so I do not think it is a fuel delivery from the tank/petcock.
I had to get it towed. Way too hot to push it back 8 miles. I'm at a dead end right now though. Does anyone know where I should go from here?
A partially clogged air filter or an ignition issue may be the cause. Both should be easy to check. Take it for a spin (locally) and get it to die on you, then check for spark at each cylinder. If spark is fine, try removing the air filter and take it for another spin to see if it makes a difference.
This sounds a little similar to what happened to my bike.
We cleaned the jets and the carbs, and put in fresh gas with ethanol treatment and seafoam.
I'm not sure if that helps you or not.
I don't think a vacuum leak on the filter side of the carb would cause the issues described since the lunchbox should have next to no restriction already.
When you check for spark once it starts acting up, check for a vacuum leak between the carb and engine as well. Sometimes parts will only leak when they've expanded/softened from the heat.
It may also do you good to double check your fuel mix at idle.
Thanks Xevamir. The seafoam helped tremendously after I also went and cleaned the pilot jets with carb cleaner. Right now it idles pretty smoothly. Sometimes there is a weird sputter out the exhaust which I assume is a result of adding seafoam.
Now that I have the idle a little more smooth, I am having problems with the throttle. As I put it on about a 1/3 or 1/4 of the way, I hear a very loud idle and it kind of hangs before it drops again. The throttle is not very responsive.
I am thinking that I need to shim the needles. Could it be something else?
I think you need to check your valve clearances. How many miles on this engine and when was the last time it was checked?
11,000. I have no idea. The guy I bought the bike from was an intermediate owner and not the original owner so he wouldn't know. The bike hasn't been on the road since 2009.
Again, after the seafoam, it seems to be idling really smoothly just sitting there. No problem I see whatsoever. Anytime I go to crack the throttle about a 1/3 of the way, it will rev really high and have a hard time coming down.
hanging idle sounds like a vac leak. get in there with some carb cleaner and see what you find.
Check for vacuum leaks, but also check your valves. You are past the first valve check interval and running your bike with tight valves will cause damage if you continue to try and ride it. Valves get tighter as the engine warms, so that could explain the problem getting worse after riding it a while. Please check your valves and report back.
Bombsquad, are you saying that the valves could lead to the hanging idle? or was it relating to the general rough Running? If the former, what would the mechanism be?
Thanks
BMF
Quote from: bmf on July 05, 2013, 10:08:22 AM
Bombsquad, are you saying that the valves could lead to the hanging idle? or was it relating to the general rough Running? If the former, what would the mechanism be?
Thanks
BMF
AFAIK, bad valve clearances can lead to both of those issues. As far as the mechanisms, you would have to ask a trained pro.
Quote from: bmf on July 05, 2013, 10:08:22 AM
Bombsquad, are you saying that the valves could lead to the hanging idle? or was it relating to the general rough Running? If the former, what would the mechanism be?
Thanks
BMF
This is entire possible with the valves. hes right valves set tight cold will get worse when warmed up and aggrivate problems, as well as if too loose. also the intake manifolds. if an air leak there, float levels etc etc etc. there are many possibilities
Quote from: bombsquad83 on July 03, 2013, 05:21:35 PM
Check for vacuum leaks, but also check your valves. You are past the first valve check interval and running your bike with tight valves will cause damage if you continue to try and ride it. Valves get tighter as the engine warms, so that could explain the problem getting worse after riding it a while. Please check your valves and report back.
Not so, valves get looser as the engine warms on an overhead valve engine with an aluminum head. Aluminum expands more than steel as it is heated lifting the cams away from the steel valves. If you have cold compression and valves are not excessively noisy when hot then they are not affecting the running of the engine but don't let them go too long between checks because exhaust valves that are run on the tight side of the Suzuki spec will recede into the seats over time causing damage. Need more clearance than Suzuki spec for long engine life.
Hanging idle on 2 circuit carbs (89-00) is caused by too lean a mix and gets worse as engine gets hotter. My brand new 97 GS had hanging idle hot but I managed to adjust it out with idle speed adjustment the first summer and it was not a problem after that, put over 20k miles on it the first year so it was an old bike by the second. :icon_lol: