Hello, I recently bought a cheap CBR250RR MC22 1993.
It wasn't working at first and I found this to be a bad connection in the wiring which has now been fixed.
Now i've managed to get it to start a few times, the idle will start out normal but the rev's will quickly climb without me touching the throttle at all.
If I stop the engine and start it again right after the revs will start from where it was last time. So for example the first time I started it it revved up to 5k rev's. I then killed the engine and started it again and it started from 5k and revved up to 7-8k, where it seems to stop going up. When it was doing this revving thing I tried to give it some throttle and the revs actually went down... Also there was a bit of white smoke coming out the exhaust, and the first time I started it there was petrol (or oil?) inside the tip of the exhaust.
I'm pretty sure this has nothing to do with the throttle cable or idle screw as I took the carbs off and gave them a clean and all that seemed to be working as it should.
One thing I noticed when cleaning the carbs was one pilot screw was different from the rest, and also the O ring seems a bit worn. Apart from this everything looked okay (to me).
I'm not really sure what to try next. The guy who sold me the bike said he went overseas for a month and came back and it wouldn't start.
He also said that recently it has had new spark plugs, oil filter, fork seals & rear tyre fitted.
I have checked the spark plugs and they looked normal.
I'll probably change the oil next, when I checked it the dip-stick smells a bit like petrol... is that normal?
Other than that all I can think of is to buy new rubber boots connecting the carbs to the manifold. When I removed the carbs I actually only got one boot off the manifold and the rest I couldn't remove. I couldn't see any obvious damage but some were a little frayed.
Also I will probably order new o-rings and gaskets for the carbs as well. But I though i'd post here first and maybe I can find out what's wrong and if it can even be fixed before I start ordering parts from overseas. (I live in New Zealand)
Hopefully someone can tell me what's wrong. I can also try start it again and upload a video if that will help, but i'll have to jump start it as the battery has gone flat now.
Also I have pictures of the pilot screws and how one is different which I could upload if it helps, also have pics of the spark plugs from when I removed them.
Thanks!
Edit: Also I had some trouble getting it to start after cleaning the carbs, I guessed this is probably from incorrect pilot screw settings? I set them to 1 and 3/4 turns. (I stupidly didn't note what they were originally). It did eventually start and was doing the same revving thing.
It wasn't working at first and I found this to be a bad connection in the wiring which has now been fixed.
Now i've managed to get it to start a few times, the idle will start out normal but the rev's will quickly climb without me touching the throttle at all.
If I stop the engine and start it again right after the revs will start from where it was last time. So for example the first time I started it it revved up to 5k rev's. I then killed the engine and started it again and it started from 5k and revved up to 7-8k, where it seems to stop going up. When it was doing this revving thing I tried to give it some throttle and the revs actually went down... Also there was a bit of white smoke coming out the exhaust, and the first time I started it there was petrol (or oil?) inside the tip of the exhaust.
I'm pretty sure this has nothing to do with the throttle cable or idle screw as I took the carbs off and gave them a clean and all that seemed to be working as it should.
One thing I noticed when cleaning the carbs was one pilot screw was different from the rest, and also the O ring seems a bit worn. Apart from this everything looked okay (to me).
I'm not really sure what to try next. The guy who sold me the bike said he went overseas for a month and came back and it wouldn't start.
He also said that recently it has had new spark plugs, oil filter, fork seals & rear tyre fitted.
I have checked the spark plugs and they looked normal.
I'll probably change the oil next, when I checked it the dip-stick smells a bit like petrol... is that normal?
Other than that all I can think of is to buy new rubber boots connecting the carbs to the manifold. When I removed the carbs I actually only got one boot off the manifold and the rest I couldn't remove. I couldn't see any obvious damage but some were a little frayed.
Also I will probably order new o-rings and gaskets for the carbs as well. But I though i'd post here first and maybe I can find out what's wrong and if it can even be fixed before I start ordering parts from overseas. (I live in New Zealand)
Hopefully someone can tell me what's wrong. I can also try start it again and upload a video if that will help, but i'll have to jump start it as the battery has gone flat now.
Also I have pictures of the pilot screws and how one is different which I could upload if it helps, also have pics of the spark plugs from when I removed them.
Thanks!
Edit: Also I had some trouble getting it to start after cleaning the carbs, I guessed this is probably from incorrect pilot screw settings? I set them to 1 and 3/4 turns. (I stupidly didn't note what they were originally). It did eventually start and was doing the same revving thing.