Alex687 Posted September 18, 2016 Share Posted September 18, 2016 So I recently gave my engine and carb a bit of an overhaul. I tried to revert all the carb settings to as they were but I'm not sure how good a job I did. I've never owned a vehicle with a carb before this and am only just learning how they work. Anyway I've been having a bit of trouble with it since putting it all back together. It's rather difficult to start when it's cold. Before I took it apart it started no problem. It has a choke operated by a lever on the handlebar. There is some adjustment in the cable where it attaches to the carb but I have absolutely no idea how it should feel at the lever, and how it should behave in terms of engine running. Haynes was very vague, mentioning something about a bit of play but not too much play in the lever. This was very unclear. So eventually I can get it started using the choke but it behaves wierdly as soon as it's going, and I find that I quickly have to close the choke and just give it some throttle until its warm before I can leave it to idle without it cutting out. Once it was warm I decided to set the idle screw for a desired idle of around 1700rpm which is fine. But I then find that if you leave it to idle, the revs creep up over 10/15 seconds to around 3000rpm. If you then blip the throttle a bit and let it go, it returns to 1700rpm (ish) before doing the same thing again. I was thinking maybe this is something to do with the choke not being fully closed... or perhaps the float height isn't quite right so during the time that the revs rise, the float bowl is actually filling until the float closes the valve. I don't know! I need some advice or need to find someone to give the carb a proper tune and setting up. I thought I'd check here first for any advice. Link to comment Share on other sites More sharing options...
KevtheRev Posted September 19, 2016 Share Posted September 19, 2016 Did you make any changes to the idle mixture screw settings ? generally you should note the position of this before removal and ensure it is the same after refitting . you should have a little slack on the choke cable to ensure the choke is not being activated when it shouldn't be . Link to comment Share on other sites More sharing options...
Alex687 Posted September 19, 2016 Author Share Posted September 19, 2016 I may be wrong but I'm pretty sure the two jets within the float bowl were screwed all the way in so I returned them to this. and only the one jet accessible from the outside of float bowl was set in a particular place. I returned this to original posituon. Excuse me for not knowing which jet is which. I believe the two inside at the main jet and idle jet. The adjustable one is pilot jet? So confusing! Someone at work has suggested a possible vacuum leak on engine side of carb. Will investigate this and maybe replace some clamps and o ring seal. 1 Link to comment Share on other sites More sharing options...
finnerz89 Posted September 19, 2016 Share Posted September 19, 2016 Easy way to check for air leaks is spray some wd40 around the joints when the bikes running. If the revs pickup then you'll know you have a leak Sent from my E6553 using Tapatalk 1 Link to comment Share on other sites More sharing options...
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