G'day All, Having rebuilt the engine, put it back in the bike I want to test ride it! Unfortunately the cold start does not seem to work for me! Whilst on "choke" I do not use the throttle and the bike starts and runs for a couple of seconds then dies. Repeating the process a number of times I can get it warm enough to actually run, and like this it runs very nicely. As far as I can tell everything (except perhaps the exciter coils) seems to be as it should be - float height looks good, plugs new and wet. The exciter coils had a problem (dry joint on the low speed one - now fixed, but the resistance of the exciters is a bit low - low speed down 10%, and high speed down nearer 15%. Could this cause the problem? My only other thought is the petrol is going off - been in the can for over a month. Any suggestions, Arthur
Start with fresh petrol so you can be sure. The choke is really an enriching circuit in the carb to provide more fuel, so is it absolutely clean and clear? What happens when you open the throttle? I don't think that 10-15% would make much difference to the coils at starting speed.
G'day Murdo and many thanks for your reply. Using the throttle at all when the engine is cold and it will not even fire. If I use the throttle when the engine is running for its few seconds it dies immediately. Today however I drained the tank and put in fresh new stuff. After just a few kicks it started and was responsive to the throttle, so with a bit of luck that problem is now behind me, and I can get a ride on the bike. Cheers, Arthur
By a can of threebond, take apart the carbs and soak all of the jets in threebond for a while. Rinse with hot water when done and put it all back together.
Two strokes - spark, air and fuel. I wouldn't jump straight to pulling your carbs apart. Also curious your fuel went off after a short period of time - I can start my two strokes with 3+ month old fuel no issues. I have found that a proper state of tune is critical especially if you have a multi carb set up and you don't use the bike that often. Clean plugs too cause if you've done short runs they can foul up. I always carry my spark plug spanner and a spare when I ride the two strokes. Best thing Arthur is take her for a good ride, get her nice and warm then see what happens.
Be sure she's not got an inlet seal leak or a crankcase leak, sounds like she might be running lean / sucking air into the mix. Be careful if you take it out for a ride that she doesn't nip up or burn a piston or you'll be doping another engine rebuild. One good test is to seal up the inlet & exhaust & somehow fit a valve where you can pump up the crankcase with a little pressure & see if it holds, if it leaks then there's a leak, maybe a seal or a gasket, you can spray the joints with wd40 or anything soapy water & check for bubbles. Check your inlet phenolic spacer in front of the carby & see if there a crack or a crook gasket.
