Engine bogging and backfiring..

last year there were CDI units that backfired a while before dying - unlikely though

I'd still be checking for head gasket leaking.
 
last year there were CDI units that backfired a while before dying - unlikely though

I'd still be checking for head gasket leaking.
theres no leakage. :( I did take the carb apart because it was running rough and taking FOREVER to get up to speed.... it does eventually get up to speed but takes AGES, it is real hard ot get it to idle as well. it was like that since i got it, every now and again i had to give it a rev to keep it going... I'm thinking its sucking air from the carby bowl because its leaking from there and some of the gasket is popping out...
 
The pistons and rings look perfect.
Glad to hear the piston rings and cylinder is good. The backfire is the odd symptom. Jag may have something with the woodruff key. I've just never seen the one on the magnet side go bad. There is really no load there, still worth looking at. air leaks around the carb generally cause high revs that can't be controlled with idle adjustment. was it a backfire through exhaust or a spit through the carb. Is there any fuel in your clutch or magneto covers?
 
Glad to hear the piston rings and cylinder is good. The backfire is the odd symptom. Jag may have something with the woodruff key. I've just never seen the one on the magnet side go bad. There is really no load there, still worth looking at. air leaks around the carb generally cause high revs that can't be controlled with idle adjustment. was it a backfire through exhaust or a spit through the carb. Is there any fuel in your clutch or magneto covers?
I'll check now
 
Glad to hear the piston rings and cylinder is good. The backfire is the odd symptom. Jag may have something with the woodruff key. I've just never seen the one on the magnet side go bad. There is really no load there, still worth looking at. air leaks around the carb generally cause high revs that can't be controlled with idle adjustment. was it a backfire through exhaust or a spit through the carb. Is there any fuel in your clutch or magneto covers?
Everything looks perfect, the motor is new so i wouldn't expect anything tobad, is it possible that it is the carby?
 
theres no leakage. :( I did take the carb apart because it was running rough and taking FOREVER to get up to speed.... it does eventually get up to speed but takes AGES, it is real hard ot get it to idle as well. it was like that since i got it, every now and again i had to give it a rev to keep it going... I'm thinking its sucking air from the carby bowl because its leaking from there and some of the gasket is popping out...
It is more than likely the shut off needle in the float bowl not sealing. If it is not stopping the fuel from flowing in the fuel runs out of the carb even if the gasket is good. It also fills up your crank case with raw fuel and makes the bike run like crap. Clean the bowl, float needle, and needle housing with carb cleaner. Make sure the float doesn't have a leak. then bend the float tines a little and check if needle is seating all the way. It will take a little while to get all the raw fuel out of the crank case. If you can get the rear wheel off the ground and pedel it with the plug out you will get a lot of it out without fouling the plug. You will probably see fuel coming out of the exhaust. Just curious, the day this all started did you happen to leave the gas on over night?
 
Everything looks perfect, the motor is new so i wouldn't expect anything tobad, is it possible that it is the carby?
With what you said about the carb leaking I would bet the float needle is the trouble maker. I've seen a lot of brand new carbs leak like pigs. When the raw fuel gets in the crank case it runs like s**t. If you can't get it to stop leaking through cleaning and float adjustment get a new one and keep the old one for parts.
 
With what you said about the carb leaking I would bet the float needle is the trouble maker. I've seen a lot of brand new carbs leak like pigs. When the raw fuel gets in the crank case it runs like s**t. If you can't get it to stop leaking through cleaning and float adjustment get a new one and keep the old one for parts.
Should i put my racing carb on? its got the wrong jet but i've bought a jet set from china.. it will run alot slower with it on but i'll have to make use of it until the jets arrive, it that a good idea?
 
Also when i took the carb apart i did notice the bit that the float pushes up to close the line gets jammed if u give it a nudge...
 
Should i put my racing carb on? its got the wrong jet but i've bought a jet set from china.. it will run alot slower with it on but i'll have to make use of it until the jets arrive, it that a good idea?
I think that's your best bet right now. Is the racing carb the delorto clone with auto choke release or the cns carb with the separate choke cable. I might be able to give you a starting point for jetting if I know the elevation and average temp. where you live.
 
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