yamaha g1 hesitates from idle

[jlsk8ter]

my g1 has new piston, rings and crankcase seals, fuel and air filters and spark plug.also cleaned the carb and fuel pump.the muffle was barbecued twice as well. the problem is i have to pump the gas for it to get going from a dead stop,if i just floor it the motor just turns over, but once i do get going it runs perfect. ive tried to adjust the pilot screw and throttle stop to factory specs but it doesn't seem to help at all. if i just slightly pull the choke out, it takes off from a stop instantly. any tips ?

[GMB74]

Sounds like you still have a plugged jet or passage in the carburetor. Ethanol fuel causes corrosion in carburetors which can restrict or even plug off the air and fuel passages. Completely disassemble your carb and clean it with spray carb cleaner. Run a fine wire through the jets to remove any deposits that may restrict them. Use a nozzle on the spray can to spray through the passages to be sure they are clear. Wear eye protection when doing this! It is common to have the spray blow back into your face.

[jlsk8ter]

thats what i did just 2 days ago, i ook it completely apart and did everything. is there a jet i need to focus on ? i did the main one in the middle, the one to the side of that and the one on the outside of the carb, i even cleaned the float and needle. should i remove the pilot screw and clean in thee ? thats the only thing i didn't do on the carb

[GMB74]

Yes, especially those passages. Spray into the passages and make sure the spray comes out the tiny holes in the carb where the throttle butterfly rests at idle. That is where your fuel comes from at low RPM's, such as on startup.
While you have the carb off, check the intake for air leaks. Check the boot the carb attaches to for cracks and leaks. If yours has a boost bottle style intake, check it for cracks and leaking hoses.
If you still have problems,check your throttle linkages. As you slowly depress the gas pedal, the start switch should close and the engine should start to crank. The throttle should still be closed and at idle. Push a little more and the throttle should begin to open. If the idle speed is set too low, or if the throttle opens too soon the engine will start hard.

[jlsk8ter]

GMB74, i cleaned the carb again and checked the jets and passages like you said. no blockage at all.i tested my compression and its only 105-110, isnt that low for being rebuilt ? i got a few says riding time on it so im guessing the rings are seated by now. also there is a small exhaust leak coming from the muffler where it meets the manifold/exhaust butterfly. would that cause lower than normal compression ?

[GMB74]

An exhaust leak would not alter compression readings. Your readings are a tad low for a rebuilt engine, but your rings may not be fully seated or the guage could read low. I don't see this as being an issue. You state it takes right off if you give it a little choke, but without the choke it sits and cranks without starting. This tells me the engine is not getting enough gas (lean mixture) to start. Questions I have for you: What is your ambient temperature? These buggies were designed to run on pure gasoline. Ethanol gas tends to lean out the fuel mixture. If it is cool out, it may be jetted too lean. Does it start any better with the engine fully warmed up?
When the crankshaft oil seals were done, were you careful to reset the timing plate exactly where it was before you took it off. Perhaps you changed the timing slightly which would make it start harder. The timing can be checked with a timing light if you have one available.

[jlsk8ter]

temps have been from 55-65 last few days. if i pump the gas a bit it takes off without any choke or if i floor it it will take off after turning over 5 or so secs. it doesn't matter if its warmed up or not, does the same thing. i have a timing gun. how do i do it on a cart ? thanks

[jlsk8ter]

its definitely not the carb or pilot jet. i went though it for the 3rd time and cleaned the jets again with compressed air and wire. what should i test from here ? i found a how to on the timing and it says "Direct the timing light to the "view port" in the fan cover and observe whether the timing mark on the outer end of the fan vane aligns with the mark on the crankcase" where is the view port on the fan cover ? i need a more detailed write up on timing the g1.

[jlsk8ter]

timing is spot on, where can i go from here ?