Help! Wont start

[88yamahablaster]

I have an 88 blaster.... Rings blew last year... Rebuilt top end.... Rebuilt carb.... Eliminated tors system... New plug( the specific one it calls for)....compression test is good... It def gets spark....new flywheel.... New stator.....still nothin..... I have even pulled the throttle off the carb and dripped gas directly into the carb from above and it DID kick over and ran for a few seconds ...... The bowl
Of the carb fills with gas..... Why will it not spray up???esp with the rebuild... Oh yea new reeds to... They are functioning or the gas drip from above woulnd have gottin tot he spark.... The carb was rebuilt and every hole allows carb cleaner through it..... Losing my mind over here!!!!!!!!!!!!!

 

[Blaaster]

How are the reeds.

Have you done a leak test?

 

[Herpderplol]

have you used an actual spark TESTER?

they have a larger gap to replicate the amount of power needed to spark under compression.

 

[Larry's Shee]

Specifics of compression test? (lbs) Did you remove emulsion tube when cleaning? Can you see through main and pilot jet? Sure pilot jet passage is open? Double check float level.

 

[88yamahablaster]

Compression was 130psi....wouldnt it fail if there was a leak?? The reeds are functioning .... I dripped gas thru the top of the carb( without throttle as if it was wide open).... Only spark test was plug innthe boot and bottom against the frame ( nice blue spark) it was also strong enough to ignite the fuel that was dripped in from above..... It seems like the bowl is not getting pressure to push the fuel up.? But it was just rebuilt and every hole is clear( woth the choke open- the one brass tube (not the over flow one) is closed when the choke is and opened when the choke is.... Every hole allowed fluid thru it

 

[Awk08]

Flywheel woodruff key present and aligning flywheel with crank groove ?
It can be sparking, just not at the correct time in the cycle

 

[tbrooks]

The amount of gas entering the carb from the bowl is dependent on the float height. Compression and leak tests are 2 different animals, you can have great compression with a bad airleak, the most common air leak is at the carb boot which would have absolutely nothing to do with engine compression, but you could still have leaks elswhere

 

[88yamahablaster]

Ok i wasnt sure about the corrolation of the compression and the leak test....the bowl fills with fuel tho... So the rubber boot the carb slides into between the carb and the reeds may be leaking?? Will a new clamp fix that or should i just replace it... I kn the compression of the motor opens the reeds... Does it also pressurize the carb to spray the gas up from the bowl ?

 

[88yamahablaster]

Yea the flywheel has a key on the crank that it had to line up with to slide on... And the stator only has two bolts and was installed the same direction as the stock one that it replaced

 

[jus_me]

The carb works off of a vacuum and the cyl sucks the fuel through, it doesn't actually build pressure and spray. Are you hitting the throttle when you try and start it? you said you deleted the tors, did you do the idle screw in the carb or just deleted it electronically?

Is piston in correctly? No obstructions in the exhaust like a critter nest?

 

[Larry's Shee]

Really is best to blow compressed air through passages to ensure cleanliness. Did you take pilot and main jet out and actually look through them? Emulsion tube is what the main screws into and comes out through slide area. I've had to drive them out if carb is really bad. That's the beauty of carb dip, they can soak as long as needed.

 

[tbrooks]

Ok i wasnt sure about the corrolation of the compression and the leak test....the bowl fills with fuel tho... So the rubber boot the carb slides into between the carb and the reeds may be leaking?? Will a new clamp fix that or should i just replace it... I kn the compression of the motor opens the reeds... Does it also pressurize the carb to spray the gas up from the bowl ?

Just because the bowl fills with fuel, it doesn't mean the floats are correct the must be measured and set correctly in order for proper performance. A mm out of range either way can cause issues. Yes, that boot, they normally leak at the connection to the reed valve, and it is recommended to use some rtv there. However this is not definite and you can still have leaks elsewhere, leak testing is a must and cannot be skipped. The engine must be able to hold about 7 psi for at least 5 minutes to run safely