about to throw this in the fire

[afraz1er]

62t crank, stator, lightened flywheel
64v ported cases
61x cylinder ported by tim tynan
running 65u pistons at 84mm
protec c2 head with new 38cc domes
single 44sbn
new rings, gaskets through out, crank seals, and orings in head
protec pipe
h20 designs waterbox
stator is a new reman from sbt

currently running 87.5 low, 155 high, 115 gram spring, 1.5 needle and seat
5/8 out on the low, 7/8 out on the high

seems to start and idle fine, just cant get it to take any throttle. i had a 2.0n/s, 120 low, 150 high, dull spring before with no change. yesterday i replaced the ignition coil.

anyone have any ideas as to what the problem could be? any help would be appreciated.

 

[afraz1er]

apparently im not special enough to upload directly to the site, so here is a short youtube video of the problem.

 

[Quinc]

Your Pilot jet is way to small. You need at least a 125 or 130 Pilot. You also probably need to go to a 2.0 or 2.3 seat. Best bet would be to call Carl at protec or call Tim.

Edit: Also do a leak down test.

 

[afraz1er]

Your Pilot jet is way to small. You need at least a 125 or 130 Pilot. You also probably need to go to a 2.0 or 2.3 seat. Best bet would be to call Carl at protec or call Tim.

Edit: Also do a leak down test.

I had a 120 in before(ran the same) pretty sure I have a 130 here and I'll try that. Went to the smaller jet based on some settings I found from factory pipe for a 750sx. I have a 2.0 n/s here, and springs. What spring would you suggest, or popoff?

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[Quinc]

It all depends on which pipe you have. A stock 701 Superjet with 44sbn carb runs a 120 Pilot... Start with your pop off around 24psi then try 18psi if it gets better lower psi some more. If it gets worse try 25psi.

 

[bored&stroked]

Man thats a small carb for that application, but that should give great throttle response. My 61x w/ protec pipe and single 44sbn runs the standerd 120L 150H or somewhere in that area [give or take a jet size]. Check for crankcase leaks, make sure your sparkplug wires are in the caps correctly, then check the carb over very carefully.

 

[eastcoastjumper]

Throw that sbt stator in the fire, get a used oem from jetmaniac, and go back to your 120/150 jetting.

 

[afraz1er]

Talked to a buddy of mine today who is a Powersports instructor at the local college. Based on the video he thinks the crankshaft is out of phase.

I'll try these suggestions, then check the crank when he gets back in town next week and report back.

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[Harbor]

I guess if I had that here I'd check the ignition timing with a light. I use a degree wheel and a pointer, positive piston stop or TDC indicator to find true TDC... Mark the flywheel near my cut cover indicator, install msd timing tape and the cut front cover. Read ignition timing with a timing light.

I checked another members timing, his engine would backfire out the pipe but wouldn't start. It was an eBay rebuilt or new stator, I found the cranking timing was 60 degree retarded... Installed my stator and bam engine fired and nearly fell of the bench lol....

My 02

 

[afraz1er]

I guess if I had that here I'd check the ignition timing with a light. I use a degree wheel and a pointer, positive piston stop or TDC indicator to find true TDC... Mark the flywheel near my cut cover indicator, install msd timing tape and the cut front cover. Read ignition timing with a timing light.

I checked another members timing, his engine would backfire out the pipe but wouldn't start. It was an eBay rebuilt or new stator, I found the cranking timing was 60 degree retarded... Installed my stator and bam engine fired and nearly fell of the bench lol....

My 02

Do you have a pic of your cut front cover ?

I started with an msd Enhancer and was getting an occasional backfire on start up. Happened three times, third time it blew up the waterbox. Put the stock cdi in and no more back fires. Still ran the same though as in the video.

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[Harbor]

My preference was the long eared cover, I'd make the end of the ear corispond to my TDC mark I'd make on the flywheel and be my fixed indicator.

Another thing I'd be looking at visually is spark quality and quantity during the event. You could remove a plug boot and hold it off the spark plug slightly to watch the spark and see what it does if anything.. Make sure it sparking and not going away...

Also the carb is capable of flowing fuel thru all circuits, not just the idle circuit.

With a positive stop and degree wheel you can check crank phase. Wheels got to be small if engine is in ski, this one rubs hull slighty so can be any bigger... It a 7inch wheel.....