3.3 will not stay running

[Jacks9930]

Ok I have just rebuilt a traxxas 3.3 engine with a new piston and sleeve. I have done many before with no issues. Everything else looks fine. I can get it started no problem but as soon as I take the heat off the glow plug it stalls. I have tried adjusting the high speed needle and the low speed needle. There is a new glow plug in (MC-8). With heat on the plug the engine run great, the idle needle is set at the point where the clutch is just about to engage. As I give it gas there is no hesitation with lots of power. Take the heat off and she dies after a second. Any suggestions?

 

[SchrodeMode]

What fuel are you using, how old?

 

[Jacks9930]

New jug of 20% backyard basher (Morgan Fuel)

 

[SchrodeMode]

Hopefully someone else with more tuning can help, I've only run "hot" plugs when using 20%. Did you make sure the shim was still on the head, also that the piston was facing the right way?

 

[Jacks9930]

that is a yes to both.

 

[Metalhead Matt]

I'd try another plug first. Did you seal the engine?

 

[Jacks9930]

Yes I seal the motor. Should I go hotter or colder than an 8.

 

[SchrodeMode]

I would go hotter, the smaller blocks don't retain the heat as much as a big block and it will also help with the lower nitro %

 

[Jacks9930]

well guys thanks for the help, I got it running. This was the first piston and sleeve I have bought from Ebay and it didn't have a Traxxas tag on it. All is good now.