I need help jetting my Blaster

[Quadrrider2010]

I just recently bought my 2nd Blaster and rebuilt it. It has 120 psi for compression, fresh gas, carb clean, full fmf system with powercore 2 silencer, stock carb. I am at an elevation of 682’ currently running a 270 main and a 32.5 pilot. Still doesn’t run right did a leak down test and everything was good. Not the greatest at jetting carbs or anything thing like that I’m 14 and just got into working on my quads. So any suggestions would definitely help. spits and sputters around a quarter throttle also has good spark

 

[Quadrrider2010]

Update: changed the jet to a 320 currently will run but only on the choke did the same with a 300 so bumped it up but with choke off on the 320 it sorta sounds like it’s backfiring but I’m not completely sure

 

[Quadrrider2010]

Also the spark plug is wet and a sort of a brown color

 

[RIDE-RED350r]

Sounds like you are rich on the main. Stock spec calls for a 230 main and your 270 you initially had may have been a bit rich to behind with and then jumping up into the 300s made it worse. I would try a 260 and look for improvement. If still underpowered then a 250. Always check your plug and be wary of signs of it being too lean. A lean condition is evident by a smooth loss of power where too rich will be a similar loss of power but will almost sound like the engine is drowning itself and will put out excessive smoke.

 

[Quadrrider2010]

Sounds like you are rich on the main. Stock spec calls for a 230 main and your 270 you initially had may have been a bit rich to behind with and then jumping up into the 300s made it worse. I would try a 260 and look for improvement. If still underpowered then a 250. Always check your plug and be wary of signs of it being too lean. A lean condition is evident by a smooth loss of power where too rich will be a similar loss of power but will almost sound like the engine is drowning itself and will put out excessive smoke.

Ok thanks will have to try that tommorrow after school

 

[Quadrrider2010]

So I threw a 260 in and it fired up and idled. significantly helped with power but after a few minutes it got super hot and the pipe was glowing red hot. The spark plug is a BR8EG

 

[acdiez]

Strange, that points to a lean condition typically or timing. 260-270 main does sound right to me, perhaps take the stator cover off and check the flywheel. Make sure it is tight and the woodruff key is still in place on the crank. ANY play at all (flywheel to crankshaft) is a no go, but pay attention because these engines are so small you will probably be able to wiggle the crank back and forth. Make sure if the crank wiggles, the flywheel wiggles with it.

 

[RIDE-RED350r]

Yeah, the mods you have shouldn't require much more than 2 or 3 steps richer on the main, and likely little to no change on the pilot jet.

Along with checking your flywheel for a sheared key, also check the exhaust and make sure it's not obstructed. Usually by the time a 2-stroke pipe is glowing red hot, major engine damage is done. But an obstructed pipe and/or silencer can definitely cause that as well even if the jetting is safe. It needs to breathe

 

[Quadrrider2010]

Yeah, the mods you have shouldn't require much more than 2 or 3 steps richer on the main, and likely little to no change on the pilot jet.

Along with checking your flywheel for a sheared key, also check the exhaust and make sure it's not obstructed. Usually by the time a 2-stroke pipe is glowing red hot, major engine damage is done. But an obstructed pipe and/or silencer can definitely cause that as well even if the jetting is safe. It needs to breathe

All the exhaust mods are brand new I’m not sure how they could be obstructed but will check

 

[RIDE-RED350r]

All the exhaust mods are brand new I’m not sure how they could be obstructed but will check

If new then I'm sure they are fine. Wasn't sure if they were new or on it when you got the quad.

 

[Quadrrider2010]

Alright so I threw a 270 main back in because the spark plug showed that the quad was running lean with the 260 and the pipe still glowed red after about a minute. I noticed when I stopped that the base gasket up in the front right under where the exhaust flange mounts up there were some type of bubbles coming out not sure if it was coming from the pipe or leaking from the base gasket if that means anything I’m not sure

 

[RIDE-RED350r]

There should be no air leaks at the base gasket.