Hello/New Double Blaster owner

[tibblits]

Hello everyone. Name's Stephen, I'm new to Blasters and 2 strokes in general. Traded my 2023 GPX MXR125cc pit bike and a .223 upper for these two blasters The green one was running good (so I thought) and the white one came with everything to get running I believe (the engine is out of it) but needs a bottom end rebuild, so I was told. I took the green one out shed hunting yesterday and when I was coming back in it started losing power quite noticeably and eventually died by the truck and I have not been able to start it since. It's getting spark and I checked the compression but it only put up about 35-40psi I'm guessing I fried the piston rings? I was 6th gear wide open for a bit right before this so maybe that has something to do with it but I would think you should be able to run these things however you want to without f*cking them up. I will say even tho it sounded like it ran really good it definitely didn't idle and there's no ignition hooked up with this one so it was just kick start and go lol and then it would die when you come to a stop. But it had tons of power and was an absolute blast so I'd like to get it running again but it sounds like from what I've been reading that maybe it wasn't tuned correctly because it should hold an idle. It never smoked or anything when it ran but I'd have to sit there and bump the throttle to keep it running if I was just sitting. Anyway I'm open to any and all suggestions you guys can give me as to why this happened because I don't want to rebuild it only for it to happen again. I don't know sh*t about 2 strokes but I'm semi mechanically inclined and don't have a budget for these things obviously I paid zero dollars for them lol but they are super sick so I'm willing to buy parts for them but not much else. Thanks y'all

 

[tibblits]

@RIDE-RED350r

 

[RIDE-RED350r]

Yeah, sounds like you have an air leak somewhere or a dirty carb that had you running lean. A property tuned and healthy 2-stroke should idle without a problem once up to temp.

When you dig into the topend, also fully disassemble and clean the carb. If it looks anything but clean and new inside, that will give you problems.

 

[tibblits]

Yeah, sounds like you have an air leak somewhere or a dirty carb that had you running lean. A property tuned and healthy 2-stroke should idle without a problem once up to temp.

When you dig into the topend, also fully disassemble and clean the carb. If it looks anything but clean and new inside, that will give you problems.

Sweet yeah it'll be a couple weeks before I can tear into it but I'm looking forward to becoming an expert on these things and get that white one up and running someday

 

[tibblits]

Ok so I was finally able to tear into the top end on the green party quad (yes that's what we call our quads around here ). Piston looks a little worn I'd say.

 

[RIDE-RED350r]

Yep, looks like a lean burn-down. Not normal wear and tear. Very likely that engine has an air leak somewhere.

 

[tibblits]

Yep, looks like a lean burn-down. Not normal wear and tear. Very likely that engine has an air leak somewhere.

Thanks.. that's what I figured. It's weird to me though because nothing seems out of the ordinary like all the gaskets looked good so not sure where the leak is coming from.

 

[RIDE-RED350r]

Crank seals, carb boot (dry rotted, cracked or just loose) cylinder base gasket and reed valve gaskets are the most common causes. Other less common cause could be a crack in the crankcase between the crankcase and transmission or other outside source of unregulated air can be taken in. But that's not very common. If all the top end gaskets appeared to be in good working order, crank seals would be my #1 suspect. But now that the top end is off you can't do a leak down test to verify/diagnose.

I'd figure on a full bottom-up rebuild myself. I had Ken O'Connor Racing rebuild the crank in my daughters Blaster over the winter. He did a great job, fast turnaround and very reasonably priced. I would highly recommend him if you choose to have the crankshaft rebuilt.

 

[tibblits]

Crank seals, carb boot (dry rotted, cracked or just loose) cylinder base gasket and reed valve gaskets are the most common causes. Other less common cause could be a crack in the crankcase between the crankcase and transmission or other outside source of unregulated air can be taken in. But that's not very common. If all the top end gaskets appeared to be in good working order, crank seals would be my #1 suspect. But now that the top end is off you can't do a leak down test to verify/diagnose.

I'd figure on a full bottom-up rebuild myself. I had Ken O'Connor Racing rebuild the crank in my daughters Blaster over the winter. He did a great job, fast turnaround and very reasonably priced. I would highly recommend him if you choose to have the crankshaft rebuilt.

How about if the port on the carb that used to be the oil supply was just a cut off hose would that be some of my problem? Just wondering.. I capped it anyways once I realized that's how it's supposed to be.

 

[RIDE-RED350r]

Yes, that would also be a source of unregulated air getting into the engine .

They could very well be your issue.

 

[RIDE-RED350r]

Have you ever replaced a top end in the past?? Particularly a 2-stroke??