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jetmechG550
RCTalk VIP
Sounds like it's worn, how much fuel has been through it and what temps have you been running. There are compression gauges out there, not sure how much they run though. If the flywheel turns really easy when it's warm then chances are she's on it's last legs.
- Thread starter
- #3
i don't know how much fuel has been run through it, I bought it used from a buddy that didn't know alot about them and didn't know how to tune thats why i got it so cheap ($300) as for the temp its been running around 260-270 but i think its compression cause it starts and runs fine till u get it warmed up and kill it
Another way to get a general idea is how easy it is to turn the flywheel cold. Typically, as you turn the flywheel and the piston head toward TDC, it's feel tight and be harder to turn. Once you hit TDC and start on the downstroke, you'll hear a 'pop', kind of like the old finger-in-the cheek sound.
If you can spin the flywheel easy on a cold mill, chances are that P/S are done for and you can either replace them or just buy a new mill.
Hope it helps!
If you can spin the flywheel easy on a cold mill, chances are that P/S are done for and you can either replace them or just buy a new mill.
Hope it helps!
Can you turn the engine over easily with your finger on the flywheel when it's cold? I've heard that's a way to tell... but I could do that with my OS 21 RG for 4 gallons before it started running bad and I had it pinched. Maybe I overestimate my paw strength...
When it warms up, does it not stay running? Mine started flaming out for no apparent reason and seemed like it wouldn't hold a tune or wouldn't tune. But again, that was my OS. It's the only engine I've ever run that much fuel through before getting rid of it. I still have it, in my buggy. It had 11-12 gallons on it when I had it re-pinched. It has 3 on it since then.
When it warms up, does it not stay running? Mine started flaming out for no apparent reason and seemed like it wouldn't hold a tune or wouldn't tune. But again, that was my OS. It's the only engine I've ever run that much fuel through before getting rid of it. I still have it, in my buggy. It had 11-12 gallons on it when I had it re-pinched. It has 3 on it since then.
Not hard, but the question is, is it worth it. You may want to price a new P/S before going down that road, as it may make better sense to just get a new mill.
jetmechG550
RCTalk VIP
New P/S for a 2.5R can run about $50, engine exchange program can run about $100 and about $135 for a 3.3R. I suggested checking compression hot just because I have seen a few mills that seemed decent cold but once they warmed up were very, very loose.
MW is right... typically, if enough fuel has run through the engine to wear out the piston/sleeve, the con-rod is the next thing to fail, then the main bearings.
If anything, I'd get the piston/sleeve pinched and get a new 3.3 on order. Getting a pinch done is only about $20. That way you don't spend a lot to have an engine with old bearings and a con-rod. But you still can get a few more gallons through it before it's totally dead and needs a complete rebuild.
If anything, I'd get the piston/sleeve pinched and get a new 3.3 on order. Getting a pinch done is only about $20. That way you don't spend a lot to have an engine with old bearings and a con-rod. But you still can get a few more gallons through it before it's totally dead and needs a complete rebuild.
SVORay
RCTalk Addict
olds97_lss said:
That sound exactly like my 2.5r
onder2: Tunning has become almost impossible to maintain and she dies with no appraent reason either. The temp is the weird part....I'll get her to 220 and make a few rounds with her. then she comes back running 170-190's ??? I've run 3 tanks through her just trying to tune the dang thing. I ca't wait to get my OS .18TM installed
- Thread starter
- #13
i got the new mill all broke in but my temps are still way up (270-330) my hsn is set at 4 1/2 and i've cut the windshield i don't know what the problem is and on top of that its like 40 degrees outside
jetmechG550
RCTalk VIP
Check for an airleak. First place to check is the fuel tank o-ring. The blue one's are notorious for going bad and causing high temps. If that's good, spray the mill at the carb base, backplate under the head, etc with WD-40, if it dies at one of those spots, there's your leak.
SVORay
RCTalk Addict
l2evo said:
The cold could be effecting it's tune as well. It's hit or miss with mine when the temp drops down around here. There is sometimes it's a pice of cake while other times it want tune. Also try running it at 4 turns.
