Crucial 5ive B

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dougstar said:
Question? How tight where y head bolts?
Is your flywheel still good on the key?
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I had just retorqued the head, insulator, and carb after 1st run after re-installing the head and gasket. Just don't think I tightened the spark plug back down.?

Flywheel appears to looks good on the key. It's not loose. I guess I could pull it off and check. I'll take it off tomorrow and report back.
 
crucialRC said:
I had just retorqued the head, insulator, and carb after 1st run after re-installing the head and gasket. Just don't think I tightened the spark plug back down.?

Flywheel appears to looks good on the key. It's not loose. I guess I could pull it off and check. I'll take it off tomorrow and report back.
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Also ,how is the rod bearing?

One time ,I had a needle bearing pop out on a weed eater engine ,it destroy everything in its path all the way up to
the top end!
 
cbaker65 said:
Also ,how is the rod bearing?

One time ,I had a needle bearing pop out on a weed eater engine ,it destroy everything in its path all the way up to
the top end!
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Not sure. I will see the little end when I pull the piston off. Really didn't want to go all the way to the crank to look for failure but I guess I could. Nothing seems loose on the cranks side. At least nothing seems too far out.
 
The bearing didnt go. That's a lean run condition look at all the transfer and scoring on the exhaust side. I cant say for sure the plug being loose caused it but I would have thought you would have noticed it not running right. But it's a possibility.
pistons are designed to take cold air on a hot top. Happens all the time and doesn't cause an issue in a well designed engine. And detonation could be a cause, but as he didnt do anything to the timing, or jump the compression up I would doubt that as well. Normally when a key goes it's from a hard impact and the engine wont run. As ib6e said before I have a bunch of 2 strokes that don't run a key. Just relay on the interference fit of the taper on the crank and flywheel. So even with out the key in place you would have to have the flywheel rather loose or jar the hell out of the engine to throw the timing off that much. And again you should have noticed very poor engine performance.
Did you have the carb set like normal? I have a ton of top ends in my trash box that look just like that. Most have come from either no oil in the gas mix or some one who messed with the carb before dropping it off.(please don't take offense I know this isnt your first rodeo)
The other thought would be an Intake leak developing but again you should have noticed the thing lean out like crazy.
Just a few thoughts
 
crucialRC said:
Not sure. I will see the little end when I pull the piston off. Really didn't want to go all the way to the crank to look for failure but I guess I could. Nothing seems loose on the cranks side. At least nothing seems too far out.
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Guttted for you mate but you are gonna have to open the case up to clean it out??
 
gutted for you bud. this is not the post I was expecting to see from you. I was hoping all your issues would be sorted.

do you have a photo of the plug. does it look like it was running lean?

as mentioned above, I cant help thinking this was a lean tune as anything else you would have noticed running issues. such as idle raising poor performance.
 
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Seandonato73 said:
The bearing didnt go. That's a lean run condition look at all the transfer and scoring on the exhaust side. I cant say for sure the plug being loose caused it but I would have thought you would have noticed it not running right. But it's a possibility.
pistons are designed to take cold air on a hot top. Happens all the time and doesn't cause an issue in a well designed engine. And detonation could be a cause, but as he didnt do anything to the timing, or jump the compression up I would doubt that as well. Normally when a key goes it's from a hard impact and the engine wont run. As ib6e said before I have a bunch of 2 strokes that don't run a key. Just relay on the interference fit of the taper on the crank and flywheel. So even with out the key in place you would have to have the flywheel rather loose or jar the hell out of the engine to throw the timing off that much. And again you should have noticed very poor engine performance.
Did you have the carb set like normal? I have a ton of top ends in my trash box that look just like that. Most have come from either no oil in the gas mix or some one who messed with the carb before dropping it off.(please don't take offense I know this isnt your first rodeo)
The other thought would be an Intake leak developing but again you should have noticed the thing lean out like crazy.
Just a few thoughts
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I will post a video of it running. The only thing I noticed before the kaboom was that it was hard to start, which you will see in the video. Last time it was 5 slow pulls then 11 hard pulls. I don't think the idle was bad until near the end. Plug shows lean, but again didn't sound bad. Just a bog on low acceleration. High seamed good and even saw some smoke. Still think it had to do with the last time she kept leaning out because the bulb wouldn't stay full. Hmm, last gallon I think I added oil to the gas can???? With Klotz Benol, really cant tell since same color as gas.
mark35 said:
Guttted for you mate but you are gonna have to open the case up to clean it out??
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Yeah I was thinking either that or take her outside and spray out with WD40 then a 2stroke oil bath.
jimbo1 said:
gutted for you bud. this is not the post I was expecting to see from you. I was hoping all your issues would be sorted.

do you have a photo of the plug. does it look like it was running lean?

as mentioned above, I cant help thinking this was a lean tune as anything else you would have noticed running issues. such as idle raising poor performance.
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?Sorry to let you down Jimbo.?
1569353481353583724286579662056.jpg
 
crucialRC said:
Yeah I was thinking either that or take her outside and spray out with WD40 then a 2stroke oil bath.
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Don't, you can't get everything that way, pull it apart and see if there's any more damage done, don't risk your new head and such (if your going to replace the head) over a couple hour tear down!! Maybe the oil seal was leaking or something and pulling in air ?
 
Z.hb71 said:
why is there oil on that seal in the last picture? should be completely dry. other than that it looks fine, hows the gaskets? inspect for leaks and check if the case is cracked (doubt it, never seen one crack but just to be sure.
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PB Blaster to get the flywheel off. It didn't want to come off the crank. Almost broke my puller.
 
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