I don't know if this happens to all, but It often happens to me. If I have a problem that is quite obvious, something else, often completely unrelated happen at the same time, which of course one has very few reasons to look for.
Last weekend, my flywheel came loose. The bike ran perfect as it has been doing for quite some time, until it loosed power and stopped. I suspected the flywheel. Took the cover off and the nut, and surely it came loose shaving off the key and all.
As señor Brian Kirby suggested, I polished the tapered surface and tightened it in place with a little loctite on the cone.
Went riding today. The bike started easily but ran like crap with no idle and a hit and go powerband I didn't recognized at all. Things got worse and it revved like crazy, and finally stopped after only one lap. I thought of course that the flywheel came loose again but I hadn't.
The base gasket had been blown out and the entire part under the carb was lying on top of the gearbox under the intake.
So, the base gasket broke at the same time as my flywheel came loose last weekend. It doesn't make much sense to me. I did not notice any odd back fireing in the case or nothing of that kind.
I have had this happen to me, several times.. I call them life's little wake up call's.. When anything goes wrong that is out of the ordinary, I look to see if anything else is wrong too.. A couple of years ago I was having a problem with the Bing carb and I took it off to clean it up and check it out and to my amazment there was a piece of plastic in the intake manifold. You know that one that fits on top of the slide that keeps the jet needle in place. I seem to remember that I had miss placed one a few month earlier and because I could not find it I assumed that it had bounced underneath something in the shop. but to my amazment there it was. Why it did not get sucked in is beyond me.. It could have done some real damage.
Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)
74'250 hare scrambler (project)
74' 1/2 440 maico
78' 440 maico
72' cr125 Husky (project)
93' RMx 250 suzuki
Did you re-set or check the timing when you torqued the flywheel?
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"We the willing, led by the unknowing, are doing the impossible, for the ungrateful. We have done so much, for so long, with so little, that we are now qualified to do almost anything, with nothing."
1972 Penton Berkshire 100
1983 Husqvarna 250 XC
2011 Jayco 31.5 RLDS
2009 Chevy 2500 HD Duramax
What you described can happen because of the timing change that occurred when the flywheel came loose. You got a fire that happened most likely too late and blew down through the transfer ports and blew out the base gasket, I have seen them blow out the seal behind the stator. Your head torque was probably a bit low as well.
SouthRider, yes, of course I did. 1,8 mm BTDC.
TedG, Ok, I can buy that explanation. Timing was late, but my head is
torqued exactly according to the specifications with my
quality and calibrated torque wrench.
The seal is perfectly seated though. Took everything off to
polish the cone.
I have had this happen to me, several times.. I call them life's little wake up call's.. When anything goes wrong that is out of the ordinary, I look to see if anything else is wrong too.. A couple of years ago I was having a problem with the Bing carb and I took it off to clean it up and check it out and to my amazment there was a piece of plastic in the intake manifold. You know that one that fits on top of the slide that keeps the jet needle in place. I seem to remember that I had miss placed one a few month earlier and because I could not find it I assumed that it had bounced underneath something in the shop. but to my amazment there it was. Why it did not get sucked in is beyond me.. It could have done some real damage.
Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)
74'250 hare scrambler (project)
74' 1/2 440 maico
78' 440 maico
72' cr125 Husky (project)
93' RMx 250 suzuki
Did you re-set or check the timing when you torqued the flywheel?
_____________________________________________________________________________________
"We the willing, led by the unknowing, are doing the impossible, for the ungrateful. We have done so much, for so long, with so little, that we are now qualified to do almost anything, with nothing."
1972 Penton Berkshire 100
1983 Husqvarna 250 XC
2011 Jayco 31.5 RLDS
2009 Chevy 2500 HD Duramax
What you described can happen because of the timing change that occurred when the flywheel came loose. You got a fire that happened most likely too late and blew down through the transfer ports and blew out the base gasket, I have seen them blow out the seal behind the stator. Your head torque was probably a bit low as well.
SouthRider, yes, of course I did. 1,8 mm BTDC.
TedG, Ok, I can buy that explanation. Timing was late, but my head is
torqued exactly according to the specifications with my
quality and calibrated torque wrench.
The seal is perfectly seated though. Took everything off to
polish the cone.