Author Topic: OK PROBLEM STILL THERE HOW TO SET TIMING AND JET SIZES  (Read 3822 times)

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montynut

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Re: OK PROBLEM STILL THERE HOW TO SET TIMING AND JET SIZES
« Reply #15 on: September 19, 2008, 11:23:43 pm »
Sounds like big end rollers welded together from heat which gives very little free play but lots and lots of heat. This may have been caused by the crank halves being off set causing the crank seals to open up when engine speed rises. This was a problem a friend of mine suffered with a new VA360 (crank shaft clutch version) all those years ago. It was suggested at the time that the problem was caused by the clutch arrangement, but then everything that went wrong with that model (it was probably the least succesful of the early '70's Monties) was blamed on that clutc arrangement.

Offline cappra

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Re: OK PROBLEM STILL THERE HOW TO SET TIMING AND JET SIZES
« Reply #16 on: September 20, 2008, 08:37:31 pm »
One of the main problems with the early 360 VA's was the bad
casting of the cases.  It was so bad that in no time at all the transmission
bearings would be loose so to cause problems with transmission.  I just got
done trying to rebuild an early model and the trans bearing fit so loose in the cases,
that you could move the trans shafts a good 3-4mm back and forth!  I then used a pair
of nos cases and noticed that the selector shaft hole had a bronze sleeve to help with
this problem.  The main bearings were also loose and just dropped out on their own.
So, now I'm not so sure that the crank mounted clutch was the cause of any of the reported
problems.  When Montesa reverted to the clutch mounted on the primary shaft, the cases
were die forged and not the sand casted earlier ones.  Now the 76 VA 360 early model is one
of the most collectable of all Montesa's out there!  I have seen original examples go for well
over 5 thousand (USD) to collectors in Spain.