Project Vento has begun: help wanted.

[cooperplace]

Ok thanks, good to know. it jumps 8mm easily. Now I just need to find some fuel hose clamps that work properly. Got some coming.

[cooperplace]

Took the 900 S2 for a ride yesterday. It didn't break down until I got home, when the sprag clutch died again. It was only replaced about 200km ago. Thank god the Vento doesn't have electric start.

[Jordan]

Ok thanks, good to know. it jumps 8mm easily. Now I just need to find some fuel hose clamps that work properly. Got some coming.

I knew a Lucas-trained magneto serviceman who had a test bench for magnetos.
He said that after each rebuild a magneto should be run for two hours with a spark gap visible, so it could get properly hot.
After that time the sparks should still be consistent.
I thought that was somewhat extreme and probably not necessary to have so long a test, but worth checking so I rigged up a test with a used magneto I bought at a swap meet.
Sure enough, all looked fine with a convincing shower of sparks until after about half an hour when it began to falter and got worse.

[Duccout]

'Took the 900 S2 for a ride yesterday. It didn't break down until I got home, when the sprag clutch died again. It was only replaced about 200km ago. Thank god the Vento doesn't have electric start.'

What happens to the sprag? Does it fail to grip the crankshaft to turn the engine over? Touch wood, I've had my S2 for 37 years and the sprag has never given trouble.

[cooperplace]

I don't know what happens to it, it breaks. The start button just gives a zinging noise.

[Buster]

After that time the sparks should still be consistent.
I thought that was somewhat extreme and probably not necessary to have so long a test, but worth checking so I rigged up a test with a used magneto I bought at a swap meet.
Sure enough, all looked fine with a convincing shower of sparks until after about half an hour when it began to falter and got worse.
If a magneto has been stored unused for a length of time it is likely that moisture has entered the windings. This causes the coating between the windings to break down in use. The mag will work ok to start with but as it warms up the insulation between windings breaks down and shorts out reducing the power of the spark.

[Jordan]

Another thing I heard can go wrong with coils, even new ones, is that they can expand when they get hot.
That causes internal open circuits, and these sometimes temporarily come good again when cooled.

[cooperplace]

Re my issue with difficulty in getting it onto the stand, I took it to the stand guy today, and he's going shorten the stand and add a curly bit of steel out the side, just like on my 900. Get it back next week.

[Duccout]

As regards the stand, I would check to see that the rear shocks are the right length, as obviously if someone has fitted shorter shocks then it will be a right old heave onto the stand.

Colin.

[cooperplace]

I fitted new rear shocks, and carefully checked to ensure they're the correct length, and the same length as the stock shocks. Nonetheless, it's a long way between the rear wheel and the ground.