BeenThere

I have a bit of a problem.
I bought a 15 CV-X a couple of years ago. When I got home, I lubed it up and put it on the shelf until I needed it.
This week, I finally got around to using it. It has nice compression but took a while to find the original carb settings.
I broke it in by running it around a parking lot for a half tank on the rich side, letting it cool and then repeating. I did this to heat cycle it for 5 tanks going leaner each time but staying on the rich side of peak. I was careful to vary the speed throughout this period from idle to full speed for short periods.
The problem is, on the 10th cycle (last half of the 5th tank) it suddenly started to rattle and became very sluggish. I stopped at this point and cooled it down with the piston at BDC.
I opened the rear adapter plate and found two things of interest.
1) the crankcase has a small piece of metal missing on the inside. The adapter plate has a small flat spot for clearance of the piston. On the inside of the crankcase, just above this spot, there is a 1mm x2mm irregular shaped chip missing. I am not too concerned about this as there were no metal fragments at all and the sleeve seems fine. There is no sign of any damage at all and the engine stills has excellent compression.
2) Of more concern is the cause of the rattle. The starting shaft now has some play (in and out).
With the engine fully assembled, the starter shaft moves in and out about 0.6mm. As the crank rotates this shaft, it rattles. Should there be that much play between the disk on the starter shaft and the back of the adapter plate? The bushing in the adapter plate seems fine but it's as if this bushing has slipped outward by this margin.
One thing I should note. I, long ago took the pull starters off all my cars (bad elbow) and simply use a one way bearing in a socket attached to a cordless drill (being careful to only use drills that spin more or less the speed that the pull starter would spin it) or bump start it if I remembered to charge the batteries.
Your advise on this problem would be appreciated.

BeenThere (done that, Got the tee shirt)

Bax

My Feedback: (11)

There will be some rattle. The starter plate/shaft 'floats' in the rear cover. It will move around a bit. To prevent the noise, you should be using a fuel that contains more oil in the oil mix. O.S. states that your fuel should have 18% oil content. Many so-called 'RC Car" fuels have 12%-14%. The oil provides a cushion for the starting plate. We like to see a good portion of the fuel's oil content be castor oil. That's just about the best oil your engine can have, though it's messier than the sythetic oils that are commonly-used.

BeenThere

Thanks for the fast reply.
I'll try a different fuel.
Would it do any harm if I try to use a brass shim to take up some of this play?
Also, any thoughts on the chip in the crankcase?

Bax

My Feedback: (11)

I don't believe that's a 'chip'. If you look carefully, it where the case got machined by one of the transfer ports. That 'notch' is common for that engine. If an actual metal chip had gone through the engine, it would have destroyed the piston/liner fit, and hammered the inside of the cylinder head.

BeenThere

I thought it was something like that.
Thanks again for the fast reply.
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