I've put about 4 hours on my 77 RC gas since major rebuilding, including pistons and sleeves, bearings etc.  The engine sounds good and seems to have good power.  But I have trouble getting the starter to turn it over.  If it turns over, it does start right away.  

I have a new battery, new heavy cables, new starter switch. I'm keeping my 6v system.   I took the starter to a guy who replaced a &quot;bearing&quot; (bushing at the gear end, I think) and said the shaft was bent but he straightened it.  Also he turned down the armature.  

After that starter work, I can get it to crank over pretty well when the engine is cool, but not when it's hot. Either have it on a hill and coast, or come back later.

I tried a jumper cable from the battery positive to a starter mounting bolt, in case of bad ground of the dash. (It's positive ground, of course.) No help.  

Should I invest in a new/rebuilt starter?  Put another 15 hours on it? (But I'd really like to be able to start it with the starter when hot.)   Other ideas?

Thanks.

Tom Murray