1977 mariner inline HELP

I HAVE A INLINE 115 THAT HAS B

I HAVE A INLINE 115 THAT HAS BEEN REBUILT WITH ONE CYLINDER BORED OVER..THE MOTOR SEEMS LIKE ITS BEEN HARD STARTING SINCE DAY ONE.ONCE IT STARTS IT RUNS FINE UNLESS I LET IT SIT FOR MORE THAN 30MIN THEN I HAVE TO LEAN ON THE STARTER AND CHOKE TO GET IT TO RUN THEN ITS FINE.I RAN 3 TANKS OF FUEL THREW IT NOT GOING OVER 3500 TO BREAK IT IN PROPERLY TOOKE IT UP TO 4000+THI WEEKED AND IT RAN FINE FOR A LITTLE BIT THEN IT STARTED TO MISS FIRE AND BOG DOWN AND I COULDNT GET IT OVER 2000 RPM...RAN STRONG ??????

"most two strokes will need ch

"most two strokes will need choke to start from cold, half hour is usually enough for engine to cool dramatically. are you running 50:1 fuel mix? check plugs for hot spots or white looking electrodes you may be leaning out a cylinder, check all three carbs for proper operation, remember if one of the carbs is playing up it will lean out 2 cylinders and no fuel to cylinders also means no OIL and that is bad news.

i would change all plugs and go from there if it continues to misfire and or bog down it may be getting hot ie lack of lubrication in cylinders or engine timing is incorrect cause pre-igntiton detonation which can cause engine temp to increase and foul plugs."