Hi.

Remember I run 6 mm venturi and compared to the stock 8 mm, you´ve to turn the hsn 1/2 to 7/10 OUT.

My setting with 25% Byron are:
HSN 2 1/4 from fully closed
LSN 1 7/8 from fully closed

How many liters has it been running? You could try remove on of the 4 shims under the head. Perhaps your engine hasn´t got the same compression ratio as when it was just broken in :)

Thanks for your reply
Engine has burn out about 4-4.5 Galons
but when its on operation temp, compression is very weak maybe this is the answer to stop problem
But when i play harder and dont use the low rpms (about idle) engine works fine

Also my friend has got the same engine same amount of usage and the same problem

Are your engine still fine ? how many galons did you use ?

Or really this is a two galoon motor ? Because, in the beginning (about 10 litres) performans was very good

And i will try to remove one shim on it

Thanks

Hi.

Mine has 18 liters (4 3/4 gallons) on it. Still very good compression and no wear on the crank and conrod. BUT: I just got new bearings from AVID today. I can drag and push the flywheel too mush in and out (yes, the flywheel are mounted correct ;)) and a little side play from the front bearing.

Will report back, when I have changed them and run the engine again :)

EDIT: Made a meassurement on the crank "pin???": Still 4,99 - 5,00 mm horisontal and 4,98 - 4,99 mm vertical. If the P/S should wear out, it should still be cost efficient to buy a new P/S set. But no need for that right now :)

Bought AVID engine bearings (total $15 ;)). Interesting to see the durability of those bearings.

My engine are still performing very well. I removed one 0,2 mm shim. Set the idlespeed a little higher compared to when it was just broken in. 20,7 liter (5,5 gallons) through it until now.

OD77T plug, Novarossi 9901/41021 and Novarossi 6 mm venturi.

Pro star + 2090 pipe
 

I'am going to try this engine with 2090 pipe from os. Think this combo will work super