Older 7.5 cc inboard intake question

[Jeff Baggett]

This did not answer my question, I know how to line up the casting, but there is a disc or wheel inside that allows fuel to come in. and it is lined up witht the crank. The question is which part in the disk does the crank pin go in to, and why am I getting "output" from the carb when the engine is running, I think the disc is set up wrong.

[MECOA]

There should be 2 places the crank pin can locate on the disk. This is so the engine can run either direction.

If you are getting output or blowby back through the carb then the valve is not sealing properly or the piston cylinder fit is no good.

http://mecoa.com/faq/crankshafts/blowby.htm

If the engine is running the correct direction at higher speeds the valve is in the position. You can kind of thak this info to determin which way the valve is set to run.

http://mecoa.com/faq/crankshafts/crankr ... /crank.htm

Intake is intake, front or rear. just turn the crank and compare the opening to the one shown. Hope this helps.

[orb_dharma]

There should be 2 places the crank pin can locate on the disk. This is so the engine can run either direction.

If you are getting output or blowby back through the carb then the valve is not sealing properly or the piston cylinder fit is no good.

http://mecoa.com/faq/crankshafts/blowby.htm

If the engine is running the correct direction at higher speeds the valve is in the position. You can kind of thak this info to determin which way the valve is set to run.

http://mecoa.com/faq/crankshafts/crankr ... /crank.htm

Intake is intake, front or rear. just turn the crank and compare the opening to the one shown. Hope this helps.

As previously explained, needs clarification , In the normal upright position with the carb removed and rear rotary valve seen open, should the piston be positioned at TDC(Top) or BDC(Bottom)? Thanks

[MECOA]

as shown on this page
http://mecoa.com/faq/crankshafts/crankr ... /crank.htm

all are YDC but the rear valve is shown off TDC slightly.

Please read it carefully.