Mark VII motor belt
Posted: Wed Sep 23, 2015 11:06 am
I hate to open this can of worms again but....
Finally got the time to tear into my new (to me) mark VII. After a little (ok a lot) of spray contact cleaner / lube on the fwd, stop, rev switch, the motor ran fine in both directions.
How does the switch come apart? Does the back just pry off? I did not want to break anything.
Anyway, now the belt question. The belt that was on the machine was / is an original? SS Magna belt p/n 507490 DF. Actual measurements 29.5 outside, .50 to .54.wide .28 to.29 thick.
I purchased what was supposed to be 30 inch belt at a auto parts store an put it on. Everything looked ok untill I ran it up to high speed, then, excessive slapping. Would have completely tore the plastic gear rack to shreds, (headstock was moved so belt would clear the rack). Turns out the "30" inch belt was just under 32 inches. Should have checked in the store.
I put the old belt back on. Every thing seems ok then.
Has anyone tried the dayco 17295 or 17300? Looks like they would be pretty close.
Also, speed control cam is very close to hitting the cam yoke / follower,
No apparent adjustment except with the eccentric on the Idler shaft which I don't want to mess with. Maybe I will just make a new control shaft, .125 longer.
I put a piece of self adhesive UHMW tape (.010 thick) on the cam / yoke follower where it
Rides on the cam. We'll see how that holders up.
Finally got the time to tear into my new (to me) mark VII. After a little (ok a lot) of spray contact cleaner / lube on the fwd, stop, rev switch, the motor ran fine in both directions.
How does the switch come apart? Does the back just pry off? I did not want to break anything.
Anyway, now the belt question. The belt that was on the machine was / is an original? SS Magna belt p/n 507490 DF. Actual measurements 29.5 outside, .50 to .54.wide .28 to.29 thick.
I purchased what was supposed to be 30 inch belt at a auto parts store an put it on. Everything looked ok untill I ran it up to high speed, then, excessive slapping. Would have completely tore the plastic gear rack to shreds, (headstock was moved so belt would clear the rack). Turns out the "30" inch belt was just under 32 inches. Should have checked in the store.
I put the old belt back on. Every thing seems ok then.
Has anyone tried the dayco 17295 or 17300? Looks like they would be pretty close.
Also, speed control cam is very close to hitting the cam yoke / follower,
No apparent adjustment except with the eccentric on the Idler shaft which I don't want to mess with. Maybe I will just make a new control shaft, .125 longer.
I put a piece of self adhesive UHMW tape (.010 thick) on the cam / yoke follower where it
Rides on the cam. We'll see how that holders up.