A few magum 18 questions

Numbnuts · #1 09-09-2014, 10:32 PM

Hello Folks

I have an M18 w/700+ hours from an 1811 to re-power my 782 that seems in nice condition, but has some minor issues.

The crankshaft oil seal on the clutch side (front?) leaks a little and I would like to replace it. A shop quoted me ~ $400 to replace both front and rear. Can just this seal be replaced w/o splitting the motor? Kind of bothers me that the seal is stamped 'Singapore' !! (gulp).

Second issue is that fuel is dumping into the crankcase. I replaced the fuel pump, cleaned the carb, and checked the float level which seemed OK -- still dumping fuel. The same shop wants ~ $300 to rebuild the Walbro carb to fix the float issue -- which sounds crazy. Is the float assembly that big of a deal to replace and setup right yourself? Seems like this is a common problem with them, are these carburetors junk?

thanks

J-Mech · #2 09-09-2014, 10:48 PM

Yes the seals can be replaced without splitting the motor.

No, a carb kit isn't that hard to put it. Rebuilding a carb, that is different. $300 for a real rebuild, install and tune, well..... that's a little high, but not really all that far off. $400 to put seals in... that's high. Even at the rate I charge.

Go to the tech section and download the manual on the M18. There are only like 100 carb rebuild threads and seal replacement threads on here. Just do a search.

Numbnuts · #3 10-05-2014, 10:16 AM

Thanks for the reply and great info, carb rebuild ended up only costing $190 -- seals were actually fine.

One more question ... I couldn't seem to find information on installing the PTO clutch. Is there a torque spec for the end bolt that goes into the engine shaft?

Thanks again, appreciate it.

dvogtvpe · #4 10-05-2014, 10:23 AM

common sense tight or use the std nut and bolt torque spec from the std nut and bolt torque spec chart http://www.imperialsupplies.com/pdf/...rqueCharts.pdf

Sam Mac · #5 10-05-2014, 02:09 PM

Quote:

Originally Posted by dvogtvpe

common sense tight or use the std nut and bolt torque spec from the std nut and bolt torque spec chart http://www.imperialsupplies.com/pdf/...rqueCharts.pdf

Don

Do you think a 1" impact would be too much? I just had to go there.

Numbnuts · #6 10-05-2014, 02:22 PM

Common sense tight ok with me, just saw the bearing race behind the washer - thanks.

Numbnuts · #7 10-05-2014, 02:34 PM

After it's mounted and the air gap adjusted, should the belt pulley spin free or should there be some resistance? If some resistance is ok, wouldn't that cause overheating when the PTO switch is off?

Sam Mac · #8 10-05-2014, 03:38 PM

Once you adjust the air gap it should stop the pulley or at least make it hard to turn. The bearing in the pulley allows the shaft to turn freely when the PTO is turned off.