35 hp 40hp swap

[bandit]

i have a 35 hp pull start runs good and a 40hp elec start blown power head can i put the 40hp flywheel on the 35 hp would like to make the 35 elec start but need the fly wheel of the 40 both motors are 1970 to 1975 mercs

 

[Chinewalker]

Re: 35 hp 40hp swap

Hi Bandit,<br /> Not sure if your years are correct - they didn't make a 35 in 1970. Anyway, the 35s up to 1969 and the 40s of the 1970s used different ignition systems, so the flywheels won't interchange. You MAY be able to do a complete ignition swap, but might be more trouble than it's worth. I think the various mounting bosses are different, so it might take a great deal of jury-rigging. If you can find the correct 35hp flywheel, I am pretty sure the starter itself will swap out...<br />- Scott

 

[WillyBWright]

Re: 35 hp 40hp swap

Can you just swap the ring gear for the ring without the teeth? I think they're just screwed on.

 

[Chinewalker]

Re: 35 hp 40hp swap

The ring gears on the Mercs are welded to the outer ring of the flywheel. The outer ring has the magnets for the ignition system. The magnets changed in number and position depending on the ignition being used.. So, the short answer is that no, you can't swap one for the other unless the magnets are EXACTLY the same. Also, keep in mind that by undoing the outer ring from the hub portion you must keep the relation of the ring to the crankshaft key intact. Using a punch, tap an alignment mark into all three flywheel parts, or use some paint to mark them so that you can reassemble them in the same relation as originally assembled.<br /><br />- Scott