MERC 7.5 H.P. TO 9.8 H.P. CONVERSION

[PICSTEVE]

I WAS AT A MERCURY REPAIR SHOP THIS MORNING, AND HE TOLD ME THAT MY 1980 7.5 MERC. COULD BE CONVERTED TO A 9.8 H.P. WITH A CARBURATOR SWAP. IS THIS TRUE, OR IS THERE MORE TO THE STORY.

 

[Laddies]

Re: MERC 7.5 H.P. TO 9.8 H.P. CONVERSION

If that were the truth mercury would not have sold may 9.8 engines

 

[Chinewalker]

Re: MERC 7.5 H.P. TO 9.8 H.P. CONVERSION

Much more to the story. The intake and exhaust porting on the 9.8 is larger. Installing a larger carb will only make it run like crap. Lots of those motors around with busted up lower ends - find a good 9.8hp powerhead and go with that... Or, at the very least, a good 9.8hp block, as your pistons, rods and crankshaft would install fine. Only then would you be able to install the 9.8hp carb...<br />- Scott

 

[dajohnson53]

Re: MERC 7.5 H.P. TO 9.8 H.P. CONVERSION

I believe you could put a 9.8 cowling on it though and fake it!

 

[WillyBWright]

Re: MERC 7.5 H.P. TO 9.8 H.P. CONVERSION

You'd never know the difference.

 

[bammgelo]

Re: MERC 7.5 H.P. TO 9.8 H.P. CONVERSION

I have a 7.5...<br />I enlarged ports, 9.8 carb but nothing appen<br /><br />the mistery are reed valves: in 7.8 opens 4 mm.<br /><br />I have machined crankshaft: now valves open 6.5 mm. Now I have 10 plus Hp.