Need more info on switching 120hp/3.0 engine

[jimg984]

friend has 1985 cris craft with a 3.0 mercruise outdrive with no engine or bellhousing when he got it....we are looking at a 120 hp engine which has the bellhousing complete to the back of the boat on the inside,,, not sure it will connect to outdrive at the inside of the transum.... need info,,, ths (sry i don't know the correct names for these piees) also would like to what they are called

 

[Bondo]

Re: Need more info on switching 120hp/3.0 engine

Ayuh,... Is the 120hp a Merc dressed motor,..?? What Vintage,..??

 

[jimg984]

Re: Need more info on switching 120hp/3.0 engine

Ayuh,... Is the 120hp a Merc dressed motor,..?? What Vintage,..??

its around 1980/84.... yes engine is complete with busted outdrive (outside of boat) question is will the complete assembly bolt up to the 3.0 outdrive

 

[Bondo]

Re: Need more info on switching 120hp/3.0 engine

its around 1980/84.... yes engine is complete with busted outdrive (outside of boat) question is will the complete assembly bolt up to the 3.0 outdrive

Ayuh,... Ya might have to swap the flywheel cover, so's the rear motor mounts line up,...

'n, ya might have to swap the manifold assembly so's the exhaust lines up with the down pipe...

But, basically, with the parts off both motors, Yes, it can be made to fit... The block castings are the Same, externally...

 

[jimg984]

Re: Need more info on switching 120hp/3.0 engine

we don't have the 3.0 engine and flywheel cover......true the 120 hp engine with flywheel cover rear mounts dont line up....we are hoping tto use the 120 engine/flywheel cover and the next piece to bolt to the 3.0 outdrive coming thru the trasom
whatta ya thinking?

 

[Bondo]

Re: Need more info on switching 120hp/3.0 engine

Ayuh,.... I'm thinkin' yer gonna have a Whole Bunch of fitment Issues.....

If you change the inner transom plate, the drive's input shaft is gonna be to long...
'n the exhaust probably ain't gonna line up...

 

[fishrdan]

Re: Need more info on switching 120hp/3.0 engine

we are hoping tto use the 120 engine/flywheel cover and the next piece to bolt to the 3.0 outdrive coming thru the trasom
whatta ya thinking?

If the rear mount bolt pattern (2 bolts) are different between the 2 engines, I'm almost 100% sure (well maybe 99%) that you can't swap the plates. The old and new style inner transom plate have different bolt patterns. If the transom plate doesn't match up, you are going to have a BUNCH of things that need to be swapped. Best to find another engine that's the same vintage as the drive/transom shield assy.

 

[jimg984]

Re: Need more info on switching 120hp/3.0 engine

ths for replies,,, looks like best/cheapest bet is to find a flywheel cover to match engine and rear engine mounts.... the 3.0 has mucher wider spread on rear engine mounts 15 inches vs about 9.5 ths again for walking me thru this so i got a better understanding

 

[fishrdan]

Re: Need more info on switching 120hp/3.0 engine

ths for replies,,, looks like best/cheapest bet is to find a flywheel cover to match engine and rear engine mounts.... the 3.0 has mucher wider spread on rear engine mounts 15 inches vs about 9.5 ths again for walking me thru this so i got a better understanding

There are going to be other hurdles (some might workout without incident), coupler, drive's input shaft length, crank have studs for flywheel AND coupler or bolts for flywheel only (coupler bolted to flywheel), 12 3/4 or 14" flywheel, starter going to work, exhaust elbow match up to down pipe, manifold have the correct anchor points for the shift cables or does the valve cover have the shift cable anchor points(?), wiring harness, etc, etc, etc....

 

[jimg984]

Re: Need more info on switching 120hp/3.0 engine

shift cables are not envoled with engine or the flywheeler cover..... ths for asking me the question tho lol