Potential buy "Single inline 6 cyl mercruiser motor" unknown year

[scrampbell]

Hello I/O geniuses! I'm going to look at a boat later today that has a "Single inline 6 cyl mercruiser motor" with a "newer outdrive" and I'm looking for some tips/advice.

The guy says it will crank but needs some carb work. I know that more information would be very helpful here, but I thought that engines like this were usually fuel injected. Is that true?

Apart from that, what else should I be looking for when I go to evaluate this buy? I have a compression tester. Do I need to test compression if it runs on the muffs?

Thanks!!!

 

[Bondo]

Re: Potential buy "Single inline 6 cyl mercruiser motor" unknown year

I know that more information would be very helpful here, but I thought that engines like this were usually fuel injected. Is that true?

Ayuh,...Considerin' that motor ain't been used by Merc since the late 70s,...
I'm guessin' this is a pretty old scow...
That case, Everything is Suspect, to be Rotten, 'or just Worn Out....

Fuel Injection is a fairly New conscept in boatin'...
Comparatively speakin' anyways...

 

[scrampbell]

Re: Potential buy "Single inline 6 cyl mercruiser motor" unknown year

Thanks for the reply Bond-o. (And for setting me straight.) Could you verify/answer a couple of other things for me? I've got some experience with my 1984 Johnson 70, so far solving "carb issues" and a no spark situation, but if you feel this boat should be avoided because of the motor's age and my lack of experience then please let me know that. I'm really looking for an experienced opinion here. (granted, on very limited information from me)

If it really does just have some carb issues that I can fix then I'll be looking to buy it, fix it, and resell it.

Update: the guy says he can get it cranked, but that it won't stay running. He says he's selling because the landlord at his beach rental house is demanding he get it off the property.

1. So I guess I should go ahead and check compression... I'm looking for relative consistency across all 6 cylinders, right? 100+ psi or is lower acceptable? I'm going to check the spark on a tester at the same time I check compression.
2. I should expect this to be a 2-stroke motor, right?
3. Please tell me the top one or two things you'd be looking for if you were me and going to look at this boat. For instance, if it cranks but won't say running then is there anything specific I should be looking for during/after crank? Is it worth checking the fuel pump? How many carbs am I looking at on this motor?

Help me out here! Thanks again!!!

 

[Bondo]

Re: Potential buy "Single inline 6 cyl mercruiser motor" unknown year

1. So I guess I should go ahead and check compression... I'm looking for relative consistency across all 6 cylinders, right? 100+ psi or is lower acceptable? I'm going to check the spark on a tester at the same time I check compression.
2. I should expect this to be a 2-stroke motor, right?
3. Please tell me the top one or two things you'd be looking for if you were me and going to look at this boat. For instance, if it cranks but won't say running then is there anything specific I should be looking for during/after crank? Is it worth checking the fuel pump? How many carbs am I looking at on this motor?

Ayuh,... #1,... 150psi is about right....
100psi is a rebuildable core, not a runnin' motor...

#2,... Nope,... It's an automotive motor,... 4 stroke...
Except for an abomination built by OMC in the 60s,...
I/Os are All 4 cycle motors...

#3,... I'd be lookin' to see how Rotten the wood in the hull is...

 

[crewscontrol]

Re: Potential buy "Single inline 6 cyl mercruiser motor" unknown year

The only in-line 6 cylinder engine that Mercruiser used was the old 250 CID Chevrolet. Mercruiser rated it at 165 HP. I had a 1972 Aristocraft 19 foot boat that had one. I never had any problems with it. As others have said, it has been at least 35 years since the last one came of the assembly line. Nobody knows how this one may have been treated. As others have posted, every engine part is still available if it needs something. However the much bigger question is, how good is the boat the engine is sitting in?

 

[HT32BSX115]

Re: Potential buy "Single inline 6 cyl mercruiser motor" unknown year

The only in-line 6 cylinder engine that Mercruiser used was the old 250 CID Chevrolet.

Well, I wouldn't say that the "250" is the "ONLY" one they used......there was the 230, 250 and 292 all (somewhat) similar I guess.....

 

[cannonford57]

Re: Potential buy "Single inline 6 cyl mercruiser motor" unknown year

well,i've learned sumtin today.i thought mercruiser only used the ol bulletproof 250 too.