Head bolt torque, 1980 25 hp

[rstumpy]

Greetings,

Wondering if anyone might know the proper head bolt torque and sequence for a 1980 25 horse, model number J25TECSA? Plug hole stripped-out, but luckly I had a 35 horse parts motor.

And now for the real dumb question. Think I can get away with re-using the old head gasket? I live in the middle of nowhere and was trying to get out on the water to take my boys fishing tomorrow....getting a new one will take some time.

Thanks very much

 

[rstumpy]

Re: Head bolt torque, 1980 25 hp

Well, the sequence for tightening should be about the same as my older motors...that's not a problem.

I'm still in a quandary about the torque setting though. My books don't cover this engine, but from what I do have I figure it's either about 120 INCH pounds or 220-240 INCH pounds. That's enough of a difference for me to feel nervous about proceeding until I can find a definite answer.

Anybody have a manual that covers a 1980 25 or 35 horse?

Thanks again

 

[tx1961whaler]

Re: Head bolt torque, 1980 25 hp

I don't know about the torque, but you need to use a new head gasket particularly if you're switching heads.

 

[ezeke]

Re: Head bolt torque, 1980 25 hp

18-20 foot pounds or 216-240 inch pounds is correct.

Edit:

..9....10
5........6
..1...2
4........3
..8...7

 

[rstumpy]

Re: Head bolt torque, 1980 25 hp

Thanks much for confirming the torque setting sir. I found a new head gasket...had to drive 80 miles for it, but that's what ya get for living in the outback. Picking up a carb kit at NAPA and heading for home and an evening of wrenching momentarily.

Thanks again for the info. Have a good one.

 

[R.Johnson]

Re: Head bolt torque, 1980 25 hp

On these all aluminum engines', Use a In/Lb wrench on all low setting readings.

 

[rstumpy]

Re: Head bolt torque, 1980 25 hp

Yup....will do. Just went and retrieved my inch-pound torque wrench. In the middle of chasing the threads in the holes and on the bolts with a tap and die just now. Will likely put some anti-sieze compund on 'em too unless there's a good reason not too?


One additional question though. My old omc book (1970 and older) gives general torque settings for bolts of various sizes. The head bolts on this 1980 motor are 5/16" x 18, which my book tells me should only be torqued to 120 inch-pounds. The torque table lists 3/8" bolts at 220-240 inch pounds.

Soooooooooo......I'm wondering if my 5/16" head bolts are rated for higher torque than my book thinks they are....OR maybe other folk's data is showing these to be 3/8" when they're actually not.

I really don't want to screw this up....at least not like that. Gotta get my scouts on the river to do their eagle-scout survey project. I'll wait until tomorrow for clarification from folks here, if you can spare a couple of minutes. I surely do appreciate it. Prefer not to make my usual bull-headed mistakes on machinery of this type, ha ha.

Thanks again

 

[R.Johnson]

Re: Head bolt torque, 1980 25 hp

Look in the powerhead, or engine spec.section of your manual for head bolt torgue. The chart you a referring to is for the general, non critical fasteners.