Special tools for rebuild and specs

[scatgo]

I have a 1980 35 HP Johnson that will need a rebuild but I cant seem to find the specs i will need in my manual. The manual mentions piston and ring clearance but nothing on bearings or end play for crank. I have all my machine shop tools for checking out any specs but any other special tools needed?

 

[racerone]

There are many details in a FACTORY manual.----But you will not find a number for " end play " on the crank.----Just not needed on your motor on account of the way the crank is supported.----Just install a new bottom bearing.

 

[boobie]

What manual do you have ??

 

[scatgo]

Selco online manual. One thing i would like to find is bearing clearance for both ends of the connecting rod. And the center bearing that supports the crank. If anyone can get that info my way I would appreciate it.

 

[racerone]

I have to ask.-----Why do you feel you need that information ?.----What would you do if the connecting rod crank end bearing clearance was out of specification. ??

 

[scatgo]

Well for starters it will the me know how good or bad my situation is and if posable fix it. A new connecting rod might be needed to bring things back to spec.

 

[racerone]

You would have to buy a new crankshaft , new rollers and new connecting rods.-----Not worth doing.---

 

[scatgo]

I guess your not going to give up those specs hu?

 

[F_R]

Take it easy, scat. Fact is, the factory manuals simply do not give those specs. If anything, the most they will say is something like "Roller Bearing". Anyway, precious few techs have a way to take such precise measurements, which will run at least four or five decimal places. Instead, we just go by the maxim that they should look like brand new with no pitting, burning, etc. Those things just don't wear unless subjected to abuse like water ingestion, etc. In that case, no measurement is required, they are NG.

I don't have the book for a 35hp, but here is what is given for another model (15hp) factory manual..

 

[achris]

Well for starters it will the me know how good or bad my situation is and if posable fix it. A new connecting rod might be needed to bring things back to spec.

2 stroke conrod bearings (both big and small end) are different to 4 stroke engines. For a start they are needle rollers, not a plain metal shell bearing. They are oiled 'passively', unlike 4 strokes which oil under pressure.

There's no spec for the clearance, because there is no clearance. You check it with you fingers. If you feel movement, it's too loose. Toss the crank and rods, buy new. You can't grind the journal and fit larger needles, it doesn't work like that. For a start, the crank journals are hardened, and if you managed to grind it, you can't re-harden it. If the engine was 'rattly' before you pulled it apart, probably not even worth pulling apart.

And please, stop giving the people trying to explain and help you a hard time. We do this for free, and no abuse of fellow members will not be tolerated by the mods!

Chris.
iboats mod team.

 

[scatgo]

Thanks F-R and achris.That is the in depth type of info i need.

 

[racerone]

???--What ?----There absolutely has to be clearance on those roller bearings !!----The numbers are just not posted in manuals.-----If you are working on your first motor this can be baffling I guess.----If you feel movement it just might be CORRECT !!----This is just more proof that lubrication in a 2 stroke and the way bearings actually " work " is not well understood.

 

[scatgo]

Listen. I have rebuild many dirt bike engines. Two cycle of course. Most of the time the spec might be side play at the top of the connecting rod. Or up and down play at the top of the rod. Hook up a indicator and go. This was the infomation giving and it worked. Any info is better that none.

 

[racerone]

Good luck with your project.

 

[scatgo]

Any one have the specs. Going nuts trying to find them. Cant get a factory manual.

 

[flyingscott]

Any one have the specs. Going nuts trying to find them. Cant get a factory manual.

When you look at the parts diagram, do you see any shims? Or any way at all to adjust endplay? Maybe you should drop the attitude and listen to what people are telling you.

 

[F_R]

Ken Cook Co has the license to reproduce the factory manuals. www.kencook.com

 

[scatgo]

When you look at the parts diagram, do you see any shims? Or any way at all to adjust endplay? Maybe you should drop the attitude and listen to what people are telling you.

I am. Getting a little attitude myself.

 

[scatgo]

Ken Cook Co has the license to reproduce the factory manuals. www.kencook.com

Thank You! Great Info!!

 

[achris]

When you look at the parts diagram, do you see any shims? Or any way at all to adjust endplay? Maybe you should drop the attitude and listen to what people are telling you.

Maybe I read it wrong, but I think the OP is looking for bearing clearance, not end float. As I said in my post, the spec for clearance, on roller bearings is zero. End float is a different story.

Chris.........