Just unseized my 40hp-Now What?

[PaulO]

Hi.

Just picked up a 40hp 40RL71G that was seized. It would have been run with a ruined impeller so got hot. The plugs were oily - no appearance of rust.

I filled both cylinders with fuel/ boat oil mix and let sit for a few days. #2 let go of its contents. #1 absorbed a little bit but held most of its contents. This morning I tipped a kettle of hot water down the pee hole to see if it would expand the cylinder and help with the absorption. I was able to unseize it simply by gripping the inertia wheel and rocking it with my hands. I was surprised how easy it gave up with only a few rocks.

I have done a compression check cold and the #1 = 72 PSI #2 = 109 PSI.
I notice in the sticky it says to run the engine to warm up before doing a compression test. Given my circumstances are slightly different should I attempt to run the engine and then do a compression test? or should I pull the intake covers and or head and look at the rings and walls? I don't want to disturb the head gasket if I can help it.

Thanks,

Paul

 

[1946Zephyr]

Re: Just unseized my 40hp-Now What?

Well, I would run it and go extra heavy on the oil mix. Run it about 16:1 for a couple hours then take another compression test. Chances are, things could improve and work loose.

If your number one cylinder is that low, then I would say your piston is badly scored and the rings are stuck in the grooves. The number two cylinder seems okay. Chances are, if it is scored, it's not too bad.

 

[SeaKaye12]

Re: Just unseized my 40hp-Now What?

Unless you are prepared to fix what you find wrong, I see little point in taking anything apart.

Zephyr's advice is good....but run it with the understanding that it's possible that things will get ugly; depending on what damage has been done. But; I don't see that you have much to loose....

I've known many people who get motors un-stuck...and most of those motors run for years with no obvious issues. What a credit to the engineering; eh?

Good luck, Chuck

 

[Rick.]

Re: Just unseized my 40hp-Now What?

You don't want to disturb the head gasket? Overheating may have already done that for you. I would change it and then retest your compression as a first step. While your at it you can have a look at the cylinder walls. Best of luck. Rick.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

Thanks chaps.

I'm surprised how easy it came unstuck which makes me wonder if the scoring is really that bad???

I might take the intake manifold cover off and have a look at the rings. I might even poor a lot of kerosene in there if they look stuck.

I will take all advice on board and report back. At a later date.

Once again. Thanks for the quick response.

Paul

 

[PaulO]

Re: Just unseized my 40hp-Now What?

Feller's,

It just occurred to me, when I was poring hot water in the pee hole some water ran out of carby. There didn't appear to be water on the piston but then again I didn't see much piston through the plug hole. The engine was horizontal with the carby throat pointing down.

This engine was left to a grandson so it wasn't run for a long time. The grandson said he gave it a run so I take it to mean it was run in a drum or on the muffs(you know what I mean) I am guessing this was a low rpm seizure if there is a such a thing. Whether that makes any difference i do not know.

Is the inner exhaust cover stainless or aluminium in this engine? I'm thinking about what Rick said about the head gasket.

Paul

 

[tx1961whaler]

Re: Just unseized my 40hp-Now What?

Feller's,

It just occurred to me, when I was poring hot water in the pee hole some water ran out of carby. There didn't appear to be water on the piston but then again I didn't see much piston through the plug hole. The engine was horizontal with the carby throat pointing down.

This engine was left to a grandson so it wasn't run for a long time. The grandson said he gave it a run so I take it to mean it was run in a drum or on the muffs(you know what I mean) I am guessing this was a low rpm seizure if there is a such a thing. Whether that makes any difference i do not know.

Is the inner exhaust cover stainless or aluminium in this engine? I'm thinking about what Rick said about the head gasket.

Paul

If water came out of the carb, then water is in the crankcase and is rusting things up as we type. The inner exhaust plate can be either stainless or aluminum, but is probably stainless in 1971. It's still available from a dealer.

 

[1946Zephyr]

Re: Just unseized my 40hp-Now What?

Water came out of the carb? Oh Schitt....you have some major issues then.

 

[samo_ott]

Re: Just unseized my 40hp-Now What?

Yes, get oil in there pronto. could be too late. and I agree with above, change the head gasket if it overheated.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

What I did was put a heep of kerosene down the carby. I thought this may penetrate through to the rings via the gudgeon pin loosening them up (if they were stuck in). I hope this won't hurt it.-- Please advise

I am going to pull the power head off it and take the head off, the reed valve cover, exhaust cover and intake port covers. May as well have a proper look.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

I have taken the bolts that hold lower cover plate and engine block to leg. Three rear bolts had to be drilled. There are two 1/2 or bigger bolts each side of leg removed plu everyone towards the back.

• Are there some hidden at the front? I can't get the transom swivel off

and there is still a rubber mount bolted behind the steering bar.

• How do I get to that. What else am I missing?

UPDATE:

I have seen two 1/2 inch nuts close to and each side of the front centre line of the engine. They are very difficult to get to and I don't see any where external I can gain access. Any ideas?

Need advice on getting the transom swivel off the upper shock absorber.

Thanks.

Paul

 

[Fisherball]

Re: Just unseized my 40hp-Now What?

Buy a manual for your motor!! It'll tell you all you need to know. Like how to take it apart. Best $30.00 you'll ever spend on the motor.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

Buy a manual for your motor!! It'll tell you all you need to know. Like how to take it apart. Best $30.00 you'll ever spend on the motor.

1) I thought that was the purpose of this boating forum?
2) They are about $75 in Australia and I can't afford to spend too much without knowing whether I have a boat anchor or serviceable engine.

Update

I got transom bracket off the leg. I don't know how I will get the upper rubber shock absorber back in?

I got the two forward nuts off, from under the carburettor, that hold the block to the leg.

Problem: 4 of the Cylinder head bolts will not budge. What are my options?

 

[1946Zephyr]

Re: Just unseized my 40hp-Now What?

Any bolts you have that appear to be stuck, I would heat them up with a blow torch. This could take several times of heating the stuck bolts up, before they break free.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

1964Zephyr

I will check it out ASAP. I will take off the other covers tomorrow and report back.

Thanks.

P

 

[1946Zephyr]

Re: Just unseized my 40hp-Now What?

yea, you can get a nice visual of your pistons, through the bypass covers. If there is any scoring, you'll definately see it through the ports.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

I'm happy so far with what I have seen. No apparent scoring. I will have to drill a bolt out of the exhaust cover.

Top #1 Piston: low compression 72 PSI Pulling over with a rope start

Bottom # 2 Piston: high compression 109 PSI Pulling over with rope start

Maybe that rust in the good cylinder came from the water up the pee hole?

I will get the exhaust pics up when I get the cover off.

 

[noelm]

Re: Just unseized my 40hp-Now What?

Kind of think I would be removing the head to inspect, there is rust in both cylinders, chances are the bearings are also rusted, and these will last no time at operating speed, the cylinder/piston rust MIGHT clean itself out, but it just might not too. How easy it came un seized is completely irrellevant to the health of the engine.

 

[Tim Frank]

Re: Just unseized my 40hp-Now What?

Sure looks like an overheat from the paint gone around head/head gasket joint.

Another vote that you have to get the head off for a look-see.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

Ok. There is scuffing on the top side of both pistons and the bottom of piston 1. When I say that I mean if the pistons are horizontal the top and bottom refer to the sides.... know what I mean. I'm confused

Cyl/Piston #1:

Cyl/Piston #2:

The head is going to be the pain