Just unseized my 40hp-Now What?

[rodbolt]

Re: Just unseized my 40hp-Now What?

pistons are toast bores are toast.
is this thing worth boring and new pistons?
looks like a salt water engine to me.
the reason it siezed was the heat swelled the piston until the pistons got so big they simply stuck in the bore.

 

[1946Zephyr]

Re: Just unseized my 40hp-Now What?

I wouldn't necessarily write off the bores. I have seen badly scored pistons in bores that clean up nicely. Usually bores get hashed, if foreign objects get in there, versus overheating. You may have to scrape aluminum off of the bores, but I think they'll hone out fine. Your pistons actually don't look too bad for an overheated set. I would replace them though, because the scoring may be causing your rings on number one to stick and not give you a good compression reading. If you are getting water in your crank case, then that is a big UH OH. Like noelm stated, it's possible that your bearings are shot. Fortunately though, these 40's are really common engines and you can either rebuild it, or buy a good used running powerhead and just swap it out. That would save you a lot of time and give you the option of rebuilding your old powerhead just as a liesure project, without puting your boat out of commission for any length of time.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

There certainly was a lot of crystal buildup in the water cooler/exhaust jacket.
And the name in the engine cover suggested it live at a seaside city.

I could not see any obvious signs of water by-passing gaskets so I hope the head holds the key. Maybe the gasket between the power head and the lower cover plate but not sure. As I say, it wasn't obvious.

 

[noelm]

Re: Just unseized my 40hp-Now What?

water by passing anything is the least of your concerns, that motor needs to be stripped, new pistons minimum replaced, and maybe the bore is toast as well (as per Rodbolt) unless you do the right thing now, you will be just tossing money in the bin, it will fail very shortly (if it runs at all) the exhuast side is the side that gets cooked (of course) scrap it or fix it properly, you are living on borrowed time trying to patch it up as is.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

Is there a sierra Piston equivalent with part number

 

[rodbolt]

Re: Just unseized my 40hp-Now What?

as you have seen, I dont do tech in PM.
but no sierra doesnt offer them and I doubt BRP does either.
but you can check, its also possible that a dealer may have a set in stock someplace.
the bore service limit,top to bottom including out of round is .003".
about the thickness of a human hair.
anymore and that motor will be shortlived.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

Roger that.

The PM was to divert your attention back to this thread to comment as there is high turnover in threads burying mine out of site, so , thanks for doing that.

I'm just having a situation with four head bolts. I started drilling but my equipment is second rate so I will need to employ more accurate tactics.

Bearings are not rusted...thank God!

Q. Is the standard bore in this engine 3.187"

Stay Tuned!

 

[rodbolt]

Re: Just unseized my 40hp-Now What?

ever heard of drill bushings?
bullit point drills?
both work great.
other than that, sharp drill bits and a steady hand.do it myself several times a week.


bad thing, my vision is fading and I cant find a kid that wants to learn.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

In answer to your Q's:
a) No
b) No

I know what a drill bit is. I will get something sorted.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

Yesterday I discovered the oil ring on the low compression cylinder was stuck in directly opposite to the ring ends. With the residual lose juice and a gentle wobble the ring come free. The bore has no obvious scoring and I think it will hone up well, after micrometer test

The #1 piston has a patch of scoring and rust below the piston pin and the #2 has a small thumb size score mark below the piston pin. I don't know if these will rub out and be nothing to worry about but I will ask the engine shop?

I couldn't see any obvious sign where water was getting past the head gasket so it may have been coming from the exhaust gasket?

I still have head/exhaust and power head to leg bolts to drill out but I have managed to drill 1/8" hole through all bolts. I may have to use a helicoil on a few.

 

[1946Zephyr]

Re: Just unseized my 40hp-Now What?

See? I told ya the bores may be okay

 

[PaulO]

Re: Just unseized my 40hp-Now What?

The only problem is... some water pissing out the bottom of the exhaust cover. I will have to take the power head off again and possibly look at placing silicon around the water cover.

 

[1946Zephyr]

Re: Just unseized my 40hp-Now What?

I wouldn't use sillycone on that. I would use permatex on it, instead. Sounds like you got 'er runnin huh? Good deal.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

Yes you are right. I have a high temperature RTV gasket silicone. That should not have any acids in it. Do you think that would be acceptable?

I will also need to find an equivalent of permatex in Australia.

It started with the second pull. All in all, I am pretty happy... apart from the water issue:facepalm:
I managed to work out the idle setup in it. Now I just need to take it for a run at higher power to find the High RPM needle position.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

I test run my motor today for the first time on a 14' fibreglass hull.

1.) The engine was missing and eventually got worse.

Fix - Previous owner had two wires running off the kill switch. Wires were making contact with the engine body. Wires separated!​

Result - Beautiful!​

Engine achieved Average 36 Km p/hr (21 MPH) The prop is 10x12. It does the job. Now lets see for how long???

 

[tjf]

Re: Just unseized my 40hp-Now What?

Yes your right ask anything, some people like to add there rude comments because there bored.. Coke of cola also can loosen bolts to.

 

[jonesg]

Re: Just unseized my 40hp-Now What?

Good job, you can buy the service manual now its fixed.

 

[Mas]

Re: Just unseized my 40hp-Now What?

Did you end up replacing the pistons or not???

Mas

 

[wilde1j]

Re: Just unseized my 40hp-Now What?

If you're planning to replace with std bore pistons/rings, you're wasting your time and money.

 

[PaulO]

Re: Just unseized my 40hp-Now What?

tjf
Not sure of the intent of your post.

jonesg
I got one on CD in .PDF format. It's a bit convoluted.

Mas
No. I just rubbed the rough spots with emery paper. Cylinders were in tolerence. New rings. Pistons in same hole. Bores honed through engine shop

wilde1j
Based on the above would you care to give me a life span in hours based on operating conditions? I'm curious to see how long it lasts.

P