How many hours before rebuilding a 225 Promax

[Wicky]

Compression is 121 in five holes and 120 in one hole. Test was taken at 3000 ft.
No leakdown test.
Motor is 13 yrs old with a ton of hours on it.
Runs perfect. Hits limiter very easy with a 30"prop @ 3000ft.
Still kicks big block *** all day long.

 

[K-DAWG XB 2003]

I would get a leak down done. It will tell you the health of your rings and bore.

 

[K.Kiser]

If the leak down is less than 10%, I'd keep standing on it... If they're maintained well it's not uncommon for them to go easily over 1,000 hours... Again, the leak down will tell the tale...

 

[msharp]

Not sure what a ton of hours is , but I've built several with 500 to 600 hour's, good cyl's , BUT the ristpin clips working there way out of the piston . Something to think about !

 

[Fl Boy in ILL]

Todd
That has to be the best 225 Merc ever built, me first and then you and its a 1997 and it has NEVER been apart. WOW thats all I can say. I hope you don't have to build it for another 5 years, LOL.

Rick

 

[Hotprop]

Leakdown or compression is not usually the culprit on that engine . The ring locator pins is the usual culprit on that engine or the plastic caged rod bearing will fail . I have seen failures as early as 250 hours and I have seen them last much longer than that . 13 years is a long time I would say you are on borrowed time and your due for new pistons and bearings .

 

[jaybluez]

You ever heard the phrase 'let a sleeping dog lie'?

Fix it when it breaks.

 

[K-DAWG XB 2003]

Leakdown or compression is not usually the culprit on that engine . The ring locator pins is the usual culprit on that engine or the plastic caged rod bearing will fail . I have seen failures as early as 250 hours and I have seen them last much longer than that . 13 years is a long time I would say you are on borrowed time and your due for new pistons and bearings .

I would take Jeff's advice. If anyone on this site is qualified to answer the question he has just spoken. Never thought about the pins.

 

[GotMyAlly]

You ever heard the phrase 'let a sleeping dog lie'?

Fix it when it breaks.

That'll cost you more in the long run....

 

[jaybluez]

And it might not cost anything at all.

Having it freshened up will not prevent a failure. If it's going to happen it will happen. Why spend money on a perfectly operating outboard? Just sayin.

 

[msharp]

They are ALL a GRENADE with the PIN pulled !!!! :furious Its not IF, its WHEN !!! Would be cheeper to put piston's and bearing's in now then when the pin's or clip's come out !!!!:help
IMHO !!!!:big grin

 

[1badss]

The way you baby that thing it'll never need a rebuild................Just sayin......

 

[Wicky]

I did finally get it past 74mph last summer 1badss. Hoping for high 70s this summer!!

 

[bigtis]

new metal caged rodbearings, and some vertex pistons would be a easy and cheap insurance policy.

I've alway's liked the 96 and 97 225 promaxes. Believe it or not, ALL of the original never apart 225's I've had were 96's or 97.

I bought a 260 that SHOWED it to be a perfectly heatlthy engine. comp was within 2-3lbs. and the leakdown was between 5-8% BUUUUUUUUT, After the first attempt of putting it in the water, It was 5 minutes after had it in the water for the first time, that it spit a side pin for the ring, and ate up #4.

Talk about upset. First time I get into the boat I run it 100mph then the damn thing locks up.

Ya just never know. When ya build em up, ya normally get to see what's going on inside the engine. that helps if there's a small problem waiting to cause a big problem.

 

[1badss]

new metal caged rodbearings, and some vertex pistons would be a easy and cheap insurance policy.

I've alway's liked the 96 and 97 225 promaxes. Believe it or not, ALL of the original never apart 225's I've had were 96's or 97.

I bought a 260 that SHOWED it to be a perfectly heatlthy engine. comp was within 2-3lbs. and the leakdown was between 5-8% BUUUUUUUUT, After the first attempt of putting it in the water, It was 5 minutes after had it in the water for the first time, that it spit a side pin for the ring, and ate up #4.

Talk about upset. First time I get into the boat I run it 100mph then the damn thing locks up.

Ya just never know. When ya build em up, ya normally get to see what's going on inside the engine. that helps if there's a small problem waiting to cause a big problem.

Damn Tis, I gotta agree wit ya. I pulled my powerhead because the flywheel WOULD not come off, period. Cut it off finally and ruined the crank. When I tore it the rest of the way down to put a crank in I had one piston ready to go, three cracked rods and one galled rod. All the nitride rings were shot too. All this just because the stator went bad! I saved the block but just barely.

 

[Jr in Jax]

I put over a thousand hours on my first '98 Pmax powerhead and compression was still good. I had a leakdown done and one cylinder was slightly low so we pulled the head. The cylinder had a very slight scuff but my Tech said it would easily go another season. I purchased a Merc NEW powerhead and put it on and it has over 500 hours now. I keep my limiter set at 7K.

 

[Ally-Sun]

I was just researching old ProMax rebuilds while in the midsts of mine. I stumbled across this one by Todd and found it interesting. To update I purchased Todd's GS back in July. Which was in great shape. Todd was very honest about the engine, the hours, and how he ran the snot out of it most of the time. He also ran high octane gas and 32:1 premix oil with the oiler removed. So I had budgeted for a rebuild when I bought the boat. Nine years after this post and what Todd estimates over 1,000 total hrs. The ole gal was still running great. Yet I went forward with the rebuild, which was a good decision. The #4 piston ring locator pin had worked loose and barely scuffed the cylinder wall. The number one rod bearing had a cracked plastic cage. Nothing had moved...yet!...but it was cracked. The exhaust chest had a crack on the bottom at the base. Last but not least the reeds were pretty much shot. All of these are common wear and potential failure points. Oh, by the way compression at 27 ft. above sea level was still 120-123 lbs. (Compared to Todd's 120 @ 3000 ft.) I am in no way bashing Todd he is a honest dude and we still chat all the time. He was a great guy to deal with and I couldn't be anymore happy with the purchase I made. It was a 5,000 mile round trip, well worth taking. I just wanted to provide info for people researching for a rebuild as I did. This engine was 22 years old and had over 1,000 hrs on her. Yet at that point she was a ticking time bomb. I think the ole 225 ProMax had paid her dues for sure!

 

[Rick Propst]

im getting ready to start building a brand new 225 promax (straight from Mercury Racing) myself, getting all my parts together as we speak just went and picked up my WSM pistons on Friday now need to get bearings and Rod bolts as well as gaskets,, Good luck on the rebuild ALLy-Sun

 

[Ally-Sun]

im getting ready to start building a brand new 225 promax (straight from Mercury Racing) myself, getting all my parts together as we speak just went and picked up my WSM pistons on Friday now need to get bearings and Rod bolts as well as gaskets,, Good luck on the rebuild ALLy-Sun

Thanks Rick, good luck to you as well! Shoot me a PM we can compare as we go. I should get my block back in the next few weeks. Then it’s go time!
Take care,
David