200hp black max questions

[rjcamel2355]

Hey guys,
I picked up a 2.4l chrome bore black max last week. Ran a compression on it. 120-125ish on each cylinder EXCEPT #2 being around 80 psi. Squirt a teaspoon of oil it jumped up to 125.

Engine has been setting for 4 or 5 years. It idled fine also ran excellent (prior to and after running the compression)

I'm assuming its a stuck ring, but I figured i would toss it out there and see what everyone else thinks.

Any solutions to bring the compression up?

I've been told I can pull the intake undo the rod bolts pull the head slide the piston out. Quick hone rings and right back in with it.... I've done a few v4 omcs but I had to split the case on those.

I'm not against re ringing one cylinder. But if there's a chance to get the ring to free up I would like to try that.
My grandpa was a gm mechanic and told me stories of using liquid wrench to free it up.

I've personally used atf on cars before and it worked. But I dont want to do that to an outboard unless someone with more knowledge recommends it.

Engine idles great jumps up on a pad and wants to turn a 23p prop way too many rpms it hit 7000 on the tach before I noticed it and I pulled her back down quick (I keep it held back under 5500 usually 4500 just cruising around)

I rebuilt the fuel pump cleaned the carbs new impeller and poppet valve.

Its on a skeeter 150 starfire 17' boat.

I'm not against pulling the head or anything like that but again if its just a stuck ring it seems like a waste of a gasket.

 

[Faztbullet]

You cannot hone a chrome bore and if compression is low it usually a scuffed cylinder. Depending on damage if aluminum build up it may possible be salvaged with acid cleaning. If chrome is damaged it will need resleeved....

 

[Dukedog]

doubt its gonna be a "stuck" ring... 99.9% of tha time thats a myth with tha merc V6!... more like what fast describes... tha "do it without splittin' tha case" thing is for tha very experienced and/or a "hafta situation" ie: at tha races..............jmo

 

[rjcamel2355]

So, best bet would be to pull the head, inspect the cylinder and if the chrome is damaged..... I'm looking at splitting the case, having the cylinder sleeved, new piston/rings?

Was hoping for it to just be a ring job, but the way you guys are describing it it's gonna be a tear down...

 

[Dukedog]

even doin' tha way fast suggest (acid cleanin') it needs ta be tore down... no matter how hard ya try no way ya can keep any bits n pieces (plus acid) from scatterin' elsewhere through tha motor... jus one little drop of acid anywhere on tha crank and/or bearings and they're toast...jmo.

 

[rjcamel2355]

I've been looking around for the head gaskets, seem to be quite a few floating around. Any way you could point me in the right direction (part number/link) so I know what to grab... I'll pull the head, post some pictures and let the experts (you guys) tell me where to go with it... Just see how bad it is... Kinda want to have the stuff on hand when I tear it apart (If it's going to be ridiculously expensive, I'll just run it to the ground and find a 2.5 block)

 

[Dukedog]

try these

http://parts.promarineusa.com/productdetail/M50/1/1/246-1

 

[rjcamel2355]

try these

http://parts.promarineusa.com/productdetail/M50/1/1/246-1

Thank you, I'll get it on the way, then post some pictures of what I find, May be early next week.... Maybe I'll luck out (Somehow?)

 

[flyingscott]

They can be re-chromed which is cheaper than a sleeve U.S. Chrome in Fond Du Lac WI. can do it. It is a myth that chrome can't be honed I don't know where that comes from

 

[rjcamel2355]

They can be re-chromed which is cheaper than a sleeve U.S. Chrome in Fond Du Lac WI. can do it. It is a myth that chrome can't be honed I don't know where that comes from

I'm new to the whole chrome bore thing (first one I have ran across).. I've read across forums about honing them LIGHTLY, but I don't want to take a bad situation and make it any worse... If that makes any sense...

I'm not exactly sure what I am up against yet even.. I know (looking through the plug hole) the top of the piston is black (Carbon, I assume)

Just for another opinion, what would you recommend/what would your approach be Flyingscott?

 

[flyingscott]

I would call U.S. Chrome they have done my motors and they are knowledgeable. They also do a ton of mercury blocks and have done my blind bore 25 hp blocks and I have had excellent results. Yes I only hone them lightly because mercury chrome plating is pretty thin. Once you take it apart you can decide where to go from there.

 

[Faztbullet]

It is a myth that chrome can't be honed I don't know where that comes from

Try factory service manual page 4-19


I thought US chrome quit chrome plating a couple years ago and now do Niskal instead of chrome.....and this is honeable with a diamond hone.

 

[Dukedog]

easy enough... call us chrome and ask.. think its gonna cost way more than what ya wanna invest.. don't think they can/will do (re-plate) "one" hole ina six hole block... if that hole has been hot, which is probably tha cause, it will need "other work" ta straighten it out before any coating is applied even if they can do "one" hole.... steel sleeve will be only cost efficient way ta fix it......

Fast... they don;t do Nikasil anymore thanks ta epa... they go with Nicom now.

 

[Faztbullet]

If I have a cylinder damaged I just sleeve it.....and ifs it a old 25hp I get the Promarine block kit.

 

[rjcamel2355]

Plan on pulling the head Sunday evening, I have been calling around getting estimates on sleeving the bad cylinder (if need be).

One place has quoted me $350 per hole (Seemed high to me)
Another has quoted me $100 per hole plus the cost of the sleeve. (Seems pretty cheap to me)

I'm not an expert on this, but what is a "reasonable" cost for something like this? The place that quoted me $100 said they can do it, but they do not have the tool to "blind bore"? I believe was what he called it, but I could be wrong.... I have a friend who has took several blocks some outboard, and some automotive to this place to have done, and he recommended I go there.

Could someone point me at a Piston/ring kit to go back with? I know I'll need to use chrome rings, but will "any" piston work, or will it have to be something aside from stock to work in the steel sleeve?

 

[rjcamel2355]

US Chrome just gave me a call, if anyone needs the information for future reference it is as follows:

1038 to replate EVERY Cylinder, they will not do single cylinders.
1105 to replate and do any boring (if any needs done)
1200 + 20 a hole to replate/bore and do any welding if needed.

Definitely going to look at the sleeving route.....

 

[rjcamel2355]

I've been digging around, and I found these rings: http://shop.tsmperformance.net/Pist...-150-225hp-Steel-Bore-1978-1989-TS-200-10.htm

Seems to be the ones I am needing judgin by the "Cylinders that have been Resleeved must use this ring set"

Correct me if I am wrong though.

 

[Faztbullet]

Yes you need a special ring to run in a steel sleeve motor and you can use stock piston. The $350 route is pretty close as you have to cut plating out,bore liner,heat and drop in sleeve,flycut block and bore out to 3.377. It might be cheaper to find a 2.5. You can get the same parts here on iBoats that that TSM supposedly manufactures and by the real manufacture.
http://www.iboats.com/Merc-Cast-Iron...iew_id.1178976