Cylinder Bore Repair

**InjectorService** · 12-08-2020, 01:00 PM

So I found a good 2016 short block, it had sunk but was supposed to be in good condition. The guy who has it coated the cylinders with ATF. It appears that something has now pitted out those liners. I haven't bought this block yet, but theres not tons of them out there to pick from either.

What would you guys do with this. Originally these are nikasil coated. He tells me he has a shop that recoats them. Or should I have a steel sleeve put in? Whos the "go to guy" to send this thing out for machine work?

Or should I pass on it and keep looking?

The motor is a 250 VMax SHO.

(I posted this on the "porkchop build thread" earlier, but wasn't getting any responses, so figured I would post in the higher traffic Technical Discussion section)

Blake

**Capt.Insane-o** · 12-08-2020, 05:04 PM

clean it with some muratic acid and see what happens.

**slim95** · 12-08-2020, 05:12 PM

Southern Marine and Machine out of florida, Found these guys on facebook and he has tons of videos in his machine shop sleeving these yamahas

**David - WI** · 12-08-2020, 05:15 PM

If it's all 6 you might as well have Millennium or US Chrome strip it and re-plate? Or not?

**Dave S** · 12-08-2020, 05:56 PM

I want to close my eyes and grit my teeth........Find a better deal.

**InjectorService** · 12-09-2020, 09:59 PM

Originally Posted by David - WI

If it's all 6 you might as well have Millennium or US Chrome strip it and re-plate? Or not?

This is the option the seller suggested. Have you used Millennium before? He was going to get me a quote.

**InjectorService** · 12-09-2020, 10:02 PM

Originally Posted by slim95

Southern Marine and Machine out of florida, Found these guys on facebook and he has tons of videos in his machine shop sleeving these yamahas

Ill check them out. I have heard of guys putting steel sleeves in them. What do you guys with plated mercs do? Sleeve em? Junk em?

(sounds like Dave might junk em!

)

Also not sure about the acid, Ive used it before to take aluminum off with good success. The seller says it is definitely pitted, and according to him he does a lot of this sort of stuff. I mean I could just buy it and play with it myself to see what I can accomplish.

**David - WI** · 12-09-2020, 10:14 PM

Originally Posted by InjectorService

This is the option the seller suggested. Have you used Millennium before? He was going to get me a quote.

The reason I said that is that to re-nikasil one cylinder you have to strip them all and re- plate them all, so it's usually cheaper to sleeve one but if you have 3 or 4 bad ones re-plate is probably cheaper. But Dave & thrones guys do more of these I ever will.

Either US Chrome or Millennium... they do them all the time.

**Stoker boy** · 12-10-2020, 08:25 AM

Originally Posted by David - WI

The reason I said that is that to re-nikasil one cylinder you have to strip them all and re- plate them all, so it's usually cheaper to sleeve one but if you have 3 or 4 bad ones re-plate is probably cheaper. But Dave & thrones guys do more of these I ever will.

Either US Chrome or Millennium... they do them all the time.

Dave is correct, if you do send it to be re-plated make sure and use stainless bolts on all the thread holes the process eats some of the threads out of the aluminum.

**racervboat** · 12-13-2020, 11:09 AM

nicasil plated cyl for a 4 stroke.Interesting ?

**David - WI** · 12-13-2020, 11:38 AM

Originally Posted by racervboat

nicasil plated cyl for a 4 stroke.Interesting ?

We were buying aluminum bore, dual-bearing "industrial" Briggs motors, boring them 0.140" over and having them nicasil plated back in the 90's for methanol powered go-karts.

**Dave Strong** · 12-13-2020, 12:32 PM

With the cylinders looking that way a guy has to wonder what crank and bearing surfaces look like.

Dave

**InjectorService** · 12-13-2020, 09:49 PM

Yeah.... I'm starting to wonder if I will pass on this mess. I "think" my crank is ok in my motor. Weights are a little beat up, but I'm sure we can work around that, as long as its not bent, so I'm not super concerned about that.

He did chop the price in half if I take it as is though, so.....

These blocks are so hard to find, and finding a 2016+ is even harder. They changed some of the cooling system/routing from what I understand.

**Chaz** · 12-14-2020, 09:40 AM

Originally Posted by racervboat

nicasil plated cyl for a 4 stroke.Interesting ?

Mercedes and Mahle developed Nicasil in the 60's . Porsche and Benz still use it to this day. Biggest drawback with using it on four strokes is todays oil doesn't have the sulphur and zinc that it once did.

**Dave Strong** · 12-14-2020, 09:52 AM

Originally Posted by Chaz

Mercedes and Mahle developed Nicasil in the 60's . Porsche and Benz still use it to this day. Biggest drawback with using it on four strokes is todays oil doesn't have the sulphur and zinc that it once did.

I still say the Mahle Nicasil was better than the US chrome stuff.

Dave