F300 rebuild - resleevng the block

[choogenboom]

I am rebuilding a F300 that appears to have failed because the nikasil cylinder plating failed. That in turn lead to excessive blow by which the F300, which runs _very_ cold by design, could not flash off. The blowby was confirmed with leak down tests. That lead to fresh water accumulation in the oil which lead to lots of badness. The shit hit the fan when 3 of the 4 camshaft seals failed because their springs rusted after which the engine blew 4 of its 6 quarts of oil out the seals and I never got a low oil pressure warning. So I have some questions:

1. Has anyone ever converted the F300 4.2L block from sleeveless to sleeved? If so can you share details? I have been emailing with both Melling and LA Sleeves. LA Sleeves has a sleeve made for this block but I ended up ordering a similar sleeve from Melling, the CSL1149, since they were in stock. Googling shows many people converting from nikasil coated to sleeved on various mercury racing engines but I can't find anyone that has done it on this block.
2. Has anyone else experienced similar failure to mine?

[boscoe99]

Been involved with the Yam 4.2 liter blocks since they were introduced. First time I have heard the word nikasil as the coating that Yamaha flame sprays onto the cylinder walls.

Have never heard of the 4.2 block being bored out so that sleeves can be installed. If Melling and LA Sleeves has a sleeve for the 4.2 liter block it would seem they would be the ones that have a procedure to convert the block from a flame sprayed sleeve to a pressed in sleeve.

If the pressed in sleeve reduces the displacement of the block, how is that accommodated for by the ECU?

I have heard of the Yamaha flame sprayed cylinder liners being scrubbed off. In the early days it was erroneously known as "plasma peel".

There are companies that will strip a flame sprayed liner and respray it.

[boscoe99]

The bore of the Yamaha 4.2 liter block is 3.780".

The ID of the Melling sleeve is 3.736". The wall thickness of the Melling sleeve is 0.094". Gonna be quite a cut into the Yamaha block so as to fit that sleeve.

[choogenboom]

boscoe99 thanks for your feedback.

Melling says sleeve wall thickness has to be .060 or better. The LA Sleeves solution is a 1/16" (.0625) sleeve wall. 0.242 is the stock thickness of the block between adjacent cylinders. If we bore the current 3.78 to the new sleeve CSL1149 with OD 3.9265 that leaves 0.1015 metal thickness between cylinders and when bored to 3.78 the sleeve wall thickness will be 0.07325 which satisfies the 0.060 minimum sleeve wall thickness. Melling calls for a 0.003 interference cold press fit. Like you my main concern is how much block is left after boring for the sleeve. I am hoping its enough. I think the highest risk will be cracking the cylinder wall at the skinny spot when pressing in the new sleeve. Once the sleeves are in the forces should equalize.

The displacement stays stock as the new sleeve is bored out to the stock 3.78 bore. I plan to reuse the old pistons.

"plasma peel" is likely also known as nikasil flaking. I am pretty sure that's what happened to my engines and googling shows it was not uncommon in mercury racing blocks. Yes, I have twin 300's and both failed the same way. Same vintage, same failure . They replaced a pair of 2004 F225's and I am pretty sure you know the story on that engine. Maybe the same guy was in charge of the exhaust coatings on the 225 and the cylinder plating on the 4.2? I remain a loyal Yamaha fan but they have not made it easy for me.

[choogenboom]

To the forum moderator:

Why is my "join date" Sep 2022 (as in now) and I have 32 posts already? I have been a member here for much longer. Today I had to use the forgot password link to get access to me very old account. The forum remembers that I have 32 posts but forgets that I joined way back when. When I look at my post history I see only the ones I made today.

Also, one of my posts says "unapproved" and the subject has to do with a particular type of crankshaft bearing. Hint, they are not journal or crankpin bearings. I cant use the exact bearing word since I am pretty sure its interpreted as a salacious word and will get this reply labeled as "unapproved" so I will describe it. I handles the vertical loads of the crankshaft. Prop shafts also have such a bearing although they take a much greater load than the crankshaft version of his bearing. Hope this is enough information to decode the bearing I am referring to? Anyhow if the moderator is reading this can you please approve my post? I promise its OK. And maybe reduce the pessimism setting the AI uses to reject posts.

[99yam40]

if you think that is bad some of mine show up as I just joined every time I post also, do not worry about the little stuff

[boscoe99]

Have you thought of having the block stripped of its present lining and then being resprayed?

[boscoe99]

This site has it nuances. If a post says unapproved just be patient. It will be.

99yam is brand new member with 14599 posts. Pretty impressive. His keyboard must be smoking.

[choogenboom]

Have you thought of having the block stripped of its present lining and then being resprayed?

Sadly in my quest to find a solution I went down a path that went like this:

1. both engines have excessive blow by
2. I sometimes ***** for 7 hours straight at 1400 RPM or less
3. I never use ring free
4. the engines run cold by design(T-stat opens at 126F/52C ... I have NEVER heard of a 4 stroke run this cold, but thats a topic for another post)
5. excessive carbon build up may have caused stuck rings causing the blow by
6. I tried all the usual secret sauces to decarb the rings, soaking in kroil for days, soaking in seafoam for days, spiking the last 5 gallons of fuel in the tank with a overdose of ring free.
7. Nothing changed the blow by numbers so I went all in and tried pickling the worst cylinder with vinegar overnight. Big mistake and a long winded answer as to why sending the block out to be replated is not an option. That cylinder is too far gone to replate. Unless I bore it over and can find a non-oem oversized piston? Besides which google reports more than a few people that tried replating, many with success, but some failed in hours and had to be replated again. Consensus was nikasil might be good for weight reduction but does not age as gracefully as good old fashion cast iron.

Did you know a new 4.2L block is $3800 in the US but only 2000 euros in Norway? So less than $2K. I feel like the Japanese are sticking it to us in the US. I do feel like Yamaha has some explaining to do about why I have two F300's built at the same time both with the exact same nikasil plating failures at 1200 hours when so many people report getting from 3000 to 5000 hours from this motor.

[choogenboom]

Good lord (4 letter name of a popular deity that rhymes with Ford in case it gets starred out) I cant use the 5 letter word whose definition is using your motors to move slowly through the water while pulling fishing lures and rhymes with s*****?! I feel like Alice in wonderland.

[choogenboom]

And it appears I cant go for a s***** in the woods either. The AI bot that is sensoring (deliberately mispelled so I can get it past the sensors ) these posts needs to chill. In my most humble opinion.