Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

[mokaction]

engine is J225TXCUB..

Well for all you that have been following my threads, I have been having major problems with my engine. Tried to take it out X-mas eve, and engine would not idle.

I have replaced all the ignitions and tested weeks ago and all is working. So retested and all is still good.

Primer ball was going flat so I went through all the fuel lines and did a pressure check and I was getting erratic readings on my fuel line pressure at 3 to 5 psi at idle. So took the boat out of the water and did a compression check.

cyl 1=90 2=30 3=90 4=90 5=90 6=90

So I took off the head on the port side and check the cyl, found out that pieces of the rings was broken off in cyl 2. Also I was finding parts of ring matterial on cyl 4.

Question how come compression was good in cyl 4 yet, there was a broken ring in it?

I will be taking off head on starboard side today. Will keep you guys updated. Looks like a rebuild.

Question What can cause the Rings to brake like that?

I will doing a complete rebuild next month.

Larry

 

[reeldutch]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

could have been running lean.

didnt you mention a flat primer bulb?

thats caused by a fuel flow retriction (Vacuum) and leans out the fuel to air ratio.
why only 2 and 4 im not an expert on this.
could be temp related sets of preignition.
lean fuel will burn hotter. may be the 2 cylinders were warmer to begin with.
or the carbs from nr 2 and 4 cylinders where leaner. Clogged yet??

before you rebuild it make shure you find the cause.

 

[mikesea]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

maybe the ring piece in 4 came through the ports from 2

 

[WillyBWright]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

Too late, but if you were able to redo the compression test, you might have seen that #4 took more stokes to come up to compression. If one ring broke and the cylinder wall is still good, the second ring will still seal. Or a chunk of ring migrated down from #2 like mikesea suggested.

 

[mokaction]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

Cyl 2

Thermstat Gasket

Corrossion?? What causes this??

Thanks,

Larry

 

[mokaction]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

Sorry, Here is 4 cyl.. As you can see it is dented up really bad at the exhuast part of the piston.

Larry

 

[Solittle]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

Bet you run in salt water - - that is the corrosion you are seeing. Fresh water flushing after every use will reduce this somewhat.

 

[mokaction]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

Solitle,

Ya, I purchase this engine just 2 mth ago. So didn't take the head off to look first. I should have done that, but forsight is not what we always think. Well I am starting the dismantaling to get ready for the rebuild. Just wanted to share this with others.

Larry

 

[mikesea]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

FYI,Looking at the block picture,at position * oclock,you have some serious corrosion issues,leaving little of the original alum casting,you better check ALL the waterpassages around the cylinders,the block may need so much work ,it might not be worth rebuilding,the area I'm seeing leaves little surface for gasket sealing,if you have other cyl. with like or worse issues have a shop look it over for you before proceeding if your intent is doing the work yourself. They do seel flanged sleeves that repair the problem,however,if too many are bad,you might be better off looking for a better block.

 

[mokaction]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

Mikesea,

Thanks for the FYI, Ya, was able to scrap off some of the corrosion, really bad, but still looks good enough to rebuild, I will be taking it to the machine shop next year on the 2th.

Also is there another way to get the corrosion off?

Larry

 

[Dhadley]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

Are you taking it to an automotive machine shop or a marine machine shop?

 

[mieyk]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

looks more like crushed bearings than rings.A BAD DAY OF FISHING IS BETTER THAN A GOOD DAY AT WORK.

 

[mokaction]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

Got the motor a part. have ring every where, also in the in take manfold. You know also check 4 cyl and rings are OK, pieces of 2 cyl ring was in 4 cyl.

Also what is a good way off getting rid of the corrosion, beside scraping it off??

Larry

 

[Kajun37]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

have it bead blasted...

 

[mokaction]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

cool. Ya, that sounds grea Kajun bean or sand blasted. That will work.

Dhanley,

I will be taking it to Nick at http://www.lasleeves.com Really great machinist. I have had work done there in the past. They also releeve cyclinders if they need.

Larry

 

[mokaction]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

http://www.lasleeve.com this is the right url. other one is bad..

Larry

 

[Dhadley]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

Yep, they do good work. Nice guys.

 

[mikesea]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

thats the place,give us the price on sleeving by them ,curious if the guys in south Fl.are hi or low. surely la sleeve got to be one of the best.

 

[mokaction]

Re: Broken ring in Cyl 2 and Cyl 4. Why is compression still good in Cyl 4?

Mikesea,

Ya, I have worked with them a couple of times, and it is worth the drive over. I live in Ventura, Ca. and they are in Santa Fe. About 60 to 70 miles away. There are local guys, but I don't trust them. Nick is the best. Also takes about 7 to 10 days turn around. On Re-sleeving takes about a month, but worth it.

price is on the price sheet on the web site. also runs about $200 buck to resleeve, also do a lot of racing engines too.


Larry