Johnson 60hp 92 Rebuild help

[smith_daniel]

Hi guys, i burnt out a piston following a blocked carb.

I have broken the engine down and replaced the piston, honed all three cylinders and replaced the rings on all three pistons.

I am holding back on putting the engine back together as im not sure what to do regarding prep for restaring it / timing etc etc

Do i just put it all back together as it was, using plenty of 2stroke oil as lube for initial start, then just crank it until it starts or do i have to do something before hand??? Obviously i have rebuilt the carbs so it doesnt burn out again.

Is there a method for getting the timing etc right, and can i completely ruin the engine if i get this wrong????


I have no real experience of boat engines, and would really appriciate some help. i did the tear down and replacement without any help (Although i did ask, i just didnt get a reply... am i doing something wrong?)

I have some pics to load up too if anyone can help with that.... sorry for being such a newbee, but you gotta start somewhere!

Thanks

Dan
smith_daniel@hotmail.co.uk

 

[gm280]

Re: Johnson 60hp 92 Rebuild help

Actually I am doing basically the same thing with an old Johnson 40 HP engine from the 1976 era. While I didn't have any blown pistons, I am changing the rings and have the entire engine completely disassembly and blasted to the metal and primed now waiting for the weather to settle to paint and reassembly. I too will be wondering some of the same things. I'm sure you used some type assembly lube on the needle bearings and such during reassembly. As to how you initially start her up again is one of my interests too. The pros should have a few suggestions on here, so I’ll watch as they reply. The lync and sync is needed to make the engine perform correctly and you could search for those issues for your engine as a place to start with the timing and carb setup.

 

[smith_daniel]

Re: Johnson 60hp 92 Rebuild help

Thanks, Ill search the "link and sync" see what that throws up!

When i figure this site out ill get some pics up! not for educational purposes, but i always find seeing an engine in various stages of being broken down helps fend of the utter panic of starting and then thinking... WHAT HAVE I DONE! hahaha

Hopefully ive passed the half way stage and can finish tomorrow, as planned HAHAHA, and be ready for the first summer of owning my own boat and not being a tag along with everyone else!

 

[Willyclay]

Re: Johnson 60hp 92 Rebuild help

You might want to read the thread at the link below before re-assembling your motor. Good luck!

http://forums.iboats.com/johnson-ev...e-know-what-pinholes-piston-skirt-594792.html

 

[smith_daniel]

Re: Johnson 60hp 92 Rebuild help

Hi guys,

Found a friend who works in the marine engine trade, v reputable firm, to help me rebuild the beast... i thought my worrys were over, but it turns out that is NOT the case!

When i removed the pistons, crank etc etc i laid it out all neatly and in order on a clean dirt free desk, perfectly in order of removal!

When the guy turned up to help he didnt keep everything in original pairs, he didnt put the caps on in a specific direction and basically over tightened the con rod bolts. He grabbed whatever came first and put it on.... i didnt know any better and thought he knew what he was doing!

The result, bearings foul on the con rods as the rods very slighty flaire inwards. this was only noticed once he tried to spin the crank and found it wouldnt move. He then loosened the con rod bolts and tried again which helped a bit, but then there was a clicking noise. (bearings hitting the conrod flair)

He then bailed on me and went to watch the football leaving me in the ........

I stayed and tryed to work out what was wrong.

(reading the manual i already had, and tried to consult with whilst he was doing the work, but was told to "put that thing away") I now know that he should have mated original pairs and should have matched the original bearings and ensured they were facing the correct way!!!! as i had liad them out!!!!

My problem now is the bearings are damaged, meaning ?120 + for replacement sets. the other problem is that i have no idea which cap goes with which conrod!?!?!?!?????

I looked at prices to replace the three con rods, but at over ?150 EACH i cant afford it!

Looking more closely at the rods off the engine, the surface has flaired in slightly from the over tightening / dont match up correctly and are far from being a perfectly smooth surface, which catches the bearings on rotation and causes the friction and "clicking" noises.

What the hell do i do now???

How can I use the existing rods and caps without buying new ones?? Can i try and rematch the caps to the rods, as best as i can, then somehow remove, file, sand, hone, excess material that may foul the bearings????

Im not a happy man at the mo, everything i have done, with nothing but a bit of common sense and patience, has gone right and as it should have been. Along comes a "trained" marine technitian and he arses the whole lot up, and in fact puts the engine in a worse position financially then the orginal burnt out piston!

Please help guys, I really appriciate its a hard one to comment on, and any type of comment regarding non industry standard fixes will be frowned upon, but i really cant afford to replace the rods, and really need your advice! If i cant sort this issue ill have to sell the boat to recoup losses and be in a worse position then before this boating fantacy even existed!

Thanks in advance

Dan (smith_daniel@hotmail.co.uk)

 

[Chinewalker]

Re: Johnson 60hp 92 Rebuild help

Personally, I think the rods are toast. Being torqued on the wrong rods with improper alignment makes them paperweights. You can find used rods for a lot less than new. I am rebuilding a 1988 and it had a bad rod and crankshaft, in addition to a burned piston. I found a good rod and crank on eBay for decent prices. Just match up the casting numbers...

 

[trendsetter240]

Re: Johnson 60hp 92 Rebuild help

Pull everything apart again and lay the crank and bearings all out on a table for inspection. The bearings themselves are interchangeable between the connecting rods so it doesn't matter that they weren't put back in the same rods. However, the caps being torqued down on the wrong rods does matter.

You can match up the caps though it will be a little harder now that they've been installed incorrectly once. Put all three out on the table and try to hand fit the caps on the rods until you find the right ones. They only go on one way and with one rod. The mating surface must be completely smooth. So smooth that you can run your fingernail over each joint and not have it catch.

After you have matched the caps and rods check the inner surface of the bearing race on the connecting rod. If it's flared in then you can't repair it and it needs to be replaced. Don't try to get by with a damaged bearing race, all your hard work will be for nothing when that bearing comes flying apart at 6000RPM.

 

[smith_daniel]

Re: Johnson 60hp 92 Rebuild help

Thanks for taking the time to reply guys! Ill get onto ebay and the like to try find suitable 2nd hand parts.

fingers crossed!

With all the hassle and all the agro that has come with this boat im actually quite enjoying pulling it appart, learning about how they work and how to repair and put it all back together.... the only obvious downside is the financial cost! Parts are crazy money! CRAZY MONEY!

its 22yrs old... thought people would be giving away stock to simply clear it from the shelf!

Once again, your help is invaluble and very much appricated!

Will keep you all updated with the trials and tribulations, and hopefully.... a positive final result!

Dan

 

[gm280]

Re: Johnson 60hp 92 Rebuild help

I see you were trying to do it the correct way with lining up things up in a sequence as you removed them. A few things for the next engine project to do. As you remove anything to clean and rebuild, take lots of pictures (digitals are very cheap to snap alone the way) AND mark things like the rods and caps. That way IF you somehow get them mixed up (or in your case have a know-it-all...NOT) help you out, you will know exactly how to reassembly it again. And you equally did the right thing with trying to follow the manual with the reassembly. Anybody that tells you to throw the manual away, you should show them the door... I hope you do find other parts for the damaged parts and get it running also. It does give you a great feeling to know you did it yourself... You may even find out that once you look at the rods and caps you will figure out which one fits the correct part. Have a great day...