2 stroke rebuild

[79 Jimmy]

Well I'm about to start my winter project. I bought my first boat this past summer and can't beleive I waited this long. It's a 17 foot Double Eagle and it had blood on the deck every time out. However the engine is tired, I knew this when I bought it but was hoping to get a season or two out of it but its not to be. It's an 86 Johnson 150. Just wondering if anybody has rebuilt one of these old crossflows and might be able to offer up any advise/tips/things to watch out for. I've done lots of dirt bikes as well as the 383 stroker in my truck so engines are not new to me but outboards are. My first question is about the crankshaft, As they run in roller bearings are they generally reused as is or polished or....? Currently the engine runs ok but I don't have a lot of confidence in it. Compression is low so I pulled the heads, a few cylinders and pistons are scored but no broken rings yet. .020" overbore will clean it up nicely.
Any input you good folks can offer would be much appreciated
Maybe I should do a photo diary/theard about the progress if anyone is interested...

James

 

[Kildonan]

If you have time to document and show it in posts as you progress, that would be wicked. I love those kind of threads.

I know dick all about rebuilding engines so have nothing to contribute but it's always fun to watch and learn.

 

[sly_karma]

FWIW, I do believe 85 is a looper not a crossflow. Good luck with the rebuild and don't forget to take pictures.

 

[79 Jimmy]

Well it took me a couple days but the engine is now disassembled. Snapped off a handful of bolts but expected that on a 27 year old outboard. also going to have to order a few parts from the midsection area as some of these parts required destructive dis assembly only one of which is no longer available. LOL. I took some pics for reference and I'll post them soon. FYI it's an "86 and definitely a crossflow engine. Time to order some parts, I was thinking of using www.boats.net south of the boarder for the oem Johnson parts unless someone has a better suggestion.

J

 

[NautiGirl]

If you need some hard to find Johnnyrude parts try http://www.seaworthymarine.ca/ in campbell river

 

[Fish Rider]

If you need parts too,I know a guy in Nanaimo. He helped me with parts on my rebuild in the year new. Pm if you need help!

 

[fshnfnatic]

Well it took me a couple days but the engine is now disassembled. Snapped off a handful of bolts but expected that on a 27 year old outboard. also going to have to order a few parts from the midsection area as some of these parts required destructive dis assembly only one of which is no longer available. LOL. I took some pics for reference and I'll post them soon. FYI it's an "86 and definitely a crossflow engine. Time to order some parts, I was thinking of using www.boats.net south of the boarder for the oem Johnson parts unless someone has a better suggestion.

J

I'd definately recommend boats.net for ordering new OEM parts. Have dealt with them several times,and they have
always impressed me.Prompt service,and even with the shipping costs,their prices can't be beat up here. As long as
your not in a big rush,they're the way to go. USPS Priority INT. shipping takes about a week from them. Not bad
concidering they are in Florida,which is about as far away from us you can get on this continent.

 

[beemer]

check with Bridgeview Marine , they have a load of old oem parts in the basement.

604-946-8566.

8550 River Rd, Delta, BC V4G 1B5.

 

[79 Jimmy]

Thanks guys. I'll definitely be making some calls. I figure I'm looking at about $5-600 in parts so if I can find some used ones in good shape I'm all for it. I'll be painting everything anyway. Pulled the crankshaft today which required a trip to the tool store as i didn't have a 5/16 12 point socket. It looks great, the pistons not so much. LOL. I'm really surprised this engine was still running without breaking some piston rings. Quite a lot of scuffing and piston rocking in the cylinder. The cylinder with the worst compression actually had piston material flowed over the ring preventing it from expanding against the cylinder wall.

 

[beemer]

love to see some pics!

 

[Dave S]

Are you going to sleeve the cylinder bore's to be able to use oem pistons, or you thinking about getting some oversize pistons? Cylinders currently plated? Fun project. Hope you have a heated and dialed shop for the winter months.

 

[79 Jimmy]

Yes Dave I do have a heated shop, I actually own a small CNC machine shop with my brother in law that we operate on the side. My plan is to bore the block myself then send it to Mongoose to hone the last few thou. I'm going to use + .020" pistons (already have them). The sleeves already in the aluminum block and can be bored up to .060" over. This engine predates any fancy coatings like nicklsil etc. it's just a cast iron cylinder.

 

[trendsetter]

Hey Jimmy 79, I've rebuilt a bunch of these motors over the years so if you have any questions I'd be happy to help where I can. My first piece of advice is to fully inspect all parts before you start buying new ones. The first step is to inspect the crank journals for any pitting or scoring. If they are damaged in any way the crank is junk and will need to be replaced.

If you need a new crank then things start to get expensive really fast. Also it's very difficult to tell if .20 over will be enough of a bore to remove the scoring. I've been down that path before and you should wait to purchase pistons until you know the size needed. Sounds like you missed that step so hopefully you get lucky! Often I've found that scoring like that needs to go to .40 over. In that case you will need larger pistons.

Mongoose is awesome, I've used them for all my rebuilds. They will hone the cylinders to match each piston so make sure you send the pistons in with the block when get them to work on it.

Best of luck, check that crankshaft. It's not worth all the cost and effort to rebuild only to have the bearings blow apart in the first 100 hours because of a scored crank journal.

Cheers

 

[Finished Business]

Time to order some parts, I was thinking of using www.boats.net south of the boarder for the oem Johnson parts unless someone has a better suggestion.

J

I have a better suggestion. Stay the hell away from BOATS.NET!!! Far far away.

I needed a new Yamaha carb, asap. Called boats.net. They had it in stock, great! Place my order, detail clearly in the original order on their website, a privately sent email, and a phone call, that I need it shipped next day air, and was happy to pay additional charges.
No problem they said, took payment, and processed the order. 2 days later, nothing, a 3rd day, and I call. Where is my part? Oh, the part was just processed and is currently awaiting shipping, ground shipping. Great! With a 10 day trip relying on this part, I start sweating. Grind a couple guys on the phone to remove the item from ground shipping and ship it next day. After going back and forth, them saying they cant do that once its in the system blah blah. I get my way...I mean, I paid for it! LOL.

So the part arrives, with 24 hours to spare to install and test the new carb. Luckily Trendsetter is a wizard with small outboards and had it back together in no time.

Happy, and giving BOATS.NET the benefit of the doubt, I go online to leave a good review of how they, although made a mistake, did everything possible to correct it. But I never got to the good review. Looking up boats.net I found endless bad reviews from customers. Literally endless. So I chalked them up to being a bad business to deal with.
BUT it didn't end there. 2 weeks later, I checked my credit card statement, and found someone in the area code of the boats.net facility in Florida had used the card number for 2 tickets to Europe from Hotels.com.

So ya. Stay far away from BOATS.NET. If not, you will likely regret it.

 

[79 Jimmy]

Thanks for the heads up guys. Trendsetter, I totally agree, I probably should have waited a bit to order the pistons but like you said I hope I get lucky! I'm not too worried but I guess its possible the worst cylinder wont clean up. We shall see. The crank looks very good, zero pitting no heat discolouration and just the faintest ghost image of where the bearing rollers may have sat on the journal for a while. It measures in spec. A quick polish and it should look brand new.
Finished Business-thanks for sharing your experience with boats.net, I will be doing a little more research as to where to source my parts. I think I'll wait till I get the machining done and start putting it back together before I order any more parts.
Just a quick question about the large nut that sits on the bottom of the steering tube. Its 1 7-8 and the manual says to discard it if you take it off, just wondering if that is totally necessary or if it can be reused with some loctite?

Thanks again guys, I really appreciate it!

J

 

[Dave S]

I've used Mongoose quite a bit back when I lived in Poco and rode motocross. They know their ****. Good luck with the build. And I'm wishing I had a heated shop over here in Vic to wrench on motors more. Enjoy the rebuild.

 

[79 Jimmy]

Worst pistons....

 

[79 Jimmy]

And the crank.....


A rod, I know it looks rusty but its just the photo....

 

[trendsetter]

Just a quick question about the large nut that sits on the bottom of the steering tube. Its 1 7-8 and the manual says to discard it if you take it off, just wondering if that is totally necessary or if it can be reused with some loctite?

I've taken those nuts off a few motors to swap the power trim / tilt brackets. I always re-used the nut so I dunno. If it's not damaged then I don't see why it couldn't be re-used with some Loctite.

Just curious, why is it that you're taking off the steering arm?

 

[79 Jimmy]

I'm just looking to disassemble to aid cleaning, sandblasting and repainting.

I tried posting some more photos of the process yesterday but I got a message saying they required approval so hopefully they will be up soon...

I've taken those nuts off a few motors to swap the power trim / tilt brackets. I always re-used the nut so I dunno. If it's not damaged then I don't see why it couldn't be re-used with some Loctite.

Just curious, why is it that you're taking off the steering arm?