Rebuild Success!!!

[BigTerp]

Had alot of questions answered regarding rebuilding a 1994 Johnson 50/35 and making it work on my boat in a previous thread. Thanks for that!!
https://www.tinboats.net/forum/viewtopic.php?f=48&t=28765

I can finally say the rebuild was a success!!! It went alot smoother than we planned. I'd say we have a total of about 16 hours in it. We replaced pistons, had cylinders bored out to .030 over, new water pump, new impeller and all new gaskets. There were a few other odds and ends that needed replaced, but that's basically all that we needed to do. I'm pretty fired up that she runs as good as she does. Just need to get a transom riser worked out and it'll be ready to mount to my boat.

Didn't get alot of good pictures, but I'll post what I have.

New pistons

Water pump and impeller replaced and jet pump assembly re-assembled. Also sharpened the impeller and checked for clearance. Only needed two shims above the impeller to get proper clearance.

Cylinder heads bored out and cylinder head re-surfaced. The machinist did an excellent job.

Powerhead reassembled and installed.

That's all the pictures I got. Should have taken more. We did all of the little things during the rebuild as well, including cleaning carbs, replacing fuel lines, new fuel filter, etc.

Just a short video of the test run. Needs a little fine tunning, but at this point everything is good to go.....FINALLY!!
[youtube]RCLBgYI8zEQ[/youtube]

 

[Johny25]

Nice job Terp, that motor should last your lifetime now =D>

 

[BigTerp]

Johny25 » 16 minutes ago[/url]"]Nice job Terp, that motor should last your lifetime now =D>

I'm hoping so!! All the credit goes to my buddy on this though. I learned ALOT during the process, but for the most part I just did what he told me to do. He really knows his way around engines, especially 2-strokes. He routinely rebuilds dirtbike engines. I think he's done over 20. I was impressed with his knowledge and how well everything turned out. Super excited to get it on my boat!!

 

[J Hartman]

awesome job, rebuilds are a pain, but worth it in the end... ( usually )

 

[BigTerp]

J Hartman » Yesterday, 6:13 pm[/url]"]awesome job, rebuilds are a pain, but worth it in the end... ( usually )

Thanks!! It wasn't nearly as bad as I thought. Things went really smoothly.

 

[J Hartman]

Have you run this motor on the boat yet? I'm curious if you can tell a big difference in performance now.

 

[BigTerp]

J Hartman » September 7th, 2013, 7:26 am[/url]"]Have you run this motor on the boat yet? I'm curious if you can tell a big difference in performance now.

Not yet. My buddy and I have both been busy. He's away the rest of the week, and I'm gone all this weekend. Planing on dry fitting the motor next week so we can get good measurements of the transom riser we need to fabricate. We'll get that fabricated and the motor installed hopefully next week as well. We bought this motor needing rebuilt. So I won't be able to tell any difference in performance. But I'm sure it'll be slightly better than the 1965 Johnson 5hp I currently run :lol:

 

[Tbradley]

Keep us posted on the performance on your 50/35. I'm looking at a 2008 yamaha 50hp 2 stroke that I'm wanting to jet, just looking to see what kind of load it will haul.

 

[BigTerp]

Tbradley » Yesterday, 9:00 pm[/url]"]Keep us posted on the performance on your 50/35. I'm looking at a 2008 yamaha 50hp 2 stroke that I'm wanting to jet, just looking to see what kind of load it will haul.

Will do. I'm cutting my aluminum tonight for the transom riser. Depending on when my buddy can get his welder setup for aluminum, we should be installing the motor this weekend or early next week. Will give it a few days for the 5200 to cure, then hope to get her wet late next week.

 

[Tbradley]

BigTerp » 18 Sep 2013, 08:35[/url]"]

Tbradley » Yesterday, 9:00 pm[/url]"]Keep us posted on the performance on your 50/35. I'm looking at a 2008 yamaha 50hp 2 stroke that I'm wanting to jet, just looking to see what kind of load it will haul.

Will do. I'm cutting my aluminum tonight for the transom riser. Depending on when my buddy can get his welder setup for aluminum, we should be installing the motor this weekend or early next week. Will give it a few days for the 5200 to cure, then hope to get her wet late next week.

Have you ran her yet?? I'm so on the fence on buying a Yamaha 50hp I can't stand it!!

 

[BigTerp]

Tbradley » Today, 10:11 am[/url]"]

BigTerp » 18 Sep 2013, 08:35[/url]"]

Tbradley » Yesterday, 9:00 pm[/url]"]Keep us posted on the performance on your 50/35. I'm looking at a 2008 yamaha 50hp 2 stroke that I'm wanting to jet, just looking to see what kind of load it will haul.

Will do. I'm cutting my aluminum tonight for the transom riser. Depending on when my buddy can get his welder setup for aluminum, we should be installing the motor this weekend or early next week. Will give it a few days for the 5200 to cure, then hope to get her wet late next week.

Have you ran her yet?? I'm so on the fence on buying a Yamaha 50hp I can't stand it!!

Yeah, we actually ran it last night. Not going to help you any though. The motor is running/stuck in S.L.O.W. mode, at least we are pretty sure that's the case. It's a failsafe system that keeps the motor running at 2500 rpms even at WOT. Suppose to go into S.L.O.W. mode if the engine overheats or if the oil injection system isn't function, which we don't use. Need to do some trouble shooting to see what is going on. Won't get to that until tomorrow or Thursday, then hopefully will be able to take it back out Thursday evening. I'll be sure to let you know how it runs with my boat and get a video or two once we get it squared away. We are hoping if we unhook the VRO (oil injection system) wiring harness it will solve the problem. But it could be a bad temp switch, bad diode or even bad power pack. Won't know for sure until we can get the ohmeter on everything. Last night it topped out at 8.4 mph :shock: Couldn't get up on plane. Hoping to at least have a diagnosis, if not solved, by Thursday. Dissapointing, but other than the motor not wanting to open up the whole way, everything else seems good. Could've been worse I guess.

 

[BigTerp]

="Tbradley » October 1st, 2013, 10:11 am
Have you ran her yet?? I'm so on the fence on buying a Yamaha 50hp I can't stand it!!

Jets were clogged. We tore apart the carbs over the weekend and the jets were pretty nasty, especially the lower one. Cleaned them up real good and the motor ran much better in a barrell in my driveway. My buddy took it out on Sunday and said it ran like a top. Got 20mph with him and a passenger. I was expecting closer to the mid 20's though. But 20mph will certainly do. Said it planned easily and stayed on plane down to about 12mphs. I finally have the time to take her out for myself tonight. I'll report back with what I think.

 

[mphelle]

I wouldn't be concerned about speed until the engine has been broken in, lots of opinions on this but I like to give it at least five hours of varying rpm to seat the rings before going to sustained wide open throttle. My Yam 50/35 used the same pump/impeller, and would push a 1648 with 2 big guys and gear to around 25mph at 5400rpm. Once the motor is broken in and showing good compression you can look at setup to find more speed.

 

[rockdamage]

The cyl gets no oil if the jet is clogged ...... not a good way to break in an engine. If you ran it for any period I'd pull the head and check the bore. Head off any future problems.

The troll.

 

[BigTerp]

Thanks guys.

Before realizing the jets were clogged, we ran the engine for maybe an hour total. Most of that was at idle in a barrell. Think I should still take a look see and make sure the cylinders aren't damaged?

Finally had the chance to take it out by myself last night. Ran GREAT!! No issues at all. I got 26.3mph going up river. Planes easily, and handles well. Steering a jet powered boat will take some getting used to though, but I like the way it slides while turning Following my manuals break in instructions for the first few hours. It was hard to stay off the throttle last night, but I forced myself to only keep it wide open for short periods. We got about 2 hours in it so far. Plan to take it out again over the weekend for some more break-in time. But man is this thing a pig on gas!!!

I have no idea what my hull weighs, but it's a Tracker Sportsman 1648 with 2 group 27 batteries and I'm estimating about 150 lbs of aluminum (probably a high estimate). I'm 255lbs and had no gear in the boat when I ran it last night. I'm more than happy!!!

 

[mphelle]

Much improved report from your last, I wouldn't pull the head, just continue what you're doing and maybe do a compression test in a few hours.

 

[BigTerp]

mphelle » Today, 6:15 pm[/url]"]Much improved report from your last, I wouldn't pull the head, just continue what you're doing and maybe do a compression test in a few hours.

I was thinking the exact same thing. Cylinder is already at max bore after our rebuild. Not much we're going to do anyway if the bore is scratched or something, other then a new cylinder. Just planning on taking it easy during the break in period. Hopefullly it keeps running as well as it did last night!!!

 

[BigTerp]

Keep us posted on the performance on your 50/35. I'm looking at a 2008 yamaha 50hp 2 stroke that I'm wanting to jet, just looking to see what kind of load it will haul.

I know I might be a little late, but I've been working out a few hiccups with my setup. Haven't had it out in almost 2 weeks. We had it out 2 Saturdays ago while duck hunting and it ran like crap again. We quickly tore apart the bottom carb because, as we suspected, the needle valve was stuck. Once we unstuck it, it ran wonderfully again. With myself, one other person, 2-1/2 dozen decoys and other hunting gear it seemed to run and plane just as well as without any gear in the boat. Didn't GPS it though. We finally have the time tonight to install new needle valves in both carbs, which should solve the problem.

We took it out again the Sunday after we duck hunted and had zero issues with the motor. With myself (250 lbs.) my buddy (200+lbs.) 8 gallons of gas and no gear we easily got 25+ mph up river. Was able to run in about 5-6" of water (rough estimate, it sure seemed like less than that) on plane. Boat planes quickly and stays on plane down to a little less than 3/4 throttle. We ran further up river than I'd ever thought we'd be able to go. It was ALOT of fun picking my lines through the riffles and just zooming right through. Once I got a feel on how to read the river, I had my buddy white knuckling his seat a few times :LOL2: Once we got an hour or so up river and about halfway through our gas my control box locked up on me. We tore it apart and it had broken a tooth on the main cam . Since I've never owned a remote controlled outboard, I didn't realize how tight the control lever should be (now I realize it was WAY to stiff). It was caused my a bad/stiff control cable. Got it back together and working but couldn't put it in reverse due to the missing tooth. I haven't had it out since. I got a new cam and cables put on this week. Doing the needle valves tonight and hopefully will be back out again this weekend. My wife wants to come along and do some fishing, so I'll try and get her to take some videos to give you an idea of how it runs.

If this helps any, I'll list what I have on the boat to give you an idea of how much of a load I'm running.

-1995 Tracker Sportsman 1648 (no idea on hull weight)
-2 group 27 batteries mounted under bow deck
-Bow mounted trolling motor (older motorguide pro series 41)
-Estimated 150lbs. of aluminum (probably a slightly high estimate)
-6 gallon gas tank (extra 5 gallon can that comes along on longer runs)

 

[user 6672]

You'll have the bugs worked out just in time for spring

It may seem like one thing after another but it will be nice when its as bug free as a boat can be

You have to be right at max weight for a 50/35 on a 16...

 

[BigTerp]

Canoeman » Today, 7:17 am[/url]"]You'll have the bugs worked out just in time for spring

It may seem like one thing after another but it will be nice when its as bug free as a boat can be

You have to be right at max weight for a 50/35 on a 16...

Hopefully the bad cable and needle valves will be the last major bugs we have to deal with. It's been a steep learning curve for me, but I'm actually glad to have run into a few of these problems. For one, it taught me to figure out from sight/sound/feel what is going wrong with the motor and how to address it. It also caused me to add a few more tools to the boat so I should now have everything I need to tear into the motor if it gives me problems again while on the water. For example, when we had to take the carb apart it was nearly impossible to do with a socket, but we managed. Now I have a few wrenches in the boat that'll make getting into those tight spaces MUCH easier.

I'm not sure about weight. Like I said, with 2 people and max hunting gear it seemed to run just as well as without any gear. The real test will be when we add another person or 2 during duck season.