Advice please, rebuild, used or new?

[rkhanso]

Bad news from the shop about my 1992 Johnson 2-stroke 90HP V-4 outboard. He said cylinder 3 leakdown test? is 50% and cylinder 4 is 25% (it may have been the other way around). He said 15% is the most you want to see. He suggested it may have been a thermostat problem but that's a guess.<br /><br />Anyway....What do I do? He said the last rebuild he did on one was around $2000. <br /><br />The boat it's on is a 1992 Glastron 17' Fish/Ski boat in pretty good shape, although normal wear and tear on the snaps, carpet, vinyl, etc.<br /><br />I was quoted $6340 for a new Yamaha 90 2-stroke with 2 year warranty (motor and controls) and was quoted $8000 for a new E-Tec 90hp (motor and controls). This dealer has no used 90 or 115 motors now.<br /><br />They said if I went used, I could still end up with a not-so-good motor. They suggested buying a used motor from a dealer and I may get a 30-60 day warranty.<br /><br />I'm pretty mechanically inclined (do own car maintenance, and have done some major mechanical work, but no engine rebuilding, and I have no specialized tools). Can I rebuild it myself?<br /><br />I'm in this dilema - I'm cheap (really cheap) but I like to fish and take the family out tubing and skiing.

 

[Dhadley]

Re: Advice please, rebuild, used or new?

If it were mine I'd like to know what caused the problem. What actually happened? Are the pistons scuffed? Hole burned in the top? Are the rings just stuck (possibly a good decarb could help?)?<br /><br />I'd think that before we go any further, we gotta know where we;re at.

 

[rwise]

Re: Advice please, rebuild, used or new?

how long has it been since it was decarboned? I would run some seafoam through it and test it again. just a thought

 

[funpilot]

Re: Advice please, rebuild, used or new?

After you run Dhadley's tests (compression, decarb, compression again, and then if needed take off the heads and peak inside) you might consider rebuilding the engine. You will need a torque wrench, normal wrenches, a model specific manual, sealants and loctite, a gasket set and some patience. A $50 engine stand is really helpful too. If you don't want to do the entire engine yourself, take the power head apart, strip it down as far as you can, and get a shop to inspect if for oversize bores, matching pistion size, and then rebuild and reseal the block. From there you could build the motor and set it up. If you've never done an engine before you could learn a lot by having a reputable shop assist you. They have the experience to let you know what is good and what is bad inside your motor. <br /><br />You can clean the carbs, fuel system, set the timing etc. with the help of the manual.<br /><br />With respect to the boat, if you've taken care of it, it probably will give you years of great service, so rebuilding an engine or getting a used one is probably a good idea. From my experience with my aluminum fish and ski, the flooring rotted out where the skiers came over the transom after each run. It was about 12 years old when I replaced that section of flooring! Something to think about...<br /><br />good luck,<br />funpilot

 

[BillP]

Re: Advice please, rebuild, used or new?

Now is a good time to learn simple 2 stroke outboard rebuilding. A good chunk of the rebuilt cost will hinge on whether the block is ok. Pull the heads and see what the cyls look like.

 

[rkhanso]

Re: Advice please, rebuild, used or new?

Right now, it's at the shop (Hannay's in Minneapolis).<br /><br />I did a decarb last year and ran seafoam in the last few fillups.<br /><br />The last time I had it out last year, it was getting hard to start, idled rough but ran wide-open really good. Since that's the case, I'd guess there's no major engine damage (holes in piston, etc - no really obvious knocks or other noises as far as I could tell)<br /><br />I've ruled out a new motor - they're just way too expensive. <br /><br />Can I rebuild this thing myself? With a little help from my friends (the iboats forum and the shop)? Remember, I have no special tools, other than a small torque wrench. Nothing to measure compression, leak-down test, etc.<br /><br />The shop charges $87/hour, which I've found out is pretty average. I don't want to start taking it apart, trying to do it and then having to pay the shop more to fix my mess.<br /><br />I asked the shop a few more questions. He looked into the cylinder (through spark plug hole) and saw scoring on the cylinder in the bottom piston. The trouble is only on the starboard side. He said when they do the work, they warranty it for 6 months from fishing opener and they go over it really well because of the warranty (replace water pump, impeller, thermostats, etc) for the ~$2000.<br /><br />If I do it myself, what kind of money am I looking in at parts? - then I need to consider the warranty and a knowledgeable person doing the work, instead of myself to do the complete "Cost Benefit Analysis." And, what is the realistic probability of a little better than average amateur mechanic like me successfully doing this repair?<br /><br />I did see tenkillermarine.com on the web - selling rebuilt power heads for $1500 with a lifetime warranty. Might that be a better option?

 

[Dhadley]

Re: Advice please, rebuild, used or new?

Scoring on the starboard side is usually coking damage. Not really a big deal to fix. Bore it and new pistons etc. The biggest thing is to change the set up so it wont happen again.

 

[rkhanso]

Re: Advice please, rebuild, used or new?

So, what kind of job is that - boring and new pistons? I can 'usually' follow directions, is there a better manual to get to accomplish this? What about the time required?<br /><br />And what needs to be done so it won't happen again?

 

[rkhanso]

Re: Advice please, rebuild, used or new?

It looks like pistons are going to be around $400. Extra parts....not sure what in addition to that.<br /><br />So, I think I'll just have the dealer do the work. If the parts are anywhere near $500-$700 and the rest of the $1300-1500 is labor/warranty/knowing it's done right, I'll err on the side of caution and let the shop do the work.<br /><br />I don't want to spend the time to fix what I think is the problem, just to have to take it all apart again if I missed something. Plus, there's that 3rd paycheck this month...

 

[rodbolt]

Re: Advice please, rebuild, used or new?

last V4 I built the parts and machine work was close to 1600. that included all new bearings one sleeve 4 new oversize pistons 8 rod bolts 4 rod bearings all main bearings BRP gasket set 4 wristpin bearing kits lower unit seal kit,water pump t-stats clutch dog, paint OMSpumpkit and recirc check valves all recirc lines and carb kits and fuel lines and filter. mostly a complete job. I also give a year warrenty if the failure was caused by a replaced part or improper assy. <br /> you may look into a reman block assy. then you just have to finnish the job. so if done properly 2000 is a low price. here in the salt pond takes 20 hours or so of labor. drilling broken cover and exhaust plate bolts and digging out diverters and such. but like Dhadley says, check you set up and try to find out why it died to start with or odds are good it will do it again.

 

[rkhanso]

Re: Advice please, rebuild, used or new?

The shop said all 4 cylinders were scored - some worse but all scored. He thought it would be due to lack of oil problem. The alarm horn did go off a couple times last year and I put a new pump on last year to fix a wide open engine dying problem. I guess it must have been too late. I replaced the pump with a standard pump and mix the fuel now.<br /><br />I should be able to pick it up late this week or next, according to what they told me when I dropped it off. <br /><br />What would be the break-in procedure for a rebuilt 2-stroke outboard 90hp?

 

[rkhanso]

Re: Advice please, rebuild, used or new?

I got the boat back a while ago. It was $1900 for the repair. <br /><br />It starts and idles much better. I think there is a bit of a miss at 2K rpm, but I may be wrong - maybe it's normal for a 2-stroke?<br /><br />Anyway, I almost have the 1st tank of gas burned up so after that I can drive as normal.<br /><br />The shop said the trouble was likely caused by my failing VRO fuel pump last year (which I've replaced with a standard fuel pump, and mix the fuel now myself).<br /><br />Now we just need some good weather here in MN (rainy spring)..