Is time that relative and or i think i got lucky

[AirJunky]

Some of you guys mention proper maintenance. What's to do on these things? I've been using descent oil. Checked the plugs a couple times. It runs great so I don't mess with it. I did add a primer early on. And all year it's started super easy. Even in the winter when water temps were in the 40s. There no oil or ignition parts to replace. Maybe plugs eventually?

[john zigler]

Some of you guys mention proper maintenance. What's to do on these things? I've been using descent oil. Checked the plugs a couple times. It runs great so I don't mess with it. I did add a primer early on. And all year it's started super easy. Even in the winter when water temps were in the 40s. There no oil or ignition parts to replace. Maybe plugs eventually?

Every machine is a little different...

Basically, go over every nut, bolt, and hose clamp make sure they are tight.
Clean/replace fuel filter-water separator.
spark plugs.
Depending on plug caps, remove, and cut wires back. (NGK screw on type)
Grease all cables, driveline, Steering post, steer nozzle bushings etc.
Check impeller for wear
Check all hoses, cooling, exhaust, fuel, oil, for wear cracks etc.
Run pure gas, non-ethanol.

If you have not so recently, go through your fuel system completely. Rebuild carbs, replace all lines, fuel select, etc.

And so on....

[THE OLD MAN]

All of the posts on this thread have been a great help and I'm glad I started going threw every thing on the ski. If not I would have had a big surprise. I really want to ride in the worst way. ( having only been on a ski once). But finding the ball stud on the steering cable only 2 turns from falling out, I'm glad I took your advice. So she is down till I can trust her.
I cleaned her up inside and out today. It was pretty clean inside, I take that as a good sign.
I did find 3 cracks in the top of the hull one in the front, one on the side and one on the right rear, all above the gun wail except the rear one, it is right on the gun wail. Time for some fiberglass and gelcoat.
Time to order some stuff. Cables, carb kits, needle and seats, fuel lines and filters. extra plugs. I will be doing the carb mods and "T" handles, just sounds like a good idea. Still need to do a compression test when I can remember to bring my gauges home.......

[driftmaster]

Do not replace the original fuel lines. Yamaha line very rarely ever goes bad. Protec Yamaha no longer stocks Yamaha line but they have Honda line in stock, next best thing.

[THE OLD MAN]

Well, I finally brought my compression gauge home. Cold compression on all 3 holes is 115psi.....well at least they are even. I guess its ok for a 20 year old. At least it looks good now, buffed it out and streatched out the gunwale trim so it fits now. Any preference on pistons? I used wiseco back in the day, but the rings are so thin, that it was an every other race thing. Anyone know if they carry a thicker ring piston? this will be the first 2 stroke I have touched in 30 years.

[driftmaster]

Being all three are at 115 I'm not trusting your compression gauge. If you just like working on things, your welcome to come over to my shop.

Pro-x is decent piston.

[THE OLD MAN]

Driftmaster, that is a valid point. It looked to even to me compared to what I have read. Ill get another gauge and test again. I would love to work at your shop, but the commute would be a killer.

[JSNate]

I have personally seen 2-strokes with over 500 hours, still running, original, and have seen some with less than 100 hours with major issues....

It all depends on how they have been taken care of and maintained.

What I have found in 30+ years of service here, People tend to not do preventative maintenance, and just ride until something breaks. They leave them full of water, tied to the pier or on the beach, never grease anything, run the cheapest gas, cheapest oil, etc.....

I have had customers who regularly get tune ups, and meticulously maintain there machines, and NEVER have any issues. Others who their machines nickel and dime them to death... ( Usually because they don't take care of them, they just ride the **** out of them, WOT and put them away wet.)

The condition of the engine compartment will tell a story.

Yep!

[THE OLD MAN]

Well, mistery solved. Driftmaster you were right my compression gauge is off. Second gauge says 120 +-3 psi on all cylinders. I took a bore scope and looked in the cylinders and the pistons are all.050. The cylinders all look clean. The pistons are flat top. Don't know what brand. On a car engine I expect 145-155 comp average. What is optmal for the 2 stroke?. The guy I got it from has no clue. I did note the engine compartment and the inside of the hull bottom is quite clean.

[driftmaster]

Looks and sounds like you have a new engine. Stock Yamaha pistons don't have much of a crown, so their probably not flat tops. 120 is stock and a good safe number for the 65u, 145 is the max Unless your smarter with engines then most here.