81 Maxim550 potential rebuild candidate

Ok boys and girls. I’d first off like to apologize if I missed during my search. But i wasn’t able to find anything that way.
In any case. I think my little 81 550 is going to be due for a rebuild. Measured compression and she’s a tad low(lol) at 80ish psi across the board and its crop dusting blue smoke a tad. For the life of me however i can’t seem to find an all inclusive rebuild kit. Is there such a beast? I can find a gasket set, but I’d also like to pick up piston rings, valve seals, crank and rod bearings(while I’m in there). She’s got 25k on her(if the Speedo is accurate). Should i also worry about the timing chain? Any way. Any suggestions or recommendations are greatly appreciated.

 

Is this bike running now? Are valves in spec, are carbs rebuilt & synced?
the fact you're getting the same measurement across the bank begs questions, are you certain of your gauges accuracy, was the throttle wide open, other plugs removed?
Again, does this bike run now?
What you listed will set you back more than this bike is worth, but at 25k there should be no need to rebuild crank & rod bearings unless it has sat in the weather for some time.
A total motor rebuild only makes sense if the bike is otherwise excellent condition, or you love tinkering and don't mind blowing money, both things I'm guilty of.

 

25k is low miles for that motor, do you know the history of the bike? Curious what happened. Is your gauge accurate and are you doing the test correctly? The cheapy ones vary greatly in accuracy.

@Simmy LOL, me too.

 

If you are looking for rings etc upper right corner of page xj4ever has most of the parts , if you do rebuild make sure you do starter clutch as well.

 

Wwweellll..... I mean I do save up in a "slush fund" for just such occasions . As for the gauge it is fairly accurate. Ive used it on multiple engines since, and before. As for the gauge cluster on the bike, I dont really know. Now To be completely honest, I did it while in a hurry over the summer before a ride. I honestly dont even remember if I had the throttle wide open. It was just a thought that popped into my head last minute before the ride and being the impulsive creature that I am I did the test.
To be completely honest, I havent checked valves yet, and am suspecting that most of my lost compression is because of them, but I am also seeing blue smoke in the exhaust which leads me to believe that I potentially have ring issues. As for the bike it's self. Shes a little frankenstenian, but mostly original. Started life as an average 550 maxim, that needed a battery a new carb rack.
With the above installed, I cruised it for about a week and decided to cafe it. Fast forward a few weeks, a ninja front end, a hand made tail, fiberglass seat pan, and a secca gas tank later, she was sitting in my garage, painted and ready for wiring. I decided to simplify the wiring, and it was at that point that a friend dumped 2 additional bikes on me for next to nothing. Between them, and my other bike the Max got pushed to the side for a few months, until my ex sister in law said that she wanted to buy it. At this point I began to redo the bike electrical back to stock. It was pretty much at this point that my divorce kicked off full swing, I got single, and began to....well, do what single guys do lol. The max once more kicked to the side....for about 8 years. So basically once I brought it back to life with a fresh(but used) wiring harness. I threw a jet kit in the carbs to help offset the extra air provided by the dual K&N pods, and open exhaust, and rode around here and there through out the past two summers. And thats basically the bike history as I know it.

One thing that has always stuck out on the bike however. It was always ill mannered when cold, and there was always a weird tap which somewhat sounded like wrist pin slap, but was way too high up in the head on #4 for it to be that. Once the engine was warmed up, all weird ticks and noises went away. The bike also refused to idle well when cold. But adjusting the pilot screws fixed that. As for the high RPM side of the carbs, I set the main carb needle slightly more on the rich side from what the jet kit recommended. The idea there was that id rather foul up a plug, then put a hole in a piston or worse. I think I might have actually got lucky on the first try(which in my experience is rare) because the plugs when inspected actually look really good.
Anyhow, ive rambled long enough.

 

I honestly have no friggin idea how I keep missing that! Thank you.

 

For as long a you've owned this bike and the mileage, I would definitely check them. Could be a simple fix for low compression.

LOL, I do this too. Was testing my KZ750 last year and completely forgot to open throttle. Spent a few days thinking I was going to have to tear motor down before I remembered.

These bikes should tick when warm, another indication that your valve shims might be out of spec.

 

I would check the valve clearances first before you tear into the head.
What color smoke are you seeing? I've seen quite a few piston and ring sets from 20k mile 550s and they rarely are in so bad of shape they'd be sucking up oil. I'd say your valves and carbs need a lot of fine touches.

 

A clappy engine is a happy engine at least on the xj

 

Well its a bluish smoke. But oddly its barely visible during the day. I mostly see it at night when im stopped and there are headlights behind me. I tend to agree with you on your points. Eh. Maybe ill just settle for valve clearances and such. The carbs definitely need to be gone over again too. Im pretty sure of this, and every bit of "OCD me" is kicking my ass for not doing that before going last summer. Just hope I didnt smoke the valves completely if I do find them on the tight side.

 

Ha! ill keep that in mind.

 

Blue smoke is from unburnt fuel. White smoke is oil. They also smell totally different but hard to explain. Check the valve clearances first.