Stuck rings??

[Hillsy]

Hey fellas,

I got hold of an old FJ1100 for no much $$$ and started working on it yesterday arvo. It was running, but pretty rough (wouldn't idle) so I cleaned the carbs, tweaked the float valves / height corrected, slides loosened up, all good.

It fired up pretty much straight away, but after a few minutes it started smoking. I then changed the oil (it smelt a little bit of fuel, but wasn't too bad or overfull) and fired it up again, but the same thing - nothing at the start but then it started smoking when it warmed up.

It was getting late in the afternoon by this time and I had to shut it down and come back to it some other day. Plus the smoke signals where attracting the neighbours attention a bit too much.....

Is it possible the rings have just gummed up from sitting? If so, is there a method / technique / additive that will free them up without pulling the top end off?

I'm thinking I'm probably screwed here, but if any of you guys have something to try, I'd appreciate the advice.

Cheers.

[Dynomutt]

You could try dropping a load of plus gas down the bores and leaving it for a day or two, drain all the oil out afterwards and refill with a new filter. However before doing that I'd do a compression test, first do the test dry and record the results, then drop a few Ml of oil down the bores and repeat the test and compare the results. IF the rings are gummed up the wet test should give a higher result than the dry by quite some margin, as the oil will temporarily seal the bores. If the test results are within 20psi of the dry test then it's likely to be the valves.
If it does appear to be the rings, then try soaking with plus gas, keep toppping it up over a couple of days, if it doesn't free them up then you'll need to pull the top off the motor, then give it a quick hone and re-ring it.

[Hillsy]

Cheers - I'll do a compression test during the week and see what that reveals.

By the way, what's plus gas?? I haven't heard that term over here.

[ALBI]

95 or 98 fuel

[Hillsy]

OK - did a quick compression test (with the engine cold but wide open throttle). Got 120, 90, 90 and 120 across the four, then a teaspoon of oil in each pot and they all came up to 120. So, it looks like the valves are OK, but cyls 2 and 3 are in need of attention.

I might try the gas trick and see if it gets any better.

Cheers Dynomutt :cool:

[Dynomutt]

Plusgas is a release agent, like a penetrating fluid, I do not know if you can get it where you are or not, but I would assume other proprietry products are available that do the same thing. Yes from the results of your comp tests it looks like the rings/bores are the isue rather than valves. If soaking the rings does not work then the only option is a top end strip down, in which case you may as well fit new rings, and clean up all the valves and fit new stem seals whilst the top end is apart.