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head teardown and new valve seals

Started by silas, April 30, 2012, 03:12:41 PM

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JMR


fj1289

I agree - I'd give it a chance to seat the rings first.  Take it for several rides and make sure you put a good load on the engine - don't baby it (no need to abuse it, but some good hard acceleration up through the gears, let it cruise for a while and up through the gearbox again - up a bit of a hill if you can). 

I'd use the bon-ami / baking soda trick as a last resort once you've tried everything other than tearing down the engine. 

Good luck!
Chris 

silas

Back again! Since my last post, I've torn everything down to the crankcase, replaced the rings, honed the cylinders with a Flex-Hone brush, and lapped the valves. I see now that I should have done all of this the first time. Just part of a proper rebuild. Still learning.

If anyone needs to hone their bores, I'll be posting this Flex-Hone brush in the tools section. It's 83mm 240 grit silicon carbide, so it ought to be wide enough to work on big-bores as well as stock. Great tool and made right here in LA. I bought it direct from the good folks at Brush Research headquarters. http://www.brushresearch.com/brushes.php?c1=2

Everything's back together now too. Been a while since she's had her plastics on. Had a warm up session yesterday to balance the carbs and set the mixture screws. All sounds normal. It burned off quite a bit of smoke, but I believe most of it was leftover oil in the exhaust collector box.

A lot less smoke today. Took it for a 3 mile run around the neighborhood over some decent hills. Feels like (and smells like) I need to tune the carbs a bit more, but overall the engine pulls nicely. Didn't ride long enough to make sense of the myriad engine noises, but plan to take her back out in a bit now that the day is cooling off. Fearing some piston slap on #4. Will the noises diminish as the rings set?

I decided to go with Rotella HD 15w-40 for the break-in. Various reading in addition to advice from my old man led me to it. Plus it's cheap and conveniently packaged in a 1 gallon jug. Shifting was a bit clunky today, but smoothed out in the third mile as she warmed up.

Question: When should I do the first oil change? I've installed Randy's spin-on adapter and found the WIX 51334 filter at O'Reilly's for $7. Works great!

silas

I've put 235 miles on this past week, and it's reminding me why I wanted an FJ. So. Much. Effing. Fun.

Rejetted with fresh 110 mains and upgraded to 42.5 pilot (from stock 37.5) last night. Throttle response and idle are perfect. It seriously takes off mid-throttle, and I'm officially afraid of opening it up all the way. So. Much. Effing. Power. If you're rebuilding your carbs, don't even waste time or $15 with the 37.5 pilots. I had far too much trouble dialing in and blipping until I put the 42.5's in.

The rings have seated quite well. No smoke, not even on startup. No more funny engine noises except the common ticking from the top-end. Plugs all look good.

Shifting is a bit clunky with every other gear change, particularly in 1st and 2nd. The clunk is lessened if I slip it into gear with the RPM/MPH in the right ranges. Drained and cleaned the clutch, which helped a bit. No slippage at all though. Pulls solid and strong in all the gears.

The Rotella 15w-40 seems to be ok. Oil level has been holding steady since around mile 50.

Time to rebuild the forks. Left side seal is a little bit weepy, but handling is just fine. Just a little stiff.

Stay tuned for more adventures in FJ rebuilding...