TOPIC:

Ok so it was 40 this weekend (WI) and I couldn't make it to the garage which just about killed me. So today we get 6" of snow and I'm in the garage. . Pulled the carbs...not the worst shape. Noticed cylinder 1 and 2 choke flaps are gone. Cylinder 3 and 4 are there!! These are the first original choke flaps I've ever seen in person! Can't believe more ppl don't have issues w the motor eating them. Anyway, I drained the oil, replaced w rotella T and did a compression test. The bike has 6k on it. I think the guy said he rode it in 2006 and 2007. Sat since, and hasn't been ran at all for 2 years for sure. So with a 25 deg motor and no valve adjustment I got...
Cyl 1 135
Cyl 2 135
Cyl 4 120!
Cyl 3 123ish.
That got me thinking... Why would 2 be lower. Maybe valve adjustment. Maybe I sprayed more kroil into 1 and 2 than 3 and 4 (3&4 were against the garage wall and space was limited).

So I went back to #1 again which was 135 the first time. Got like 126 the 2nd time. So maybe the battery was dying a bit. Or maybe I got a little oil in my gauge.

Anyway was hoping to see a little more consistency and higher values...

I would think a choke flap getting into a motor would pretty much destroy that cylinder/valve etc?

I agree, but my original 550 had no flaps no issues. I haven't seen anyone on here say they had damage due to it. Come to think of it I only have seem one person post they actually found a flap in the chamber. I think he removed it and life went on.

Another odd thing...the tank looks the same as my 550 and the frame where it mounts looks the same, but the little peg thingy that clips into the rubber mounting bracket at the seat side of the tank isn't on this tank...even though the place for it to buckle in is on the frame. Doesn't look like the tank has been modified, so the tank must be from a different model...

Also notice the PO moved the petcock to the fuel sensor hole and blanked off the original petcock hole....hmmm...

Ah ha! I knew that the tank off a 750 (used to have one) was the same more or less than the 550...but my dad had a 1980 440 LTD and the tank was about the same size - sure enough, I looked at the part diagram and it's a 440 tank I think. It has that prong with the big hole in it and the diagram shows a bolt attaching it to the frame... Sometimes trying to re-create the previous life of these bikes can make a guy feel like Sherlock holmes...

Does anyone have any comments about the compression numbers? Manual says 130-160 when hot, no more than 15 psi difference between them. So...mine should be ok, right?

Change the oil and filter first. No telling how long and what's in it over the years. Watch what comes out first, as it could be old fuel, or water. I wouldn't want that mixed up again in my engine. Once running, drop the oil pan, and clean out the sludge that you know has to be in there from condensation from all of these years.

Low mileage is good, but you gotta remember old seals/o-rings will start to seep when the engine warms up. Keep an eye out for these.

Make sure you have clean brake fluid and good working brakes, before taking it out on a ride down the street. Most accidents happen on the first ride if this is not checked. be careful, and wear a helmet, and protective gear as well.

Spark plugs are old and so are the wires. If the spark plug wires are stiff, then replace them.

+1 on doing a valve adjustment check. A tight valve can cause a lot of running issues.

Carb rebuild is also recommended.

Drain and clean out the gas tank. Water sits at the bottom, and can rust out a tank over time.

Have fun with this.

CoreyClough wrote:
Make sure you have clean brake fluid and good working brakes, before taking it out on a ride down the street.

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Yes, change that brake fluid, I do it like oil changes annually and rarely get any problems with sticking brakes, even on bikes in long term storage. Get some penetrating oil like 'plus gas' aerosol or similar, and soak a day or two beforehand, and a quality ring spanner or socket on the nipple. Nice to see the cloudy old crap bleeding out replaced by decent new fluid.

Old 'barn find 'bikes are like new rebuilt bikes, the first few miles are 'shakedown' and work through the problems before you rag it.

550's are the ace in the flush -the best of the 8 valve air cooled fours imo.

I threw my carbs from my good bike on and it fired right up. running on 3 cylinders. then i started to hear a slapping horrific noise - then saw a puff of smoke from the header by #2. immediately i thought oh no whats wrong. then i realized it was just a really really poor job of mating the header to the head and it was about as bad of an exhuast leak as you can imagine. if you stuck your head down there, the breeze from it could have ruffled your hair. Quickly ran it through the gears on the center stand and then shut her down. I sure hope that the bike was not ran like this for long by the PO. I'd almost HAVE to think it wasn't that bad, otherwise he'd have hardly no power and the noise is bad enough sounding for anyone to know something is not right.

Now... tomorrow... pull all the accessories off and MAYBE pull the motor. I was pretty happy though about tonight - old plugs...old coils...stone cold dead for the past few years... it popped right off.

ok guys...last night I was able to start the bike up. Tonight I decided before I get any further with pulling the motor I'd take a peek at the valve clearances. Like some stated, w the low mileage it may not need it. wrong. Almost all the valves were out of tolerance, but at least they all had some gap... but there was 2 of them that had 0.06mm gap and the tolerance lower spec is 0.1mm. jeesh...glad I looked.

Anyway, now I gotta do some math and figure out which shims I need and try to find a place where I can just buy 1 shim and not a pack of 5...or better yet, a shop that will trade me with just a few dollar fee.

I did find some damage though... not sure what in the world caused this... but you can see on the journal in the head, the edge of the aluminum is cracked a bit. Not sign of any damage on the surface the cam rides on or on the cam, nor any aluminum kibbles laying around. Does this look like maybe someone didn't install a cam right and torqued it down or maybe was really rough taking it out? SInce its not on the surface much I'm hoping I can just smooth the rough edges out with some emery cloth and call it good.

Also found an external crack... That appears to be someone used too long of a cam cover bolt... Hopefully just some jb weld or the like, some sanding and no harm no foul...

nice corroded pickup coil too... good thing I don't need it.

Was able to get the pipes, carbs, coils, side covers and airbox off in preparation to pull the motor.

Can't say what caused it. But make sure to put the caps on in the right direction so the thrust surfaces are in the right place.

Make sure to clean out the bolt holes. Get all of the oil and sealant out of the holes before installing the valve cover. Not doing so is what causes threads to strip and maybe even that crack. If it's not leaking, I wouldn't worry about it until it does,