01-14-2013, 07:51 AM #1
- Join Date
- Jan 2013
yamaha xl1200 pv engine, how to remove carbs? what else to check with engine out?
Working on a ~2000 XL12000 PV engine. Was my girlfriends, hadn't been used in a couple years, but was barely used otherwise. I don't know much about these machines, first one I've ever looked at in depth, although have tons of experience with outboards (down to complete rebuilds) and some with sleds.
To make a long story short I've got all the bolts off all the carbs and they won't budge. Tried gentle tapping and prying against block but it's not helping. Looked like maybe the seat of the carbs isn't where I expect it to be (ie could be part of a larger manifold or even one piece all 3 carbs), but still I expect with the 6 bolts out something should come loose. What am I missing? Manual I'm working with says remove 6 bolts then carbs and that's a no-go. Is there a good repair manual (like a Clymer or something) for these things?
OK the long story: Originally back in summer I charged the battery and tried to start it. Turned over once then made a loud electrical noise like the starter was stuck, then solenoid stuck on and turned the engine over until I yanked the battery terminal off.. Then solenoid was all done, wouldn't turn on again.. I replaced wimpy yamaha solenoid with a big marine inboard style (happened to be what was available on a Sunday) and found starter was good for like 10 seconds of cranking then seems to require waaay too much amperage like it gets hot and jams (loud electrical noise from starter or solenoid is generated). You could go back and hour later and try it again, same pattern. Didn't make a difference with or without a 150 amp charger, just a louder noise.. I call it as a bad starter or something wrong internally with the engine making it very hard to turn over..
During process engine still wouldn't start, got it to fire but not run by putting some fuel in cylinders.. So typical clogged carbs I also suppose given fuel unstabilized and more or less not run for 2 years.. Alot of things coming off to get to starter at a minimum, so doing carbs at same time no big deal.
Looking down spark plug holes looks like backmost cylinder either made contact with a spark plug or something at one time and/or there's detonation based on a weld like mark on the top of the piston. It's not a hole, rather looks like excess material, like a blob of solder.
So plan is, figure out what the deal is with the starter and fix, get carbs off and rebuild those.. Verify reeds OK, pull head and inspect, probably check tolerance on piston travel (not in that order).. Also thinking may as well crack crankcase and provide a sanity inspection of crank & bearings. Engine turns nice and smooth with a pinkee finger so is not stuck that's for sure.. Once I know internal engine OK and starter good I will bench test compression. Does that make sense?
Anything I should add to the list? Last question coming up is engine mounts did alot of twisting when I removed bolts. Are they just chincy out of the box or should I replace?
01-14-2013, 12:29 PM #2
- Join Date
- Jan 2013
Update - figured out how to get the carbs off, were the 4 allen heads which allows the 3 carb assembly to be removed as one piece, then individual carbs come off from behind with another set of similar allen heads..
Removed reeds and found water in crankcase. Could be something that went wrong when removing exhaust, as water ducts were all full, but also could be root cause of why starter was having such a hard time.
Cracked crankcase open. Actually looks OK in there despite sitting for I don't know how long with water.. Trying to figure out how to remove crank now, or to be more specific, how I will put the pistons back into the cylinders if I slide it out as an assembly. I want to get a better look at surfaces where the bearings ride.
Still looking for any pointers on what else I should be doing, thinking if bearing surfaces look OK then will put crankcase back together and fill with mystery oil, else start hunting for a used crank assembly - hopefully not.
01-15-2013, 12:07 AM #3
- Join Date
- Jul 2009
You may as well just pull the engine out completely. And rebuild it outside the ski. Then put it back in as a whole shortblock asssembly.
Taking it apart and putting it back together in the ski is much harder.
I would also tend to believe that water in the crankcase would mean your crankshaft bearings are no good.
01-15-2013, 07:36 AM #4
01-26-2013, 10:20 AM #5
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