1998 xcr 600 still burns coolant< replaced base gaskets head gaskets and water pump. coolant is in middle cylinder
can drain middle cylinder crankcase and coolant runs from hole. (overnight with pressure cap not removed to keep pressure in)
also compression test is good on all cylinders.performance is normal but lots of white smoke when cold?
any thoughts!!!

Pressure test the engines cooling system & watch for leaks.

Don

So you replaced ALL of the O-rings? Head o-rings, spark plug hole o-rings, head cover o-rings? Base gaskets tight and torqued??

Something must be pinched on the center jug.....probably a head ring? They are really dainty things and I wouldn't reuse old ones either.

What about water pump?? Any chance it is leaking into the motor??

pressure in engine now is from normal engine running. after engine reaches operating temp smoke subsides.
some one mentioned cracked head ,but when I changed o rings, domes all looked fine.
is there there any other seals in the bottom end other than the water pump seals? im suspicious of something water pump related because its cyl #2

Pressure test when not running and cold.
No more seals.
Might be a base gasket or dirt trapped when the base gasket was installed, unlikely to be a cracked head.

Don

My guess would be a bad o-ring in center cylinder or loose head bolts. If it only leaks when cold, then expansion is likely occuring and sealing it when running. As Don says, I would test this by attaching a coolant system pressure tester when it's cold. Apply about 10 psi pressure, and look for leakage on gauge. If so, inspect for internal leakage into crankcase or cylinder. If not, then start engine and see if pressure goes down or up. I just did this on a 1005 Price-engined 94 Storm drag sled a week ago that was leaking coolant and blowing coolant out of bottle when running only. Gauge showed no leakage when cold, but went sky high when engine was started. It was bad/misformed o-rings on two cylinders. Casual inspection of the bad o-rings showed no obvious problems, but new ones solved it.

While getting ready to race at Schuss Mountain last weekend, my own HTG/Flannery 1100 XCR began steaming white smoke into the exhaust system as soon as I started it up. I checked coolant bottle and it was low. Removed spark plugs and found coolant on center plug. Found some head nuts slightly loose. Tightened them, checked cyl base nuts, added coolant, bled system well, replaced plugs and it ran all weekend with no more coolant loss.

Coincidently, some Flannery employees happened by and were admiring the sled after the first run. I never mentioned what happened, but during a lengthy discussion, one of them mentioned that you have to keep an eye on the cyl hd and base gaskets constantly on the big bore engines. Your's isn't a bigbore, but the same causes can ocur in all these type Polaris engines. I've seen inferior o-rings, wrong sizes, pinched during assembly, coolant in head bolt holes preventing full tightening, etc.

This is precisely what killed our 98' XCR 700 big bore. Failed base gasket on center cylinder because of loosened base bolts. This one gave no warning. Driving down the field when suddenly a shitload of steam and antifreeze everywhere. It hydro-locked busting the base of the cylinder that fits into the case right off and cracked one "ear" off the cylinder. It also bent the water manifold! Needless to say the cylinder was hooped.

Decided not to fix it and removed the big bore kit completely and back to stock it went. Thank God I didn't sell the stock cylinders, pistons and heads. At least we were able to get it back up and running.

My advice would be to check your base studs and gaskets for corners pushing out frequently! It will save you a huge amount of headache.

Yep. When the Ultra 680 came out in 96, and people were installing triple pipes, they would leak coolant due to loose base bolts/more cyl hp and hydrolock and lift the cyls right off their base by breaking the corners off. Polaris had a very expensive warranty situation on those engines when folks would quickly remove the pipes and take it in for repairs.

I did check the base bolts occassionally after the big bore kit was installed, but after a period of time, you just forget about it and assume everything is OK after running it for hundreds of miles. WRONG.

I guess there was nothing they could do to stop guys from putting the stockers back on and putting their jetting back to stock and pawning it as a flaw?