XT600E Smoking/Low Compression/Oil Consumption.
 

I'd like to get some troubleshooting advice on my 99 XT600E, last fall it started smoking like crazy on
start up, white smoke, started up about the same as usual which is to say not immediately but
always reliably, except of course in spring when it takes a bit more coaxing, power seems to be the
same as when I bought it 3 years ago, it's got 60.000 + km on the odo. at about the same time as the
smoking appeared it started using oil like gasoline, would use a whole litre in 2 to 3 hours. I've done
a compression check it's got 55lbs :-(
So I'm wondering, is it time for a top end or could the lack of compression be caused by tight
valves ? can that also lead to oil consumption ?
I could also use some help with general specs, since my bike is a 99 and XT600's were not
imported to north america after 95 I don't have access to the usual manuals. I'm looking for valve
adjustment procedure and specs, top end torque values, stuff not to forget relating to gaskets/O
rings/seals etc, and any tips or advice would be greatly appreciated.
Thanks guys.

Rings ?
 

The valves are work checking for sure but it sounds like worn piston rings to me.

Hi ,just read the specs for the compression and your is way too low.It should be about 156 psi at sea level so yours is way down.You can pour a little oil into the cylinder and recheck the pressure.If it gets better its your rings.

You should be able to download a service manual from the net somewhere. I,m sure someone will post you a link soon.

XT600 service manual
 

Try these! :)

http://www.horizonsunlimited.com/hub...download-32180

Dan

Valves don't burn oil THAT fast... It certainly looks like ring/cylinder..

Of course, check the bike for leaks elsewhere too and especially the head gasket. It should be pretty obvious if you're losing that much.

Time to get that engine out, open your manual and get the kettle on !!

It's not that big of a job. Rings should cost about £25, gaskets £25..

Have the bore measured up to see if you need oversize rings. If not, get it honed anyway. XT's don't have a nikisil bore as far as I remember.

Btw, tight valves woudn't cause you to burn oil although these should be check as a matter of routine anyway. Also an easy job on the XT.

Thanks everyone, I've tried those pdf files a few times but it keeps freezing my computer, I do have an online pdf manual for an 03 or 04 TT600RE I hope it's good for my 99 XT. it turns out the intake valves were tight so I adjusted those and the exhaust valves to the specs from the TT manual, 0.05 ~ 0.10 mm intake and 0.12 ~ 0.17 mm exhaust. I've gained a bunch of compression but not enough to get the bike running. I was hoping for one more season out of the beast but I guess it's time to pull it apart and dig out the micrometers.
http://i879.photobucket.com/albums/a...18b676x507.jpg
http://i879.photobucket.com/albums/a...22b676x507.jpg
http://i879.photobucket.com/albums/a...26b676x507.jpg

With the amount of oil you are loosing I am not surprised that adding some didn't do much to the compression.

Whip that cylinder off, it won't take long :smartass:

I've pulled the top end and thought I would let everyone take a look, is it just me or should these parts look much worse than this considering the excessive smoke/oil consumption and the low compression ? I know the tight intake valves were part of the cause for low compression, but I was expecting to see something much worse than this, or will I find the answers when I start taking measurments ? any suggestions ?
http://i879.photobucket.com/albums/a...440512x384.jpg
http://i879.photobucket.com/albums/a...459512x384.jpg
One of the exhaust ports.
http://i879.photobucket.com/albums/a...5512x384-1.jpg
http://i879.photobucket.com/albums/a...507512x384.jpg
http://i879.photobucket.com/albums/a...500512x384.jpg
http://i879.photobucket.com/albums/a...533512x384.jpg
http://i879.photobucket.com/albums/a...524512x384.jpg

sidequestions: where does the valvesealings sit? around the "valvepin"?

do you wash/flush the engin internal before dissembling? it looks so clean...

maybe dumb questions... but im asking anyways :)

You think that doesn't look bad ?? lol

Anyway, you can see with all the carbon build up on the valves, plug and piston that it was burning oil.. Lots of buildup.

Now you're this far, measure the bore and check it's within spec. You might need to go for oversize rings if it's excessively worn. Also check the valves are seating properly after all that buildup and burning. You may need to lap them in again...

You now need to clean the piston, replace the rings, have the bore honed, change your valve seals and put it back together with a new gasket (after cleaning down the mating surfaces)

New plug and make sure your valve clearances are spot on....

:scooter:

Thanks TT, I know the carbon buildup is bad but I guess I was expecting to see broken rings or a chunk missing from one of the valves, this thing was using a litre of oil in a two to three hour ride ! I took some close up detail shots of the rockerarm/cam followers, they look good to an untrained eye. The rings were gummed up pretty bad, the 2nd ring had no movement at all but was fairly easy to remove, I fit the piston back into the cylinder and it seemed a bit loose, I'll have to buy a 4" micrometer to get more accurate measurments, as you can see in the photos the piston has lots of holes for the oil to get through, not sure if the Wiseco has more or less than the oem Yamaha part. checked the side clearance of the conrod big end/crank, slipped a 0.59mm in there but couldn't get an 0.61mm to go, the specs show 0.35 ~ 0.65mm. the specs I have are from a pdf file for a 2004 TT600RE manual, I still gotta check if this thing has a nikasil cylinder cause the manual is saying to replace the cylinder liner if it's out of tolerance. oh yeah and there's no ridge at all at the top of the cylinder :-)
http://i879.photobucket.com/albums/a...543512x384.jpg
http://i879.photobucket.com/albums/a...548512x384.jpg
http://i879.photobucket.com/albums/a...550512x384.jpg
http://i879.photobucket.com/albums/a...551512x384.jpg
http://i879.photobucket.com/albums/a...565512x384.jpg
http://i879.photobucket.com/albums/a...566512x384.jpg

Not a dumb question bikereurope, if I understand your question, by "valvesealings" and "valvepin" your meaning as far as oil is concerned, the valve stem seals are on the opposite side in the photo I posted of the combustion chamber, the rubber seals sit inside the valve springs and prevent oil from being drawn into the cylinder when the valve opens, whenever you see an engine "puffing blue" it's usually because the soft rubber valve seals have hardened and cracked allowing lots of oil into the the cylinder and out the exhaust.

No I didn't flush the engine, but before I removed the cylinder I used a vacuum cleaner as I scraped some of the crud off the piston top just to keep crap from getting in the cases, I just wiped the cylinder with a rag for taking the photo.

It might be a god idea to change the valve stem seals while youre in there, they are very cheap.

I wouldnt think the cylinderbore and piston would be within spec when you're burning so much oil, but you might be lucky.

I'm almost certain is doesn't have the nikisil bore..... Although please check on this !!

You don't have to use a grinding hone if it's not but you should use a rubber ball hone to remove any glaze or build up..

http://www.bayarearidersforum.com/fo...7-dsc01221.jpg

The Xt's have a iron plate, no fancy nikasil for us :nono: :smartass: