Excess oil usage after '07 Raptor rebuild

[Sun.flower]

My brother has owned a few 660s over the years, had an '05 and an '08 before, and now running an '06. he's never had any real oil consumption problems with any of them. But now he's helping me out, I just picked up a used '07 Raptor 660 that's giving us a bit of a headache. We rebuilt the top end right after getting it, new piston, rings, fresh cylinder work because it was burning blue like crazy when we got it. After the rebuild? No more smoke, runs strong… BUT it's still going through oil way faster than it should, there's no visible leaks, nothing on the floor, and again, no smoke. It just vanishes. We're checking it constantly because the level keeps dropping. It's baffling because his 660s never did this. Any of you run into something like this before? Could it be valve seals or something we overlooked during the rebuild?

 

[CharmlessMan]

My brother has owned a few 660s over the years, had an '05 and an '08 before, and now running an '06. he's never had any real oil consumption problems with any of them. But now he's helping me out, I just picked up a used '07 Raptor 660 that's giving us a bit of a headache. We rebuilt the top end right after getting it, new piston, rings, fresh cylinder work because it was burning blue like crazy when we got it. After the rebuild? No more smoke, runs strong… BUT it's still going through oil way faster than it should, there's no visible leaks, nothing on the floor, and again, no smoke. It just vanishes. We're checking it constantly because the level keeps dropping. It's baffling because his 660s never did this. Any of you run into something like this before? Could it be valve seals or something we overlooked during the rebuild?

you know, low compression can also be the reason for a motorbike burning oil. Try to check if the oil level is correct and that you're using the correct type and viscosity of oil for your Grizzly

 

[diplomaticdave]

If it's not leaking or smoking but still burning oil, it could be valve seals or guides, maybe missed during the rebuild, and yeah, check the crankcase breather; oil can get pulled into the intake and burn off without much smoke.

 

[Funny Cycle]

Aside from the valve seals, you may want to check the crankcase breather to make sure that it isn't clogged?

 

[common.person]

My brother has owned a few 660s over the years, had an '05 and an '08 before, and now running an '06. he's never had any real oil consumption problems with any of them. But now he's helping me out, I just picked up a used '07 Raptor 660 that's giving us a bit of a headache. We rebuilt the top end right after getting it, new piston, rings, fresh cylinder work because it was burning blue like crazy when we got it. After the rebuild? No more smoke, runs strong… BUT it's still going through oil way faster than it should, there's no visible leaks, nothing on the floor, and again, no smoke. It just vanishes. We're checking it constantly because the level keeps dropping. It's baffling because his 660s never did this. Any of you run into something like this before? Could it be valve seals or something we overlooked during the rebuild?

It could also be a head gasket issue right here. You're right about the valve seals, though. Keep an eye on the head gasket since the Raptor tend to surprise you like that.

 

[p@st@_frk]

My brother has owned a few 660s over the years, had an '05 and an '08 before, and now running an '06. he's never had any real oil consumption problems with any of them. But now he's helping me out, I just picked up a used '07 Raptor 660 that's giving us a bit of a headache. We rebuilt the top end right after getting it, new piston, rings, fresh cylinder work because it was burning blue like crazy when we got it. After the rebuild? No more smoke, runs strong… BUT it's still going through oil way faster than it should, there's no visible leaks, nothing on the floor, and again, no smoke. It just vanishes. We're checking it constantly because the level keeps dropping. It's baffling because his 660s never did this. Any of you run into something like this before? Could it be valve seals or something we overlooked during the rebuild?

Valve Seals are a PRIME suspect! Even with a top end rebuild, if the valve stem seals weren't replaced or seated perfectly, oil can definitely seep past them and burn off without visible blue smoke, especially if it's a slower, consistent burn. This fits the no smoke, just disappearing symptom.

 

[Sun.flower]

you know, low compression can also be the reason for a motorbike burning oil. Try to check if the oil level is correct and that you're using the correct type and viscosity of oil for your Grizzly

ohhh, yeah right. I actually haven't used the '07 in a while since the issue but I think we were using the right oil, we must have because that's what we've been using all the while
But anyway thanks, I'll cross check that and see if I can rule it out