XH Motorcycles Forum
Motorcycle Resource Forums => Technical Resource Discussion => Topic started by: franknsr on September 27, 2025, 04:41:13 PM
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On Saturdays ride in the Dells, someone told my wife that my bike was smoking like a Rastafarian. The bike runs great but has a history of oil consumption, so here we go.
Finally had a chance to look into this a little deeper and I have some data, but don't trust the guy who took the reading, so I'm looking for a second opinion.
Pulled the plugs and both looked black, so they were definitely burning some oil, and its not the good midnight stuff.
Did a compression test, engine cold, throttle wide open, front cyl was 115 psi, rear was 113.
Put a couple ounces of oil in each cylinder and the front went to 162psi and the rear went to 232.
Spec for the bike is 185 to 205.
Based on that I think both cylinders need to be serviced, and there is possibly and issue with the front head/valves. About 100 years ago in auto shop, Mr Ward told I could check the sealing quality of valves by removing the head and turning it upside down on the bench and fill the head with gas and see if it leaks out. Is that still an acceptable practice?
After all that rambling I'll just add that I'm not afraid to attempt anything but have only rebuild a few engines in my time so I'd appreciate any input.
Thanks
Frank
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That definitely sucks that it's doing that. I can't remember if you've had one of these engines out yet. Don't even bother trying to do this in the frame.
To get the engine out, the trick is to remove the starter motor. Wrap the frame up with split foam pipe insulation and zip ties. That makes it easy to lift and rest on the frame without damaging anything.
On to the repairs: I know nothing and I'm just sharing how I would approach it. - From my experience with pulling one top end, I would not count on the getting it back together without doing Time-Serts on all eight cylinder fasteners. Mine pulled the threads with almost no torque at all. That necessitated pulling the engine out of the frame to get it up on a mill for proper insert prep and installation.
- I would also count on buying the ARP stud kit from Seastrom. Because they're studs, there's no access to do this in the frame anyway.
- For the cylinders: I don't see any oversize pistons in the parts list. Renewing those cylinders might be a challenge. Are they nikasil? I don't remember. If so, they can be replated to stock bore size. Seastrom should have piston kits. If they're iron liners, he may even have other solutions like aftermarket pistons or maybe there were some factory oversize pistons that never made the parts list?
- Same for the heads. Guides and valves have been regularly available on eBay and I'm sure he'll have inventory too. Yes, I've filled ports with water to see if it leaked out of the valve periphery. You know the drill with the guides: pull the retainers and springs and see if the valves are sloppy. I'd find it hard to believe a set of valves and guides wore out but, we don't always know how these bikes were treated.
What are you thinking of doing with it? You could just keep it as-is and ride it. Not the end of the world. The bike is 26 years old.
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Yeh ...I have learned in the past about assembly on the top end of engines in the factory...employees were not taught about the
offset of the rings on pistons in the beginning...they were actually lining the gaps on the rings in line with them all ....Jamie and I discussed this
before... so some bikes were let go in assembly and shipped out
before they caught the problem!!!! hence the burning of oil just an FYI
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I remember back in the day conversation about this, and honestly couldn' believe it.... until I had tpo replace rear head gasket. And there it was.all the rings lined up.
I never smoked. And I've never fixed the front one. I'm pretty sure though it has to do with mine running fairlys rough.
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Thanks for the info and the conversation all. I have Deadwood I'm resurrecting so I'll have something to ride next season, so I'm kinda looking forward to pulling this one apart and breathing new life into it. Not sure what went wrong to require this kind of work after 40k, I honestly expect most of these motors could go much further with normal care. Mike has always done a great job of supporting us with info and parts so no worries there, but I do enjoy the occasional trip to flea bay for some bargain hunting. I do have a "parts bike" and was going to 'Jumper' this thing back on the road by throwing a new motor in it, but the purist in me won't allow that.
Was really looking for a quick gut check before tearing into this and I think the consensus is that it needs to be done, so thanks for that.
As DH says, Onward and Upward.
Frank
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40K miles? Man, you need more bikes so you can spread the miles around. I try to keep them running often enough that I don't have to tear into the fuel pump or replace the battery the next time I get to one. :)
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Is a compression ring supposed to be in 4 pieces? Asking for a friend.
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your humor makes me giggle buddy
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How does the cylinder wall look? Ouch.
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Originally it looks scored, but it cleaned up nice with a hone and surprisingly measure out just fine. Just picket up the part last weekend so I'll be slapping her back together next weekend. Going to be 42 F here on Saturday so maybe a test ride is in my future!