vmax 600 top end rebuild question

L

Lobeydome

New member
Joined
Feb 6, 2011
Messages
7
Age
54
Location
United States
Bought a 96 Vmax XT last year with 1500miles (supposedly). Big mistake. It ran pretty well but got poor gas mileage (40 miles on a tank). Doggy out of the corners and top speed about 75mph. I did as much as I could to figure out problem and finally took it in. Had poor compression (I know, should've checked before buying), both cylinders were badly gouged on the exhaust side. After seeing it, I'm surprised it ran as well as it did. I think it was burned up lean at some point and perhaps new pistons and rings put in but left jugs alone and then sold to some sucker (that would be me). So I don't want to stick a lot of money into this. Found someone local that has jugs off a 94 that have "light scratches". What is acceptable scratches. My current one's were pretty gnarly looking and the engine still ran. Can I reuse the pistons I have if there is no visible damage? I would get new rings. Are gaskets reusable? If I can put it together for a couple hundred bucks and it holds together for a few seasons, I'll at least feel like I got my moneys worth out if it. If it blows after that, Ill have parts for sale

Thanks
Lobeydome
 
You can remove the aluminum that was deposited in the jugs with acid (not sure what kind) and they can be reused if they are in spec. Don't want to take any of the coating off the liners by putting a hone down them or anything.
 
It would be best if you could post pictures of the cylinders you want to use along with the pistons. The light scratches could be aluminum deposits from the previous set of pistons. Hard to tell without seeing the cylinder bores. As long as teh pistons measure out to be within the service limit dimensions and they are not damaged they should be fine. You can get repaired/replated cylinders from US Chrome or Millenium for about $200 each, expensive I know but they are as good as OEM new.

Jim
 
rx1jim said:
You can get repaired/replated cylinders from US Chrome or Millenium for about $200 each, expensive I know but they are as good as OEM new.

Jim
Click to expand...
This would be my recomendation if you are going to keep the sled for a few years like you said.

Meratic acid to take aluminum off cylinders.
 
No, gaskets cannot be reused unless you want to keep chasing engine problems. DO NOT use any acid to clean the cylinders, any acid that will remove deposited aluminum from the surface of the nicasil coating will etch the cylinder in places where there maybe pinholes in the nicasil coating. The nicasil coating is plated directly on the aluminum cylinder. Use a scotchbrite pad to remove aluminum and carbon deposits. The scotchbrite pad will do nothing to the nicasil, it is extremely hard.

The amount of rebuild work you do is a matter of what you are looking to do with the sled. You could get by with a minimum amount of work and new/rebuilt parts if you only put a few miles per year on the sled. Most of my riding is long distance saddlebag trips through some pretty remote country so I go over-board during the rebuild process.

Jim
 
Great advice here, thank you. Most of riding is local and usually less than 150 miles per trip. I plan to buy used cylinders that have intact plating, reuse pistons with new rings and new gaskets. Sounds like this should get me going and keep me going for a couple seasons. I go tomorrow to pick up used jugs. To all who take time to respond in these forums: Thank you. You really are a great resource.
Lobeydome
 
Don't discard the original cylinders that are damaged. You can used them as cores if you decide to exchange them with a cylinder remanufacturer in the future.
 
Don't just put it together and run it without checking things out. Otherwise you may be rebuilding it again. Whatever caused the damage in the first place may still be there. Did it run lean? Run hot? Lose lubrication?
 
i think the rings caught the exhaust port and last owner just put new rings in without replacing the damaged cylinders. Was enough to get it running and sell. It does have gyt dual pipes but jetting appears to be set up as recommended by Yamaha
 
You must log in or register to reply here.


Back
Top