Interference engine?

[ksquier]

Does anyone know if the 2001 GZ250 has an interference engine or not?

[Sarris]

Huh?? Do you mean interchangeable? as far as I know, any GeeZer engine should fit in any GZ frame.

Post again if that's not what you mean.

:??:

[ksquier]

No, I mean interference. An interference engine is an engine where the piston can hit the valves if the timing chain breaks. If the timing chain were to break, would the piston hit the valves? I'm a mechanic and I'm looking to buy a GZ250 from someone that has engine problems, possibly a broken timing chain. I don't want to fool with it if it has an interference engine.

[Easy Rider]

Originally Posted by ksquier

I don't want to fool with it if it has an interference engine.

I don't know for sure but I suspect that it is.

We had some pictures posted in the past week or so of the piston and heads, slightly damaged by a dropped valve.

You can draw your own conclusion from the pictures if you can't find any other information.

My first thought was that the GZ's cam is gear driven.....but that doesn't make sense so it's probably wrong. There is a shop manual available here for download.

[blaine]

Yes,if the timing chain broke the piston would hit the valves.The clearances are very close. :2tup: :cool:

[ksquier]

I was hoping that was not the case. I may not fool with it then. The guy lives about two hours from me, so I haven't had a chance to go look at it. He doesn't know anything about engines. He says that while he was riding at about 35 mph, the engine revved up, made a loud pop, then some ticking, and then died completely. He says it turns, but no longer starts. The first thing that came to my mind was the cam chain breaking. I'm not familiar with the GZ250, so I don't know what kind of common problems it has. The bike has about 20,000 miles. What common engine problems do they tend have, if any?

[Water Warrior 2]

Why did it rev up ?

[Easy Rider]

Originally Posted by ksquier

What common engine problems do they tend have, if any?

Based on the reports we have here.......none, if they are properly cared for and not ridden near their upper design limit.
Keeping the carb clean is about the only "common" problem that I remember.

[ksquier]

Originally Posted by Water Warrior

Why did it rev up ?

The owner says he doesn't know. All he knows is what his brother told him. It died while his 310 lb brother was riding it. Besides the fact that a 310 lb person probably shouldn't ride such a small bike, something tells me that his brother might have done something stupid.

[Water Warrior 2]

Originally Posted by ksquier

The owner says he doesn't know. All he knows is what his brother told him. It died while his 310 lb brother was riding it. Besides the fact that a 310 lb person probably shouldn't ride such a small bike, something tells me that his brother might have done something stupid.

The GZ will carry that much weight but not while an idiot is at the controls and doing sinful things to the bike.