How many Hours before a rebuild?

I am rebuilding the top and bottom end of my boy's IT200. All new bearings, rod pin, rod bearing , con rod, piston with fresh bore job etc. I am going to install a hour meter on his bike when finished so how many hours before a top end rebuild is needed and a another bottom end rebuild is needed?? I know there is a lot of variables so I am looking for just a rough estimate. Any one have a good idea?? I am using Yamaha Lube R at 32 to 1 premix. Thanks guys.

I'd say 200-300 hours is a rough estimate for a top and I've never had to rebuild my bottom so when that goes I'll tell ya ;). A lot of the top end depends if he races if he races I would say once a year

I'd say 200-300 hours is a rough estimate for a top and I've never had to rebuild my bottom so when that goes I'll tell ya ;). A lot of the top end depends if he races if he races I would say once a year

 

No on the racing yet but he is talking about harescrambles and enduro's. I know the top ends are easy to check and fix. I was kinda of curious if any one had a idea on how often I should check it. Thanks

throw out the yamalube.

 

i would suggest amsoil interceptor it burns very clean, its not a wide open mx bike so a clean oil would be a good idea.

throw out the yamalube.

 

i would suggest amsoil interceptor it burns very clean, its not a wide open mx bike so a clean oil would be a good idea.

 

 Well I will switch oils when these 5 gallons I have are used up. My brother use to work at a Yamaha Dealer and got my a great deal on a couple of case's of gallons a few years back. I am not throwing it out!! lol When I switch I will switch probable to Klotz. I have used amsoil in a snowmobile and with in 500 miles the rod seized to the crank and broke. I am not saying it would have not seized anyways as who knows if it was starting to go before hand?? I bought another new sled and put 9200 miles on it using Klotz and all I ever did was change one set of pistons up to date. I am sure its time for a rebuild but that engine averages 6000Rpms for 9200 miles is a lot of revolutions! To me that says some thing about the oil and it Smells good as well. LOL

Edited by Zrt1200

klotz is a great oil as well.  The sled problem was not the oil, I ran dominator @ 30;1 in my summit 800, 880 mod big bore, big bore carbs, oil injection delete etc, It was a steep and deep sled, climbs as long as 5-7 minutes locked to the bar wide open. 3000km on the big bore when i sold it (I'm amazed the crank lasted, they are crap on the 800r)

Edited by adam8781

Ok, tapped the old and grey wise one who is the IT guru (former IT racer):

 

Dad wrote:

Hi son,

IT200’s can rattle along for a while without blowing up. Cyl head stud holes were made out of cheese, will strip if you look at them, used to time-sert all of our race bikes cyl head studs.  Bottom engine mounting bolts used to strip.   Piston clearance max 004”.  The tighter the better with slow run in (full tank of fuel).  Answer muffler & 310 main jet made them run well.

Get those ribs checked out.

Regards

 

 

Rattle sound can be subject, so I would pull the cylinder and confirm you are within 0.004" clearance using bore gauges and mic and inspect the rings for wear.

Ok, tapped the old and grey wise one who is the IT guru (former IT racer):

 

Dad wrote:

Hi son,

IT200’s can rattle along for a while without blowing up. Cyl head stud holes were made out of cheese, will strip if you look at them, used to time-sert all of our race bikes cyl head studs.  Bottom engine mounting bolts used to strip.   Piston clearance max 004”.  The tighter the better with slow run in (full tank of fuel).  Answer muffler & 310 main jet made them run well.

Get those ribs checked out.

Regards

 

 

Rattle sound can be subject, so I would pull the cylinder and confirm you are within 0.004" clearance using bore gauges and mic and inspect the rings for wear.

 

Well there is a lot of truth in what you posted there. I dont agree with the head bolt thing though as we never had a problem. That could be from the lack of torque wrench use and over tightening?? The answer silencer and 310 main jet is spot on though.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now