Was wondering if anyone could help me out with a few things...

I have a 1984 XT600 that I am rebuilding...the head and rockerbox are out of a 1984 TT600 (34B stamped all ovcer the place!) that I bought off ebay and it seems the original XT camshaft is too tight in the journals to spin freely when I tighten down the rockerbox to the head!! ....is the TT600 cam a smaller diameter? Could the cam be severely out of round and binding?

the parts numbers are different for the Xt and TT camshafts but I have read that the XT600, TT600 and XT550 cams are all interchangable....not sure if this is so.....

I am about 3 months into this rebuild and this really has me stumped...I would like to find a TT600 cam and have been searching but to no avail....the head is in great condition and so is the rockerbox....if I swap out the XT cam I wonder if the TT cam has the inner spindle for the tach or not?

One other question as well.....I bought a cylinder I believe is from a TT600 as well...it was at 95.5mm and I had it bored to 96mm........I know the TT was a Nikasil plated bore....but was it a cast iron sleeve plated with Nikasil?
This cylinder has the yellowish tinge around the outside bottom of the barrel but it is definitely an iron sleeve....i used a magnet to determine and it sticks....my question is, is this cylinder ok to run now that i have had it bored out because it is a cast iron sleeve or is it , althought iron, a lighter grade and more susceptible to wear?

Thanks very much for any help you can offer....

Matt


Any input on this would be greatly appreciated.....

I would think the XT cam would fit in the TT head - are you sure there is not something else that is wrong - cam out of round, head / box warped, dirt, fluid gasket etc?
Time to go to a workshop and have things measured up. There are dimensions for everything in the TT and XT workshop manuals.

The original TT's (so, also the '84) had nickasil cilinders, the nickasil applied on the aluminum barrel, no cast iron whatsoever on the thing. So, you definitely have a XT cilinder there. Which, BTW, you can use w/o problems and can be rebored for use with larger piston.

Auke

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Auke,

Thanks for the reply....

I feel better about the cylinder....I had a better look at the cam in the journals...everything is free of any dirt or debris and looks good...spins freely until I tighten it down the last 10 percent....if i loosen the two bolts right over the sprocket end of the cam it frees up again.....although I havent measured it, the cam seems to be out of round on the sprocket end......it was the original cam from the XT top end (which was in bad shape...scored badly..far rocker arm badly worn..)

..the TT top end is in great condition and I dont think it could be warped....my hunch is that the cam is bad....I already have the head bolted down with a new gasket so I think I will look around for a used XT or TT cam and see if it works out....hopefully it will....

I checked out your website....looks like a good time!

all the best

Matt

Hi Matt, please explain again what combination of barrel, head, cover, and cam you want to use.

Everything should work also if mixed, except you CANNOT IN ANY CASE get a head and a cover from different engines, they are paired together at factory. If you mix them, surely the cam will not rotate.

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Hello Cyberzar....

thankyou for that information....I never knew that they were a matched set......this may be the cause of my woes....wonder if anyone has had this issue as so many of these paerts are sold separately on ebay, which is where i got these from.....

barrel is 1984 XT600
Head is 1984 TT600
Box is from 1986 TT600



Matt

Plus... And since you're working on this I suggest you READ THIS!

How Clean is Clean Enough ??

brilliant stuff over there!

Vando

Matt, the problem is only with:

-head and head cover (camshaft can be also from different engine)

-right and left central engine carters


these are paired in factory, so if u'r lucky maybe you can make a pair with two parts from different engines and they work, but it's more probable that you will do BIG damages trying this...

I know someone that assembled head\cover NOT paired. Engine started, and when hot the camshaft locked in the head. As you seee you r lucky because you noted the problem before to start the engine...

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