Head studs

[Down Under XC]

Hi Guys,
I picked up an 83 XC 250 from Indianapolis in the US. Very original condition and have just started going over the bike. The guy I purchased off has a few huskies and prefers the pre 83 models. By the time we finished the transaction he invited me to ride in the vets series in the US on one of his pre 83 huskies. How good is that ****************************************!!! Unfortunately time and distance will be the killer but just shows what great people are out there associated with the husky brand.

Anyway starting the restoration process and pulled the head and barrel and noticed pitting and rusting on head/barrel bolts and partially damaged base gasket. This would appear to be because the contact area under the head/barrel nut was not 100%, ie only 65 -75% due to the milling process. from my perspective every time it is high pressure washed water and dirt will be forced into head stud area. Not good.

Should this contact area be cleaned up so it is 100% ???

Thoughts comments from husky community appreciated.

 

[jimspac]

I would repair the pitting with epoxy instead of planning that surface. You can adversely alter your port timing unless you maintain the stacking height by removing enough depth to utilize 2 base gaskets to restore the stack height. If the surface is not flat enough for the gasket to seal, it will cause an air leak leading to piston seizure. You may need a height measurement to restore to if it is already low. I can get you a measurement to maintain from that surface to the top tangent of the installed crank wheel from the 250WR I am putting together

 

[Down Under XC]

Hi Jimspac,
Sorry I wasn't very specific, it is the flat surface where the head/barrel nuts bolt down on the head that are not 100% in contact and hence when torqued up allow water and mud to ingress the stud bolt area and hence damage the base gasket area. Well that's where I reckon the water has got in.
Still epoxy in these valleys would solve the problem.
thanks


Mark

 

[jimspac]

If you have access to or happen to own a spot face tool, that would nicely clean the faces the head nuts are torqued to

 

[Down Under XC]

Hi Jimspac, I had the barrel and head water blasted (cleaned up) and then bored to suit new wossner and then I had my engine machinist do as you suggested and I have had the bearing surfaces all spot faced (still some minor surface imperfections but will fill with either epoxy or grease).

Just out of interest are you still running the standard carb, some here have gone to a flat slide ??

What mods if any have you done to springs (rear) and front forks. Change of springs etc ??

Thank you

Mark

 

[Desmoducky]

If you are looking for reasonably priced replacement studs, try using Volkswagen air cooled engine studs... they work perfectly. I paid three bucks a piece for them.

Desmo

 

[ct cr430]

My 81 cr430 is the same may . This is a small gap between the cylinder and the head that you are questioning , right ? My cr430 does not have a head gasket and relies on a lapped surface between the cylinder and head for a seal . If you are asking if that gap between them when looking at the engine from the side should be machined closed , how would you be able to lap the head to the cylinder without remachining that surface everytime . On mine , I am putting a little silicone on the hole after the cylinder is in place . Just enough to try to keep dirt and water out from between the studs and cylinder but not so much that I can't remove the silicone next time it comes apart .