Exhaust valve issues

[Sledhead613]

i just recently had my 2010 rmk 800 rebuilt , putting it through its break in 50:1 in the tank, I decided to pull my exhaust valves off today to see how everything is looking ,there is now 80km on the fresh top end with new cylinders , I noticed that I the guillotines were slightly chipped on the edges I’m wondering what could cause this and what can I do about it ? Do I need new valves or can I just file them down slightly , there is also a mark on the cylinder where is was chipped is it safe to run like this ?

 

[retiredpop]

The exhaust valve stop that limits how far the valve can go toward the cylinder bore has worn. You can see the stop that is cast into the cylinder if you look in there with the valve removed. Over time that stop gets pounded down and allows the valve to go too far. Cheap and easy solution is to grind down the corners of the valves to give it some clearance. Other solution is to buy new cylinders.

 

[Sledhead613]

The exhaust valve stop that limits how far the valve can go toward the cylinder bore has worn. You can see the stop that is cast into the cylinder if you look in there with the valve removed. Over time that stop gets pounded down and allows the valve to go too far. Cheap and easy solution is to grind down the corners of the valves to give it some clearance. Other solution is to buy new cylinders.

Okay thanks that’s what I Figured, but also this is a refurbished cylinder from the dealer I would think they would check things like that before using it

 

[AdrenalineAddict]

I've found that relying on the dealer to check things like that will never happen. I recently picked up my rebuilt 2018 from a well established dealer, ran it on the trailer and found out nobody bothered to put any ant-freeze in it. We did the fill and bleed (roughly 4 quarts), then took it for a spin. When I got back to the trailer I smelled antifreeze, closer inspection revealed only one of the 3 bolts at the thermostat had been tightened more than finger tight. You have to go over all work anymore with a fine tooth comb. Now I'm really paranoid, if everything I see is done wrong, was anything done correctly, were the rings installed upside down???, were the circlips oriented correctly???, how many of the cylinder or head bolts were torqued correctly???, how long did they run it in the shop with no antifreeze???, were the pistons even installed the right direction????? I guess I'll eventually find out.

 

[retiredpop]

Okay thanks that’s what I Figured, but also this is a refurbished cylinder from the dealer I would think they would check things like that before using it

Yeah, I don't know if they just re-plate the jug and call it good or actually check everything. It would be pretty difficult to add material to the valve stop I would think.

 

[mtncat1]

Okay thanks that’s what I Figured, but also this is a refurbished cylinder from the dealer I would think they would check things like that before using it

if its a a refurbished cylinder ask the dealer how he wants to replace it .

 

[Sledhead613]

if its a a refurbished cylinder ask the dealer how he wants to replace it .

That is what I’m going to end up doing and replacing it myself this time lol