YX140 head gasket

[gtrtorana]

I have just recieved the gasket kit for my YX 140 to finish off my top end build and the head gasket that come in the kit is like a shim and is nothing like the original one that I removed form the engine. Is this gasket OK to use? I know it will increase comp ratio but I dont want the thing to leak oil or blow a gasket when I am in the bush. Any help appreciated.

 

[sean01]

who did ya get the kit off, thats a zongshen 140 kit... should be ok to use tho

 

[gtrtorana]

Thanks for your quick reply. I will have to check for valve clearance if I use this gasket as it is pretty thin and it will have to increase comp ratio. Will I need to add any sealant for the oil gallaries? Am I better off just getting the right head gasket?

 

[gtrtorana]

I have been recomended to use Hylomar so I will give that a shot.

 

[sean01]

yeah hylomar was going to be my answer lol...

the gasket isnt all that much thinner so you should be ok

 

[gtrtorana]

Yeah, thanks for that sean01. The shim gasket is around 0.030 thou thick and the original one is about 0.080 thou thick. Anyone have any ideas what the head nut tension is?

 

[cloud_2901]

Tight, but not so tight it snaps? Don't know exact torque settings for this engine but your arm is a better torque wrench anyway if you can feel when a bolt is going to snap.

Just seat the nut fully and give it another 45 - 60 degree turn after it has seated, warm up and check that its still tight after the warmup.

If it's worrying you, go down to the nuts and bolts store near you and get a bolt the same size, and tighten it in a random piece of aluminium with a hole in it until it snaps the bolt, then you'll work out when to stop! That's what they made us do in TAFE, snap a few different bolts in a few different materials, so you get a feel for how NOT to do it.

 

[Carlts]

12NM for the head mate, recheck and tighten afterwards mate!

 

[gtrtorana]

Thanks for the tips guys but it all turned pear shaped. Bolded top end on, all went well. Started bike and she ran well. turned it off and left it for the night as it was late by the time it was finished it. Get up the next day, go to kick it over and the kick start gears failed. Pulled side cover off and there is a huge crack in center housing. I am going to rebuild this engine as a spare but I want to get another one in the mean time. Can anyone tell me the difference between the Zongshen 140 that DHZ sell compared with the YX engine. Pros/cons between the 2 engines? I have ported the head on my YX engine, can I bolt this straight onto the Zongshen. Any help would be great guys.

 

[sean01]

zongshen 140 seems to be a very good engine, next to zero problems that iv seen.

you must have the early yx140

both the engines are pretty much the same, zonger have just dont their bit to fix some issues. crack cases is one thing..

the head should be exactly the same so you can put it on.

if i was to choose between the 2 engines id have to pic the zonger 140

 

[gtrtorana]

Thanks for the info sean01. I have put my order in for a new zongshen. I purchased my YX140 in early 09 and I have given it a hard time and it did perform well. I will look for a new center housing and repair it in the future. I do have one more question, does anyone know if the cams are different in the zongshen compared to the YX?

 

[sean01]

iv never compared the 2 cams so cant say..