New here! 50cc build

[DieselTech]

So here is what I found when I pulled the head off. It does not look like the gasket is damaged. The head bolts seemed tight, but I had not checked them on the last two rides. The oily side of the gasket is the down side to the jug. I have not pulled the jug yet, just look-see so far. I welcome your observations and comments on what you see? I am learning one mile at a time! Thanks

Your head gasket wasnt sealed all the way around by looking at head gasket, if this website would only let my draw on your pictures I could show you the problem area, the surfaces need hand lapped true.

 

[DieselTech]

In your pics of head gasket, the gasket was not sealing at the top of gasket in your pictures between the 2 top bolt holes. If that makes any sense to you.

 

[DieselTech]

Pictures may be deceiving me to?

 

[Risk Man]

In your pics of head gasket, the gasket was not sealing at the top of gasket in your pictures between the 2 top bolt holes. If that makes any sense to you.

thanks.. I will take a look with that in mind. I am going to hone on glass. Should I do the jug top also (remove it) or just the head?

 

[Chainlube]

So here is what I found when I pulled the head off. It does not look like the gasket is damaged. The head bolts seemed tight, but I had not checked them on the last two rides. The oily side of the gasket is the down side to the jug. I have not pulled the jug yet, just look-see so far. I welcome your observations and comments on what you see? I am learning one mile at a time! Thanks

Is that piston flat on the top? @DieselTech that gasket looks like it was sealing all the way around to me, there is a little oil seepage from removal on one side. The up side has a good impression of the cylinder all the way around, shows good even torque. Half the time the gasket will be crushed on one side and not the other, the crushed side had the big kid on the production doing the torque on that side.

 

[Karl Snarl]

all it needs is a tickler to prime the carb.

You tap the bottom and it tickles the float and releases some gas. It's so you know there is gas flowing.

 

[DieselTech]

Is that piston flat on the top? @DieselTech that gasket looks like it was sealing all the way around to me, there is a little oil seepage from removal on one side. The up side has a good impression of the cylinder all the way around, shows good even torque. Half the time the gasket will be crushed on one side and not the other, the crushed side had the big kid on the production doing the torque on that side.

To me, but like I said the pics could be deceiving me, but the head gasket to me appears it's not getting the same amount of head gasket crush all the way around the bore, to me it appears that in top of picture between the bolt holes in head gasket it was getting a lighter crush on the head gasket. I would at least try lapping the cylinder head if he didnt feel like messing with the jug at this time. I keep going back & studying the pics, maybe wasnt leaking per say, just a light gasket crush on that side of the head gasket or improper torque as you mentioned.

 

[Wrench]

I've seen this happen on Whizzer M/Bs
Did the head gasket leak on the exhaust side? It's hotter on that side
The head bolts lost their torque not because they cam loose but because the aluminum head bolts holes shrunk under the nuts and or the aluminum threads in the cyl or case stretched from heat during the first torque down forces.
IMO is common with China aluminum heads and cyls.
The head bolts on new engines need to be re torqued after the first 50 miles and maybe again after 100 miles

 

[Chop-chop]

So here is what I found when I pulled the head off. It does not look like the gasket is damaged. The head bolts seemed tight, but I had not checked them on the last two rides. The oily side of the gasket is the down side to the jug. I have not pulled the jug yet, just look-see so far. I welcome your observations and comments on what you see? I am learning one mile at a time! Thanks

By looking at the oil stains at the top of your jug, there obviously a compression leak at the head gasket. Get yourself a torque wrench and torque up your head bolts in 2 or 3 stages when the engine is COLD. DO NOT listen to the clowns that tell you to do it 'by feel' - I don't care what anybody says, a torque wrench is the ONLY way you will be 100% certain that your head is on correctly with minimal chance of leaking.

If you decide to go the whole hog and use a copper head gasket, make sure you use a blow-torch or the stove-top to heat the gasket up to soften the copper to help it seal properly.

 

[Chop-chop]

To ensure proper bolt tension without the chance of stripping the threads from the soft aluminium case, I drill out the threads and install steel helicoils into the case to hold the head studs, I do this for a peace of mind when torquing down the head. In fact, I do this for my exhaust studs as well to ensure consistent sealing where possible...
You can pick up one-size helicoil kits for under $10 bucks off Ebay, so I grab the M6 and M8 kits to do most of the studs on the China girl considering the poor quality of the casting on our China girl engines...