Honda cb72 oil pressure problem?

[nivolo]

hello everybody
my name is søren and i am from Denmark so hopefully you guys can understand me

I bought (what i tought was) a complet Honda cb72 from 1962. But the engine was far from complet, a hole lot of parts was missing. so i bought a doner engine so now i thought a had all parts for a complet engine. I made a complet engine. Whit new gaskets, bearings, and so on. After the engine was assembled i got it in the frame. I kickstartet it a few times and all seemed fine. But! the next day when i came back to the motorbike, it was dripping oil from the head gasket. I took the engine out and stripped the top of the engine. Both cylinder gasket (top and bottom) was soked in oil. I have been thinking a hole lot the last few days and i can simply not find out why. All bolts and nuts are tightened to the right torque. Please help a confused Dane
doner engine:
[/img]http://www.hondatwins.net/forums/attach ... 154829.jpg[/img]
Oil everywhere on the gaskets:



Just tried to remove the cylinder top and bottom gasket and tighten the 8 nuts on top (just by hand). The cylinder and cylinderhead cant move. So the studs are not to long. All surfaces are straight:

When i turn the engine over just by hand olie is purring out of the hole i marked whit green. No oil is coming out of the red hole. Am i on to something here? I thought the oil should be coming out of the red hole?

[pemdoc65]

The dowel pins with the green o-rings on top of the cylinders seem very short. They should stick up into the cylinder head when you assemble it, and maybe they aren't far enough into the head to make a solid oil passage up to the head.

[G-Man]

Your green hole is the feed from the oil pump into the gallery at the front of the cylinder. The gallery feeds oil into that hole (red) to feed th emain bearing. Oil does not come out of there.

Oil goes up the two corner studs (with the green o-rings) to get to the head.



G

hello everybody
my name is søren and i am from Denmark so hopefully you guys can understand me

I bought (what i tought was) a complet Honda cb72 from 1962. But the engine was far from complet, a hole lot of parts was missing. so i bought a doner engine so now i thought a had all parts for a complet engine. I made a complet engine. Whit new gaskets, bearings, and so on. After the engine was assembled i got it in the frame. I kickstartet it a few times and all seemed fine. But! the next day when i came back to the motorbike, it was dripping oil from the head gasket. I took the engine out and stripped the top of the engine. Both cylinder gasket (top and bottom) was soked in oil. I have been thinking a hole lot the last few days and i can simply not find out why. All bolts and nuts are tightened to the right torque. Please help a confused Dane
doner engine:
[/img]http://www.hondatwins.net/forums/attach ... 154829.jpg[/img]
Oil everywhere on the gaskets:



Just tried to remove the cylinder top and bottom gasket and tighten the 8 nuts on top (just by hand). The cylinder and cylinderhead cant move. So the studs are not to long. All surfaces are straight:

When i turn the engine over just by hand olie is purring out of the hole i marked whit green. No oil is coming out of the red hole. Am i on to something here? I thought the oil should be coming out of the red hole?

[Tim Miller]

Make sure your sleeves are perfectly flush.
The 11mm dowel pins should be 18mm long. Although yours look shorter, that's not causing the oil leak. If that's a aftermarket head gasket? I've had problems with the metal fire ring not crushing enough to make fiber gasket seal around cam tunnel. I only use OEM Honda head gaskets for this reason. Torque head to 18 ft-lb.

Best of luck,
Tim

[nivolo]

you guys are right! of course the dowel pins are too short! cant believe i didn't notice that. I dont remember who manufactured the gasket set but as far as i remember it wasn't Honda. I will try to buy new dowel pins and a new gasket set. I just couldn't rap my head around how it got so leaky, i only kick the bike over a couple of times i didn't even start the bike and then just oil every where.
Thanks you guys for the fast respons and helpful answers!!

[CandyBlue]

Also, check that the surfaces are perfectly flat! You can check on a verifiable flat surface to see if all surfaces on head and jug are in contact with no derivations. I put together a CL77 last year that was out of spec and for $30 a machine shop milled the surfaces for me to make sure they were totally flat. All together now with no leaks! Held og lykke!