Hawk 250 Cylinder Head Question

[VirginiaRider]

My Hawk has an oil leak between the cylinder head and barrel. I took the cylinder head off of the engine to replace the gasket, but I found that the bolts holding the cylinder head on were different. Only 3 of the 4 bolts had a spacer and only one of the 4 had a rubber o-ring on it. Pictures of the top of the barrel are attached.

Is this normal? Am I missing a spacer and 3 o-rings? If so, is it safe to leave the engine disassembled while I wait for the required parts to arrive?

Any help would be greatly appreciated!

[Megadan]

Only 1 O-ring, which is in the one in the picture is required. That location is where the main oil feed to the head goes through the cylinder and head area to get to the rocker cover where it drains down on the valves and rocker assembly.

If you want to get a new O-ring, you can use Honda part number 91301-200-000 or locate a nitrile rubber O ring 10mm x 1.6mm at your local parts/hardware store.

Since that is the only location oil can leak from, I would personally replace said O-ring just to be safe as it may have a crack or nick in it causing oil to seep past. I bought a 5 pack just to have extras on hand because I take my bike apart so much lol.

As far as only having 3 dowels, that is also normal. You could order another one and use it, but realistically speaking it isn't necessary.

If you are going to store it without the head on, it would be a good idea to at least cover the jug with a bag or cloth to keep dirt and other junk from getting into the rings.

[VirginiaRider]

Thank you very much for this information!

[Megadan]

Originally Posted by VirginiaRider

Thank you very much for this information!

Happy to help! When installing the new gasket just be careful not to damage the thin bead of red silicone that comes on them that goes around the pushrod holes. This is another area where oil can potentially seep past over time as it is the main drain down area for the oil coming off the head. I smear a very thin layer of semi-hardening gasket maker around this area to ensure a good seal. That part really isn't necessary, but I prefer to not have to take things apart again. The only drawback is that it makes the headgasket not re-usable, which isn't a problem for me as I don't like reusing head gaskets, but that does matter to people that do.

[thederrick106]

I just installed a new head on my 2015 hawk I am building into a rat rod and was pleasantly surprised at how simple these motors are!

[Deckard_Cain]

Originally Posted by Megadan

Only 1 O-ring, which is in the one in the picture is required. That location is where the main oil feed to the head goes through the cylinder and head area to get to the rocker cover where it drains down on the valves and rocker assembly.

If you want to get a new O-ring, you can use Honda part number 91301-200-000 or locate a nitrile rubber O ring 10mm x 1.6mm at your local parts/hardware store.

Since that is the only location oil can leak from, I would personally replace said O-ring just to be safe as it may have a crack or nick in it causing oil to seep past. I bought a 5 pack just to have extras on hand because I take my bike apart so much lol.

As far as only having 3 dowels, that is also normal. You could order another one and use it, but realistically speaking it isn't necessary.

If you are going to store it without the head on, it would be a good idea to at least cover the jug with a bag or cloth to keep dirt and other junk from getting into the rings.

I recall CSC techs telling many of us when we install the tt250 metal shim HG that the O-ring is not required- is that only when junking the stock MLS gasket?

Because I've been running the thinner HG for a good while now and no o-ring. lol.

-Jason.

[Tractor Tom]

Good info here. I would also suggest you watch a YouTube Hawk top end replacement video. I recently viewed it and it discusses the exact o-ring and other details, Goodol'boys is the name. I think he referenced this forum so he might be a member of this group.

[JohnC]

Originally Posted by Tractor Tom

Good info here. I would also suggest you watch a YouTube Hawk top end replacement video. I recently viewed it and it discusses the exact o-ring and other details, Goodol'boys is the name. I think he referenced this forum so he might be a member of this group.

Here is the link:





Worth the time to review.


John

[Megadan]

Originally Posted by Deckard_Cain

I recall CSC techs telling many of us when we install the tt250 metal shim HG that the O-ring is not required- is that only when junking the stock MLS gasket?

Because I've been running the thinner HG for a good while now and no o-ring. lol.

-Jason.

It might not be required. I wasn't aware of that and still installed the O ring with it. Hasn't caused me any issues.