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leaking head gaskets

305 nutt
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Joined: Thu Apr 10, 2008 8:54 pm

leaking head gaskets

Post by 305 nutt » Sun Oct 26, 2008 10:02 pm

Hello, I have built 4 honda 305's in the last year. Heres the problem. 3 of the 4 I have run, which all sound fine and run great, thanks to Ed Moores secret recipe on fine tuning, but they all leak oil terribly out of the front of the engine between the cylinders and head. I used the dk gasket kits that are sold on ebay on these 3 and genuine o rings on the 2 outer studs to make sure they are right. I haven't ran the 4th motor yet, it will be awhile but it has a nos aftermarket gasket set in it that was made in the 60's. Now heres where stupidity comes in, After building the engines (I did them all at once as an assembly line) the 3 with the dk gasket kits leaked oil at this location when they were on the bench before I even ran them. I always preoil my top ends quite abit before installing the top covers, so I tried to convince myself it was run off from that, and stupid me put them in the bikes and guess what, yep, they leak like a sieve. Now 2 out of the 4 I surfaced the top of the cylinders and head surface on my work bench (heavy steel top) with 120 grit paper, yes this took a while and wore out several sets of shoulders, but non the less I wanted them right. The other one I did not surface and it leaks as well, so I've ruled out that being the problem. I torqued everything as according to Bill Silvers books, even retorqued them after break in. Do I need to tear the 3 back apart and buy genuine nos honda gaskets? My question is I guess has anyone used the dk set with similar problems, because if so, someone needs to refund my dough for cheap junk. Thanks for the help in advance, if I find that the dk gaskets are the problem, I'll definately post on here for a warning. thanks nutt

e3steve
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Location: Mallorca, Spain & Warsash, UK

Post by e3steve » Mon Oct 27, 2008 6:18 pm

Nutt, seen several remarks about DK head gaskets being inadequate. Gen-u-wine Honda are, allegedly, tho only head gaskets to use. Food for thought for us all!

bj
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Joined: Thu Jun 12, 2008 4:45 pm
Location: Murrieta, Ca

Post by bj » Tue Nov 04, 2008 12:10 pm

I used a DK gasket on the left side cover after I fixed my clutch. After only a few miles it already leaks. I installed it dry. Is there some kind of treatment I could have done to the gasket to help it seal better?

305 nutt,
I feel for ya man, what a bummer. And on 3 motors.

Thanks,

Bryan

e3steve
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Posts: 2601
Joined: Fri Oct 31, 2003 1:38 pm
Location: Mallorca, Spain & Warsash, UK

Post by e3steve » Tue Nov 04, 2008 1:35 pm

It's possibly leaking from porosity between the facings of the gasket rather than from the facings-to-casings themselves. I favour the blue Hylomar liquid gasket, as used by Rolls Royce for decades, but I think ThreeBond is a possibly a favourite in the US. Perhaps it would be more prudent to obtain an OEM set; are they still available or are they just NOS?

305 nutt
honda305.com Member
Posts: 67
Joined: Thu Apr 10, 2008 8:54 pm

leaking head gaskets

Post by 305 nutt » Sun Nov 09, 2008 1:37 pm

I did buy a nos honda gasket off ebay for 40.00 with shipping. Sounds high, but look at the alternative. I believe your right about the porosity of the gasket leaking, if I remember right, I sprayed hi tach sealer by permatex on both sides and it looks like it is leaking from one side of the front of the head to the other. I'll slip the nos gasket on and try it and let you know the results. Thanks for the info, nutt

e3steve
h305 Moderator
Posts: 2601
Joined: Fri Oct 31, 2003 1:38 pm
Location: Mallorca, Spain & Warsash, UK

Post by e3steve » Sun Nov 09, 2008 6:41 pm

Out of interest, Nutt, did you follow Bill's advice mentioned in his HERG?
Attachments
HERG cyl head notes.jpg

305 nut
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Joined: Tue Jan 01, 2008 7:44 pm
Location: north vernon Indiana

leaking head gasket

Post by 305 nut » Sat Dec 06, 2008 3:13 pm

I fianally got the motor back off and apart on my cl77. After disassembly I did do like the book told and put some silicon on the inside edges of the oring area of the gasket. Looking at the gasket, it looks very porous compared to the nos honda gasket. The old gasket was completely logged with oil even on the back side. What a piece of ____ !! I did email the dude from ebay about this tragedy and he said the dk kits are made up of various gasket companies. The head gaskets are vesrah. Wish I would have known that to begin with, my xr200 I rebuilt with vesrah gasket kits leaked at the head gasket. Should have known. Oh well, I'm on my way to recovery. I'll let you know how the new nos gasket pans out. Thanks for the help. NUTT

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