Author Topic: Leaking coolant arond cool head studs (Read 6437 times)

JasonB · « **on:** April 15, 2014, 09:43:03 PM »

Just did new rings in my 310 ESR bike. All back together and running but after it warms up and coolant gets flowing it's dribbling around a few of the head studs. The nuts are all torqued down accordingly. Did I jack up the outer oring? Bike doesn't appear to be charging the coolant system, so eithe the outer oring is not in right. Downs that sound possible? New issue for me, not sure wtf is wrong but I did install a new set of new orings . Thoughts ? Thanks in advance!

Turftamer · « **Reply #1 on:** April 15, 2014, 09:55:45 PM »

I would think that if the outer ring was damaged, you'd see coolant leaking from between the head and the cylinder. The studs are not sealed from the cooling system. The head nuts and washers are the only seal. Maybe you could put a thin film of RTV on each side of the cylinder head washers?

udontknowme · « **Reply #2 on:** April 15, 2014, 10:21:24 PM »

you might need to use acorn nuts if your not already and be sure theyre long enough so the stud doesnt hit the top inside. im assuming you have copper washers ? may have to use alittle rtv on them. im not sure of any other way

mx250r91 · « **Reply #3 on:** April 15, 2014, 11:41:18 PM »

The studs on an o-ringed head are not sealed off from the coolant jackets like on a head gasket setup thus acorn nuts and copper or aluminum sealing washers are needed. The OEM Honda acorn nuts work good and for sealing washers use Honda OEM 90442-028-000 WASHER, SEALING (8MM).

rsss396 · « **Reply #4 on:** April 16, 2014, 09:33:25 AM »

udontknowme and MX250r91 are correct you MUST run accorn nuts or they will leak

Rupp250 · « **Reply #5 on:** April 16, 2014, 09:39:41 AM »

I think these are the ones I have, can't remember off the top of my head.

http://www.mcmaster.com/#standard-copper-washers/=rk81d0

Let me know an address and I'll drop some in the mail if I have enough left.

JasonB · « **Reply #6 on:** April 16, 2014, 10:45:06 AM »

thanks guys! I already have acorn nuts in place, just called honda up and they have an order for me for that part number listed in this thread. Should be in tomorow, those washers were like a buck a piece! pretty happy if this solves the issue. I have never had leaking issues and I have had the head off twice to swap domes. oh well, thanks for the info guys! And thanks fo rhte offer RUPP!

rsss396 · « **Reply #7 on:** April 16, 2014, 11:21:52 AM »

with acorn nuts i have gotten away with no washers and just a little copper anti seize

wilkin250r · « **Reply #8 on:** April 16, 2014, 02:22:48 PM »

I had an engine years back with a milled head and o-rings, and because everything was cut down the head was thinner, so the studs extended too far to use acorn nuts, so I had to use regular nuts. Coolant wasn't leaking around the copper washers, it was coming up through threads and out the top.

I could have cut down the studs and used acorn nuts, but I decided to try an anaerobic sealant. It was a Loctite thread sealant, but I can't remember the exact name. It's basically like teflon tape in liquid form. It worked great.

jcs003 · « **Reply #9 on:** April 16, 2014, 03:51:40 PM »

also, make sure the head is flat. if it is warped it will cause issues. always good to lap the surfaces when it is apart.

john

JasonB · « **Reply #10 on:** April 16, 2014, 04:11:50 PM »

I aint lapping crap!! that stuff is for the birds lol. Besides the bike ran before i pulled the top end, just had like half the compression it should have! I was at little sahara and had a 'filter malfunction' we will call it

. Bike started running choppy on the top end so I was like hell just throw a smaller main in there! did and the bike still ran funky. at that point the rings were like half as thick as they should have been just around the exhaust port. Rest of both rings looked fine, they were just ate up around the exhaust port. anyhow, cleaned everything up and tossed some new rings in there she runs great again. I will do a full tear down in the fall and split the cases to go 330 or 350. That'll do pig!

I cant remember now, but i thought i had washers on it before. I ran a set of washers I thought were what came off it when i took it apart. obviously its leaking around them now. Theres no chance i just had the nuts bare no washers is there? ESR doesnt run their heads like that i dont think

Pumashine · « **Reply #11 on:** April 16, 2014, 04:16:20 PM »

Quote from: JasonB;31664

ESR doesnt run their heads like that i dont think

The top ends always come with copper washers or washers with a copper coat. Sounds like they just got set aside.

JasonB · « **Reply #12 on:** April 16, 2014, 04:47:23 PM »

ya Jason Hall and I yanked the top end off in the parking lot at Little Sahara 2 weeks ago because he thought the rings were just stuck with sand in the groves of the piston. I thought everything was tossed back into the same container but its not surprising they are MIA lol. Oh well, nwe ones coming and Honda thinks they will be in tomorrow. Thanks again for the help guys!

udontknowme · « **Reply #13 on:** April 16, 2014, 11:05:18 PM »

with copper washers and acorn nuts you shouldnt have any leaks unless the oring grooves were machined wrong but you said the head worked fine before so you should be good. coolheads ive seen had washers included. ya lapping is for the birds. unless you had a melt down your head should be fine

JasonB · « **Reply #14 on:** April 23, 2014, 10:05:03 AM »

installed the new washers, no leaks! Thanks guys