350X slight oil leak!! Need opinions and answers.

[ClayW]

Ok, on my 85 350X there is an oil leak. Im not sure if its the head gasket or valve cover gasket. Maybe you can help me. I have never torn into one of these engines before. Nor a 250. The leak is coming from the front side of the motor. Ok This is where the leak is. You know the part that you take off to adjust the valves. The small cover. Its leaking between the piece it bolts to and the next section of the engine below. At the level of where the spark plug screws in. Not the small covers gasket. I know I sound like an idiot, but again I have never torn one down. I have a 250es motor that I plan on tearing down to learn on. Is it the Head gasket? If it is the head gasket is it a bear to change. Do you have to make sure the engine is at top dead center before you change the gasket? I know you dont have to take the timing chain off to get to this area. I plan on buying a Honda manual soon. I have one for my XR500R and I know it is very similar in design. Any help would be appreciated. GIve me some tips, ideas, pointers.

ClayW

[jeswinehart]

yep ,,, it's the head gasket clay. manual says you need to pull the motor to get the head cap off ( part with the valves in it ).
and yes ,,,, you will want it at top dead center so as not to screw up the valves upon reassembly ( or disassembly too as far as that goes ) . i beleive that is true on all 4 stroke motoers.
i'd reckon it to be a half a day job clay if you don't run into other weido things ( header bolts froozen ,,, throwing your back out of wack from lifting a x motor in/out of it's frame ,,, those kinda weirdo things )

qone reason i have found that head gaskets blow out is a plugged up tail pipe. i kinda dought that's the cause though since you have said your header is toasted but you might want to check it out.

want to borrow my manual for a spell ??? gotta keep it clean is all i ask.
( ain't no finger smudges in it )

john

[hrc200x]

If the thing is aluminum colored and held on by 2 10mm bolts its the valve cover, this would be just a o ring that is bad, unless its cracked. There is also another valve cover located towards the back/top of the motor under the tank, which coves the intake valves.

The next thing in that area that could be leeking would be the head cap which holds the rocker arms, there is no gasket there, the shop manual says to use liquid sealant.

http://www.boreal.org/~kimball/donemotorright.jpg in this link you see the round rubber cap right below the air scoop? Right through the middle of this is where the head and head cap meet. you can actually see the orange liquid sealant I used. The headgasket would be located right above the exhaust sheild in the pic. You should be able to see the head gasket on your motor when its together, since the gasket is made out of metal.

Only thing I could think of is when taking off the head cap is to have the motor on the compression stroke so no pressure is on the valves.

top dead center is found by removeing the small timing plug from the flywheel cover and aligning the T with the small notch in the hole. http://www.boreal.org/~kimball/done350xleft.jpg you can see the aluminum timing plugs in that link. They are located right above the shifter. when the large timing plug is removed it exposes the fly wheel bolt so you can turn it over to align the T.

[MO350X]

Ok, on my 85 350X there is an oil leak. Im not sure if its the head gasket or valve cover gasket. Maybe you can help me. GIve me some tips, ideas, pointers.

ClayW

Clay, get a manual ASAP!

I can't emphasize enough how important it'll be for such a technical repair.

Mine is a copy of the factory Honda original.
Got it off of ebay.
Great seller, great copy, great price. He sold it to me for $20 outright.
It comes with three holes punched so you can stick it in a 3-ring binder-VERY handy for thumbing through while working on the bike!
A bound copy can be a pain in the butt to keep open to a specific page without trashing the binding.

Here is the link to his auction:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=34237&item=7920511148

Take your time, follow the manual and you'll do just fine!

[ClayW]

Ok. The leak is where the head and headcap meet. Thats definately where its leaking. The dip wad that had it smeared somekind of sealant allover it and JB weld in a few spots. So is it pretty straight forward? Do I have to remove the engine to fix this? I know John said with a head gasket you do, but what about this? What kind of sealant did you use.

ClayW

[ClayW]

Thanks MO350x. I have delt with this guy for my copy of the BIG RED manual. The guy is a lying A-hole. I paid him instantly, and it took 2 weeks to get it. He said it had already gone out, It was going out, and it should be there tommorow and he hadnt even sent it. Said he lived 2 hrs from a post office. Anyway Im sure it hasnt happened to everyone. But he and she are a lying jerk. I told him just tell me the truth and I can deal with it. Sorry for the rant. But some people. Anyway thanks for the info.

CLayW

[Howdy]

Ok. The leak is where the head and headcap meet. Thats definately where its leaking. The dip wad that had it smeared somekind of sealant allover it and JB weld in a few spots. So is it pretty straight forward? Do I have to remove the engine to fix this? I know John said with a head gasket you do, but what about this? What kind of sealant did you use.

ClayW

From what you have posted, the oil is leaking from the top cap. In between the top cap and the head there isn't a gasket or o-ring. To seal this cap Honda uses a compound ( I don't know the name or part number ) for this stuff ( I use Hi-Tac for the ones I work on).
It has been some time since I removed one but I am thinking you can remover the top cap without removing the motor. Get the motor to TDC and make sure the lobes of the cam are pointed downward ( towards the piston ). Then remove the dozen or so smaller bolts holding the top cap on. Remove the top cap and clean the 2 mating surfaces. I use ascetone myself. I then apply a thin coat of Hi-Tac on both surfaces and re-install the top cap. Adjust your valves and you should be finished.
This whole job should only take about 2 hours ( or less ) your first time.

I hope this helps.
Howdy

[ClayW]

Howdy thanks for the info. I really appreciate it. I guess I will tackle it before long. Thanks again for the help.

ClayW

[jeswinehart]

well crap ,,, i was sure you was talking about the head gasket. my bad.

clay ,,,, you want to use my manual for awhile ??? heck, you might be able to use a copier to duplicate it.

you will need to give me your address again ,,,, i got delete happy.


john

[ClayW]

Yeah John why dont you send me that manual, and I will copy it up at my office. I will get it right back to ya. I will PM you my address. Got the fork boots today. Thanks a bunch.

ClayW

[jeswinehart]

it'll be heading your way in the morning clay.

glad to be of some real help ( lol )


john