[Mike.McD]

Some details about the quad that I know. Sorry for the lack of info, I've only owned it two days.

2001, It has a .40 over bore and an HMF Full exhaust.

She's getting hot, and I think that the Carb might be running lean, causing this. It will run great then after some longer sprints she'll start to stumble and miss. I let it cool down and went back out, same thing but this time i see oil smoke coming up from under me. Eased it back to the truck and shut it off. I don't know what size jets are in it. and I haven't pulled the spark plug yet. However I blew a seal while I was riding today, so some work is in order.

Here's some pictures of the damage that I can see from the outside. As far as I can tell It's just leaking oil out of the crankcase/cylinder seal.

 

[Fastas]

nice looking ride, im not to familiar with why it would be running hot but im sure ppl will be posting soon

 

[Atlanta]

There are a few reasons for a air cooled motor to run hot.

1 and most common you are running lean so richen it up,jet it and air fuel screw adjustment.

2 oil pump is not flowing like it should and while its not enough for bearing failure yet it is still enough to not cool the motor like it should.

I would look at jets first and adjust it from there,check your plug,if its white then your way lean it's carbon build up and will kill your top end.

Also be sure the oil is the proper oil and replace it and filter asap.Run a lighter oil to help with cooling,maybe.

These are just some things you can do other then adding a external oil cooler.

That will save you $$$$ big time.

 

[Mike.McD]

How big a job will it be to replace the seal that I blew out?

 

[Helmut]

How big a job will it be to replace the seal that I blew out?

I agree with Atlanta. I would pull the spark plug and check the color of it. It should be a light brown or tan color. If it's white, it's running lean.

The valve cover, head, cam, and cylinder jug will have to be pulled off to replace that gasket. It's not really all that hard, but the biggest thing will be putting the cam back and putting it in time. If you don't have a repair manual, there is a free downloadable manual at the link, below.

maxmekker.com

 

[mud99]

The 400's already have a oil cooler on them.

 

[Atlanta]

The 400's already have a oil cooler on them.

Well sounds like his aint working,lol.

 

[Billy250X]

I'd say that it is deffinetly not jetted properly.So many people don't really understand how the jetting works.Does it backfire or pop on deacceleration?

 

[Mike.McD]

No, it doesn't back fire at all.

Any idea what size jets i might need to step up to? Also who makes a decent jet kit?

 

[Atlanta]

As far as jets go,I would first see what I had,then look at the plug.

If its not a air fuel issue the plug should help with this.

Black and wet is either oil or fuel,smell it.

white is carbon and very bad.

If its white go bigger,buy 2 or 3 and try them.
If you want to also help put the air box on if you have it and slow down the air flow some to help with running lean.


Trying to go fast on a budget will cause your problems and separate you from either money or your atv.

 

[Mike.McD]

Pulled the plug. Black but not wet. Looks and smells like oil in the combustion chamber. Also some oil in the airbox.

 

[Billy250X]

Your rings are probably toast.Does it smoke out the tail pipe when running.

 

[Mike.McD]

No, it doesn't smoke at all out of the exhaust.

Went to Honda this morning and ordered a gasket and ring set.

-Mike

 

[Billy250X]

Well keep us posted.

 

[Atlanta]

Looks like your running a tad lean with maybe some old valve stem seals.

Try a slight gap adjustment in your plug.

And maybe up your jet.

 

[Mike.McD]

Got everything torn down today. Apparently the PO was an investor in RTV, shit was everywhere. The rings look ok but I might as well replace them and re-hone the cylinder while its all down.

Found the source of my leak.

State of the garage.

Hopefully the parts will be in tomorrow and I can get this back together.

 

[Billy250X]

Yeah everything looks good to me.

 

[Helmut]

RTV sealant is the worst thing you can use on gaskets. The excess will squeeze out on the inside of the engine. When it cures, it will be rubbery and if it breaks loose on the inside of your engine it can stop your oil pump up. I learned that the hard way, years ago. If you need to use sealant on your gaskets, use Hondabond. It doesn't cure rubbery and it costs about the same as RTV sealant and you can buy it at your local Honda dealer. Even when using Hondabond, you only need a thin coat.

 

[Atlanta]

I use 3m glue to hold my gaskets in place prior to assembling everything.Keep everything lined up as it should be.

Your motor looks fine,hone with a light grit hone,no med or heavy,fresh rings and gaskets.

I also take and soak everything in a bucket or parts cleaner or hydrofluoric acid to remove old gaskets and clean everything.
Clean parts seem to work better for me.

Let us know how it goes.

 

[TRX2fiveO]

Wow that engine has been ran Rich for quite awhile bro just by looking at the carbon build-up on the piston but it's always better rich than lean. I would replace the piston since you're already there at it budget permitting of course. What's that Pontiac sitting behind it? LeMans? or Firebird? looks nice. Keep us posted on the progress, nice pics.