03 YZ 250F missing part - EXPERIENCE PLZ!!

[Dirtcrasher]

Hey guys, just got this running for a bud of mine. It had 2 year old gas and it was my 1st experience with these awesome thumpers. All it took was a good tank, petcock and carb cleaning. I started it and the exhaust would smoke? He said it leaked oil and didn't know why and my investigation ensued.....

So, I found this bore/opening (just behind the blue hose) and a 10MM bolt that appears to have held the missing object...... It doesn't POUR out which is weird?? but it drips dam well...............



The online parts diagram shows nothing. Looks to me that it could be for an oil cooler?? or external something? I looked at the WR 250 thinking maybe that would show it but nothing was there. If so, the oil ought to BLAST out of there no?????????? I'm lost kids..............

To me it just gets a cap but I'm unsure if the 10MM bolt holds it in place and or what the heck has happened here. I'm trying you guys before Thumpertalk, it should be chicken for you guys that work on these but I have no clue what it's for myself.

THANK YOU for any help as I'm LOST

BTW, this answers my question about 250F's having enough power. This thing in STOCK FORM is a rocketship

[Jason Hall]

DC, that Is the plug for the compression release arm that was stock on the earlier YZ250F. It has an O-ring on the shaft/plug In your case, that seals the plug. The plug comes out the front, and has a machined groove In It. The bolt your looking at has a round tip that fits Into the plug to keep It In.

[Jason Hall]

Been working on this between Many other projects



Here Is an 02 compression release arm. Notice the bolt has a Copper washer on It.

[MonroeMike]

Here's some manuals for that bike, if needed.

http://www.mxguy.com/motorcycle-main...al_01-16-2008/

[hondawasaki]

The newer bikes have the compression release built into the exhaust cam. The stock plug is rubber, but you can get a nice billet aluminum one from the aftermarket. Those stock rubber plugs blow out all the time on the 450's, and the newer head castings don't even have a hole machined in the head.

[Dirtcrasher]

Thank you both....

Pics and manuals are always helpful!! Thanks for taking the time to help....

Jason, that part is not shown on the diagram, does this mean he has to buy a junk head to obtain one??

There is a large diameter bore about 10MM deep and then a small bore a bit deeper. The bike is not here anymore so I'm going off of memory, I should "see" this plug/cap in there I would think.....??

If it is in there, it's in deep and the oring must be bad.

I wonder why though, if there is NO PLUG, that oil doesn't pour out of there unless it is in a splash area and not a pressure area??

EDIT - If it's rubber than it must just be a splash area, thanks for the heads up!

I may just have to machine one up on the lathe. I gotta try and find a picture online so I know what I'm dealing with. Or just find a decomp shaft and cut off all the useless areas

[Jason Hall]

Here's the part. I found this for a 03 YZ250F, under the Camshaft Chain. Number 13 Is the part your talking about.

http://xtremeusa.com/fiche_section_d...2003&fveh=7103

[hondawasaki]

here is a billit one made by ZipTy racing Ty Davis's company...

http://www.ziptyracing.com/products/...px?id=MTAwNg==

its on the top of the list.

[Dirtcrasher]

^ Thanks very much!! It's hard when you have no idea what your even looking at

Any idea if the rubber plug is available? It's not shown on the fiche which means my Kawi dealer will be useless. My buddy is broke (couldn't even pay me 75$ for the 3 hours of work I did..... So, a rubber plug would probably be more to his liking.

[hondawasaki]

It definitly is, looks like it's 3.60 from bike bandit.

13: PLUG,SPEC'L SHAPE 349184-001 Enter 0-99 $3.60

http://www.bikebandit.com/houseofmot...f-2004/o/m8865

Being a guy who has owned these bikes, I would spend the 15 bucks and get the aluminum one. The rubber plug isn't held in by that bolt, and they bail all the time.

Edit, its cheaper on the site that Jason posted up. only 2.53 there LOL.

[Dirtcrasher]

YES YES!!!!!!!!!!

Grateful!!!!

Go figure, it's in the "head" but not in the head diagram.....

Thanks for the legwork guys

[outtaline]

Man you should get a manual before you screw something up. You think you are god or something.Don't foreget the search at the top of the page so you can quit wasting peoples valuble time. j/k lol couldn't help it, didn't want this to get out of hand, somebody has to give you crap

[Dirtcrasher]

Back to this again......

My bud wnated a quick fix, got the rubber plug and I used permanent setting compound on it AFTER clening the bore spotless... Still fell out but everyone siad it would.

I'm have ready to machine the prick myself

I'll check the links on these and he wants a "Metal Mulisha" graffix kit too.

I'm straight out right now, so if you guys just happen to know where I can get both for him and shipped in one shot, let me know please!

Take care,
DC

EDIT - WHY is this plug NON-EXISTENT on EBAY? I need the kit and plug - no profit for me - just helping a bud. FRUSTRATING!!

[Tri-Z 250]

GO to Thumpertalk.com the billet part is $10 shipped last I did my HotCam conversion to Auto decomp Cam on my 01'426f. Besides the site is good for parts and Yamie Experts over there to boot.

[Dirtcrasher]

Thanks to all!!

It's a tough plug to find and I got it from ZipTY racing. There machining may be off just a couple thousandths, it fits, but the oring groove may not be machined just right IMHO. I had that bore as clean as a whistle yet I had to tap in the oring, it just seemed maybe .002 too tight for me.

But, it's done and thanks to everyone

That stock cap is useless.............