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Who Do You Fine Folks Recommend For Valve/Head Work?

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I recently purchased a used YZ250F with a bad motor. As part of my diagnostics, I pulled the valve cover & checked valve clearance. No valves are zeroed out at this time, but the right intake valve is .0025". All still have cold clearance that I suspect would quickly zero out once the engine warms up.

 

Now here comes the interesting part, I removed the spark plug, brought the piston up to TDC, removed the 2 rubber plugs on the left hand side of the engine, and put a smoker into the spark plug hole. After it ran for a few minutes I find that smoke is coming out of the air filter (leaking intake valves), and also out of the 2 rubber plugs on the left hand side of the case (worn piston & rings, or gouged cylinder).

 

No smoke from the exhaust at all. So, looks like I will be pulling the top end and replacing at least a piston, rings, wrist pin, circlips, gaskets, and maybe cylinder re-lined if it is damaged. I also apparently need new valves, and valve seats need to be cut as even when closed, they are leaking back into the intake to the carb.

 

Who do you guys recommend for cutting the valve seats? Do you buy your own valves & ship them with the head, or do you just let the shop do it all? Do you recommend swapping to stainless steel valves, or go back with the titanium? New springs required? How much should I budget to cut the valve seats & replace all intake valves? I can do my own assembly once the seats are cut so should I just let a shop cut the seats, press in new valve guides, and then do the rest of the work myself to save on labor?

 

Lastly, since I need to replace piston & rings, do you advise going up to the 13.5:1 piston?

 

Any advise is appreciated at this point.

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What year is the bike? Where do you live?

Only have a machine shop who uses a Serdi type valve and seat cutter. Hand cutting the seats is unacceptable. Any reputable machine shop should have no issue doing this for you.

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I had A.P.E Racing cut in my valves- around $100

Ebay OEM full valve kit- $325

Ebay OEM piston kit - $160

 

Put a new cam chain and cam chain tightener on as well. Another $50 or so. Also look into either the TT store or hondatoledoeast.com. I sent the head, base and the full valve kit to A.P.E. so they could hone the cylinders and mill the head. Talked with Jeff over there, good guy.

Edited by morphrider

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Thanks for the info everybody. I plan on sending the head out to have the seats properly cut by a shop that knows what they are doing. There is a KTM dealer advertising on E-bay that they will cut the seats for $85. Since they are a dealership I am expecting there to be a catch like excessively expensive valves, or whatnot on top of the $85 so I'm hesitant to send it there.

 

I would rather choose a shop that specializes in head work, and just have them cut the seats, and then assemble them myself. So, APE racing sounds like they will be getting a phone call from me.

 

As an update-I got the head pulled and the cylinder looks perfect. No scratches, no gouges, no other signs of damage. Still see a cross-hatch pattern in the cylinder.

 

The head on the other hand, I filled the intake ports with water and immediately started seeing water come out around the two outside valves. So, intake valves are definitely shot. Will call APE and see how they recommend moving forward.

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I used this guy for my head last year. I forget exact price, but it was reasonable and he is a cool guy to talk to, etc. If you send em the head and valve components, he will cut the seats and assemble it all to make sure its all good to go. He will also shim the valves as required so when you get it back, you just have to put the head on, timing chain, etc. Just make sure you send your shims with the head because what he does is keep those and give you w/e ones your newly re-done head needs...straight swap basically. Just make sure all the components you get are compatible, ie the valves with the retainers you get. If you get all OEM it would all be correct for example. He also told me to hold off on guides initially, and he would check them out when he gets it all apart. So basically he would need valves, springs, retainers, and locks and would let you know if you need more which you could find at a price you like and send to him.

 

http://www.zforcemotorsports.com/

 

Guys name is Tim. And he does use a Serdi.

Edited by J_YZ2fittyF

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Okay, next question.. Where is the best place to buy a valve kit to include springs, new valves, seals, guides, etc;???

 

Are the exhaust valves titanium like the intake valves? I see kits being sold that include only new springs, valves, & seals for the intake side.. Since it is only my intakes that are leaking, can I get away with just reworking the intakes and leave the exhaust valves alone?

 

I am shipping the head off tomorrow to Fastheads. They are going to call me after they have inspected it and let me know what it needs to repair it. Hopefully they are not going to try and sell me a new head, or sell me parts that equal the cost of a new head. We shall see.

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Ebay is often the place to find it all the cheapest. And yes they are all titanium, however the exhausts dont move as quickly as the intakes most of the time. If money was tight or you knew you may only keep the bike for the rest of THIS season....you could just do the intakes. That is assuming the exhausts have never moved. If you plan to keep it for a while, it may be worth doing it all at once when you think about having to take the head back off, re-sending it out, etc, etc....should the exhausts begin to move say 25hrs from now. I guess it is nice to have piece of mind the WHOLE thing is fresh, but its not an absolute must.

 

Also a lot of the kits I have seen on there are valves, springs, retainers if I remember correctly. I believe the shop should be able to tell if you if it looks like the guides need to be replaced. They do not always have to be. I would also buy new locks as well (little tapered semi-circle things that keep the valve from falling right out of the retainer and into the cylinder).

 

Lastly, I think in the classifieds here a lil while back...I seen a guy who was selling oem valve components. May be worth looking through there and if you can find the ad, see if he still has any of it and how much, etc.

Edited by J_YZ2fittyF

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I just got the full OEM kit off eBay. $325 for everything included in valve job. Do them all for piece of mind then put on an hour meter so you KNOW how many hours are on the new head job. Ya I said it......head job, lol.

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Morph this is not a bike I plan on keeping. I bought it cheap to either flip it, or part it out. Honestly it looks like it is going to make me more money parting it out than fixing it. I estimate $750 to fix it (including all parts, labor, shipping, fluid) + what I paid for it. Even in good running condition what can I expect to get for it?? Maybe $1500? I checked locally and these bikes are only getting around that in good used condition. Granted I'll have receipts showing a complete valve job, new piston, rings, gaskets, wrist pin, etc; but still the bike won't bring more than $1500 I'm guessing.

 

Anybody need any parts off this thing? If I get enough interest in parts, I'll go that route.  Unfortunately I think this bikes fate is sealed. It's a shame too because everything else on the bike is in tip-top shape. New tires, new gold link chain, new Sunline sprockets, works connections frame guards, new plastics, new Pro-Taper grips, new One Industries gripper seat cover with no tears or damage.. The old owner tried to keep the bike looking good but apparently did not plan or budget for the engine side of things. Now I see why he sold it.. Who's the sucker here? Oh wait, it's me.. Ha ha ha! At least I can laugh about it.

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Plans have changed again. My brother, who has been bugging me to find him a bike, gave me the go ahead to fix the bike and he is going to buy it off me when it's done for what I have in it. So, back on track for repair.

 

I really did not want to part out such a good looking bike, and now I don't have to!

 

Morph, I'll tell you I got the bike for $400... I think it amounts to about 1 monthly payment on the old owners new KTM..  The guy acted like his KTM was being offended because this bike was in the same garage.  Not a problem for me.   I'll have $1250 or so in it total when I am done and that's exactly what I'll ask my bro for.  Plus I get the joy of building another engine (which i do truly enjoy).

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Just ordered a Pro X piston kit on Flea-Bay. Head is being shipped off tomorrow morning through UPS. Now the waiting game on parts to arrive.

 

Will have to wait for the shop to call me after they inspect the head to see exactly what it needs. I'm saying a quiet prayer on that one.

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