BRP Down

[Riley16]

Well, my exhaust valve had been acting up for the last while. After about 40 minutes of riding the clearance would set itself back to zero. On my last ride, I was just pulling on to my property when she just quit on me. I tried turning it over, and there was some knocking, and the exhaust was sucking in air. After that I walked it home, pulled it apart, and this is what I found:

I'm going to see what honda quotes me for a fix, but I'm thinking it's going to be well beyond what I'm willing to pay.

The other option is to get a used motor and swap it in. Does anybody have a good source for used/refurbished motors for these bikes?

Has anyone else had a similar problem with their valve cinching up?

If I had a Honda flag, I'd lower it to half mast.

Oh well, it's a learning experience if anything.

03 XR 650L with desmog, opened air box, UNI foam air filter, Dave's mods, 55/160 jetting and Clarke fuel tank

[condershire]

That head can be repaired, may cost a bit of coin, however.  Send some photos to the folks at Engine Dynamics or XR's Only, heck, even a local machine/welding shop may be able to do something with it...

 

The problem with buying a used motor is you never really know what you are getting into unless you tear it down, factor the cost of buying a new head, valves, piston, etc. and things add up quickly...  If you can find a used motor with LOW miles it might not be a bad deal, but they'll want upwards of $1500-$2000 for it...

 

Don't feel too bad, I've had 2 dropped valves within the last 6,000 miles....

 

Here is what you are probably looking at:

 

Head repair: ~$150-$300 (just the damaged area, tig indentations and cleanup, which is what I would think a shop would do)

Valves, possible seat, etc: probably another $300-$400

Might as well do the piston as well, figure another $50-$80 for boring and $150 (tops) for piston/ring set

Gaskets: ~$75-$100

This is assuming we are not going into the bottom end, which should not be necessary...

 

Somewhere around $1,000, probably less but no less than $750...

 

A GOOD used motor will cost at least $500-$750 more and you have no idea what you are getting...

[DarylInAjax]

^^^ what he said...totally agree.

 

You'll pay less to repair what you have and in the end will have a freshly rebuilt motor that should serve you well for years.  A used motor could be good...or another nightmare, and won't last you nearly as long as one with a fresh rebuild.

 

I'm going through this myself at the moment...I don't have the kind of damage you have (I blew out my base gasket) but on teardown I discovered a pile of things the PO did improperly when he rebuilt the top end.  It's going to cost me about $600 to get everything right but at least I'll know the motor will be in awesome shape when I get it back together.

[ThumpNRed]

Get a used head on eBay and drive on. An XR600R will work and they are more plentiful. You will lose the ability to run the smog crap with the XRR head, but most have removed it anyway.

[Riley16]

Yeah that seems to be the way to go. Honda quoted me $700 for a new head, so a machine shop is the way to go on that for sure.

If I end up fixing it I'll probably get a new cam chain cause I think it may be stretched.

It looks like the PO had been in here as well. I'm thinking it's unusual for this to occur at 20000km (12500 miles), so I don't know what he bunged up in there.

I see an 05 XRL head on eBay for $450, and that includes the valves and everything. I'm thinking that's probably the best option, but I'll see what the machine shop quotes me. May as well rebore while I'm at it too!

Thanks

03 XR 650L with desmog, opened air box, UNI foam air filter, Dave's mods, 55/160 jetting and Clarke fuel tank

[Riley16]

Ok, so this is what I've found on eBay:

- Cylinder head w/valves off of an 05 $450

- Wiseco 101mm 10.5:1 piston kit $160

- ProX cam chain $75

- Cometic gasket kit $40

- Plus the cost of boring and honing ~$100

I took a look at XR's only for parts too:

- 103mm 671cc piston kit (ceramic coated or not?) $209 or $245

- 103mm gasket set $32

- K&L cam chain $90

As far as the piston goes, if I'm re-boring I may as well go big. Does anyone know if the ceramic coating is worth it? And does a 103mm bore have any negative implications, maybe with respect to the CV carb or valve sizes?

I'm actually getting excited now over this beast I could create. I just have to try not to get too carried away haha.

03 XR 650L with desmog, opened air box, UNI foam air filter, Dave's mods, 55/160 jetting and Clarke fuel tank

[Onederer]

As far as the piston goes, if I'm re-boring I may as well go big.

 

 

Have you thought about what happens if it needs bored again?

 

There is usually enough in a stock cylinder to go a couple oversizes before the sleeve needs replaced or using another cylinder. If you go for the max the first time around, next time you'll have to buy another cylinder or have the sleeve replaced, either way next time is going to cost more because of it.

 

Higher compression and a thinner cylinder are going to cause the engine to run hotter too. Have you thought about what caused the problem to begin with?

 

If you are set on cranking up the power, you should really consider some additional engine cooling if you want it to last. I am partial to the oil cooler option because if you go the big fin head route and the head gets wiped out again, you may have wrestle with getting it repaired or chunk it. Trash the engine as many times as you like with an oil cooler (not that it will happen) and the oil cooler is still ready to rock,although it may need flushed out depending on the nature of the engine damage.