Engine woes... Bent Exhaust valves... and....

75 replies to this topic
  • JohnnyAirtime

Posted April 07, 2004 - 12:50 PM



Here's the deal.
I'm trying to keep my honest mechanic honest. Since I'm not a 4
stroke mechanic... and don't wanna be. :)

I recently had been losing about a quart of oil every 200 miles. In
fact .. I posted about this about a year ago I think. (wow.. it
really was a looong time ago). So I had a mechanic pull the motor
and yank it down to see what's up. Ultimately... it was pretty tired.
Mostly from dune riding. (a tad of sand does horrible things to these

So I replaced EVERYTHING that said "seal" in the engine as well
as "bearing"... let alone a new Barnums Cam and piston, rings,
Carillo rod and crank assembly...etc. The bike went together... and
once started was a tad noisy. Noisy... like it was a CRF.

I still took it on a ride... It didn't sound too bad, and it went together super
nice and smooth. SO.. I rode it! 80 miles in fact into Mex. And...
the damn thing lost most of it's compression within 10 of those
miles. But it still started. So I kept riding. At the 80 mile mark...
it died. Yup... died. I could bump start it (this is after I took all
kinds of things off or checked to make sure it wasn't something
stupid) and it'd run... but not very good. I ended up towing it for
about 30 miles of the 80. Then said screw it and rode it to the

Once apart... I was told I had bent exhaust valves. Bent??? What
the??? Anyway... being we were both busy at the time, I didn't get
why or who's responsibility it was.

SO here's what I'm asking; (finally huh?!)

1- Were the valves bent ya think due to timing being off??
2- Ideas??

Thanks in advance... I truly am bummed. I haven't ridden the XR in
a loooong time. 10 months or so!!!

Johnny J

  • BlueRules

Posted April 07, 2004 - 01:06 PM


I dont know about the bent valves but it sure sounds like the mechanic screwed up, go him!

  • qadsan

Posted April 07, 2004 - 01:44 PM


My guess is the mechanic who put the engine together didn't check clearances and take into account thermal expansion. The exhaust valves get super hot. As things heat up, they expand. It's not uncommon to dish the crown of a piston via grinder to make room for the exhaust valves when running a performance cam. Hopefully you'll be back in action soon enough with a bike than runs better than ever :)

  • JohnnyAirtime

Posted April 07, 2004 - 01:54 PM


Wow... second reply with the same answer.

And I bought the cam from Rob at Barnums Pro Products. He's an awesome guy to work with... I'll call him to see if he mentions this issue.

I've got a mild cam grind (from Rob as well) and I know that may also effect the clearances... we'll see.

Thanks for the help.

  • frogman

Posted April 09, 2004 - 01:05 AM


"Not wanting to be" a four stroke mech is gonna cost you some $$$ Johnnie....

I have not needed to break down my BRP yet but it sounds like cam chain might of been off a tooth or clearances bad.

Kick that Dudes ass!

  • frogman

Posted April 09, 2004 - 01:05 AM


"Not wanting to be" a four stroke mech is gonna cost you some $$$ Johnnie....

I have not needed to break down my BRP yet but it sounds like cam chain might of been off a tooth or clearances bad.

Kick that Dudes ass! :)

  • JetPilot

Posted April 09, 2004 - 02:51 AM


A mistake was obviously made somewhere. You did go with a non stock cam that could have affected things for the worse, question is should the mechanic have caught this ? I can see him maybe not wanting to eat the cost of the parts, but he did do a total rebuild on the motor and should carry some of the responsibility. The fact that the mechanic is charging you his additional LABOR to correct this mistake just really sucks. Your mechanic sounds like a real sleezebag.

"NO FEAR" If you have no fear, you didnt go as fast as you could have ...

  • JohnnyAirtime

Posted April 11, 2004 - 07:18 AM


Thanks guys.. I appreciate any help you offer.

Just to clear the air... please re-read the post. I think some things got misconstrued. I see Frog asks about the motor being newly rebuilt. Yes, the mechanic took it down to nothing and rebuilt it. All for a killer price as he knows friends of mine and helped me out. And Jet... he's not a sleaze bag and hasn't charged me. He's a straight up nice guy with great mechanic talent. All that's happened so far is I bought the parts and dropped them off with the bike. We haven't discussed a price or even if he'll charge me on the fix.

SOOOoo... With that, like I said... I was just looking for advice on what might have been wrong to cause the problem being the motor was brand new top to bottom. AND it ran fine for the first 10 miles. THEN... it started to lose compression when I kicked it over. AND.. if the mechanic should eat any costs or offer up his labor and parts cost since IT WAS just rebuilt. That's all! :)

Does that make more sense??

  • JohnnyAirtime

Posted April 21, 2004 - 01:04 PM


At this point... I appreciate all your comments. I think there were some definite things to have looked at... and some things that were misconveyed now that I know clearance would or could have been a huge problem....

I was trying to work out the issue with The Barnums (Denise mostly) of Barnums Pro Products... but it seems there's more finger pointing going on than anything. I'm gonna give the Barnums a day or two to offer a better resolution as this forum only knows half the story on the total chaos I've recently dealt with... It deals with not only the valves, but a cam gear... and other things.

I'm sure you'd all be very surprised to hear and read what I've been told...

Stay tuned.

  • JohnnyAirtime

Posted April 26, 2004 - 08:20 AM


well.... I've posted the 'whole story'... you can view it in the "general" postings;

TITLED: Barnums... and a bad experience

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • irondude

Posted April 26, 2004 - 02:22 PM


Johnnie :D airtime,

Why is it barnums fault your mechanic is just a parts changer? Couldnt he hear the valves hitting the piston when he started the bike after re-building it? Monkey. What about the rod, the gaskets, the vavle clearence? Its a freakin race engine...you dont just bolt it together and go to Baja and ride it till it dies. gimme a break. Did you put oil in it?????! You a monkey, not Barnum. Barnum a former team Kawasaki mechanic. D 37 #1 plate holder. Hard working small business man. Honest and good guy who supports our sport. You a snivelling little girl that tried running with the big dogs and fell on your face.

Why is it Barnums fault you took a ticking bike to Baja and rode it till it died?

I point the finger at naive johhny :D air :D time.
He needs a good slap. :)

  • JohnnyAirtime

Posted April 26, 2004 - 02:49 PM


Oh gawd... Iron Ass again!?!? :D

Being I just replied to you in the other posting... I've got to tell ya... You are a #1 supporter of MAJOR ass kissing!!! :usa:

I hope Rob discounts your next motor rebuild... He does do your work right? How embarrasing as it sounds like you know more than anyone out there. :D

Like I said, I don't doubt Rob's ability at all. Maybe you need to "read between the lines"... oops, you did already. GO back and re-read... maybe you'll understand your 5th time through. :)

And I'll line up with you anyday. But if I'm faster... does that make you a slow ass monkey?! Ahh, I wouldn't give you the time of day. I've already replied to you too much and taken too much of my time with you.

Have fun at the 500. Make sure to listen for odd noises before you ride. Like voices in your head. Karma works wonders. And... those booby traps... oh, they're a doozy when not heeded. Lastly... make sure we don't see a DNF on final results. :D :D

Good luck Iron Butt.

  • irondude

Posted April 26, 2004 - 06:48 PM


Just for the record:
For the past 4 years i have been paying full price to Rob Barnum. I say positive stuff about his shop becouse i have had such a positive experience. I respect his efforts as a small businessman, a 650 racer, and a great mechanic.

If you check the archives you will see that the one time i did have trouble with a Barnumpro issue (it was a clogged Edelbrock carb) i did bring it up on this forum.

SO little john-john, you are--once again--wrong. I am well known on TT for calling it like i see it. No sugar coating. Straight up. My two pesos are that Barnumspro.com is the best overall place to go for XR650 stuff. He is the only shop at the races, he's a thumpertalk supporter, and IMHO an honest small businessman giving it a go.
John-john---i learned most of what i know about bikes from my father. He is a mechanical engineer who started racing desert in 1970. I grew up making my own expansion chambers, racing 70's mini mx, and riding "Gorman" before it was a ORV park!
As for my knowledge of the 650--i have said time again that i wish i only knew half of what Qadson knows. I am the guy to go to for info on racing BITD and SOCRE/Baja. The insights i have on the 650 come mostly from reading the internet--but also from racing the bike, and from working as a Baja guide for Chris Haines, and now with Tim Morten of Bajaboundmoto. And finally, yes, from Rob as well.

You stand corrected.

Johnny :cry:air :cry:time...

  • RidesRed

Posted April 26, 2004 - 09:08 PM


Sounds like your mechanic, like yourself, isnt a 4-stroke mechanic either. Fire him. He is clueless. Any 10th-grade autoshop student understands about piston-to-valve clearance. We all make mistakes. Even competent mechanics make mistakes. But a competent mechanic would have caught that mistake before you ever started that engine. Sorry to sound so harsh, but thats the reality of the situation. The mechanic is the sole person responsible for proper engine assembly. So don't blame Barnums pro. Seems to me your total ignorance of 4-stroke assembly procedures is causing you to fix blame where it ought not be fixed. Fix the problem, not the blame. And the problem seems to be your "honest" mechanic. I'll take a competent mechanic over an "honest" one anyday. If anything, your mechanic owes you for his sub-standard workmanship. And you owe Barnums-Pro a HUGE apology.

  • JohnnyAirtime

Posted April 27, 2004 - 02:14 AM


I think the obvious is now being overstated.... sure it's the mechanic's fault... and mine ultimately. However... if you understand fully what's going on and don't hone in on the valve issues... then you'd see just exactly where the entire problem came from.

I find it even more interesting how I'm getting emails from supporters, but they don't want to post on the forum due to harassment. That sucks. Too much finger pointing and badgering from people like IronDude.

And Quadsan... nice informative person. With a lot of knowledge. I'll take info from him any day... especially since he doesn't throw it out there and belittle people like IronDude (who has no right since he knows nothing of me personally).

So... let's not beat the dead horse already. As you'll read, I'm not "blaming" Barnums directly for anything but bad customer service.

  • TimBrp

Posted April 27, 2004 - 07:00 AM


I can relate to both sides of this. Johnny while your mechanic did overlook the obvious, aparently multiple times, I think the time spent getting the parts is absurd. However, as a small business times are tough. With this bike there are few and far between "knowledgeable places". I've called Barnums once or twice for advice and they helped out great. However, I think they're over their heads a tad with regards to parts availability and delivery times. I got quoted 2 months for a carb?? &%$#@! is that? Start a business, people get hooked, sure supply and demand are going to skew. You happend to have a bad experience, however most haven't. They corrected your crank issue from what I read, though. You got porked in your eyes man, suck it up and move on. It happens to the best of us. I'm dealing with a mechanic that threw me a cheap price and alot of chatter on how good he was with rebuilding fourstrokes(xr250/spare) and now I've got a totally rebuilt engine that blows blue smoke full-time, yeah &%$#@! right. I'm sucking it up and bringing it elsewhere. Sometimes things are too good to be true. Live and learn.

  • JohnnyAirtime

Posted April 27, 2004 - 08:47 AM


Yuuup... I'm sucking it up all right. :) Sorry to hear about your issues too. But isn't best if you let us know who's giving you problems so we don't use him/her?? Or use with caution I should say. :D

The good news, my piston wasn't damaged nor were any other parts. :D So I'll have a bike that runs this weekend... maybe to enjoy some "Weekend Street Warrior" time... with a tad bit of dirt. I've got too many other things to do to ride Mex again this weekend. ..blah.. ..blah..

  • TimBrp

Posted April 27, 2004 - 02:57 PM


I have let people in my area know of my "frustrations". Particularly, all my friends willing to bring work to this place and the great price it was. There are really only a few good places you can go to and be satisfied with a mechanical job and how it works in this sport. It's a wicked expensive/addictive hobby and we typically go for the deals. However, technology increases and alot of shops are stuck in the 80's. I'm not saying I doubt your mechanics skills, he's probably really good. I think more mechanics would thrive if they had Obsessive-compulsive disorder in this sport. Things would be done twice and work right the first time. However, time presses and things are missed/looked over. Like I said "live and learn". Don't go back looking for a fight you know you'll lose. People will learn and if the business is trully bad then they'll lose in the end.

  • JohnnyAirtime

Posted April 28, 2004 - 03:29 PM


Very true... very true...

Hat's off to ya for one of the most mature replies I've read. (maybe IronDude can learn from it). Anyway...

Back to cleaning my bike. :thumbsup:

  • TimBrp

Posted April 28, 2004 - 03:38 PM


Thanks...However, I'm not getting into the thing with you and Irondude... :thumbsup:

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