XR4 Valve Adjustment

CPT Jack

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#1
I picked up a Honda Service Manual for my bike, but it's really not thorough enough that I feel safe at trying this. Any tips? Is this an easy enough job that I should be able to do it? (I'm a generally unskilled mechanic :) )

Thanks! P.S. - this is regarding my thread on Bogging/Choking!
 
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#2
I would agree that the Honda manual is pretty vague, at least for us mechanically challenged people.
After much debate I decided to take mine to bike mechanic that I felt comfortable with and pay the $40.00 bucks to have it done.
It was much easier and then I didn't have to worry whether or not I was going to foul it up.;)
 

Wolf

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#3
Ditto

I decided to do the same thing. I read the Honda manual and am not comfortable enough to do it myself yet. I'm taking it o the shop and watch them do it and hopefully learn that way.
I do know that there are plenty of people here that do it all the time and they will probably declare us incompetent for going to a shop:o
 

Rodzilla

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#4
You need to find a buddy who is confident doing it to show you how, you'll be amazed at how easy it is (at least on an XR)

Rod
 

mtngoat

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#6
Hopefully Rich or ochster will weigh in; they seem to possess the best expertise. Untill then, I'll relate my experience ( which very well may be controverted)

I'm the "de-facto" amatuer mechanic for several XRs and have done valve adjustment several times. Here's my tips:

Motion Pro makes a great guage, which is bent and narrow and fits nicely into the access port. I've tried standard feeler guages and bent them to fit, but they're too wide and made it difficult for me to get flat and avoid a bad adjustment.

Alignment for TDC is well expressed in the manual. I was impressed how easy Honda made the access and alignment of TDC; just pay particular attention to avoid going the wrong direction, even a little, as it could actuate the auto-compression release causing a bad exhaust valve adjustment. You just need to go all the way around again if the crank slips the wrong direction when aligning the "T" mark.

What isn't clearly expressed in the manual is how "snug" to tighten the adjustment on the feeler guage. I went conservative the first few times and later "snugged" more since the valves were a little noisy. Best I can express it is to avoid so tight that you can feel the spring, but go tight enough that you have to pull the gauge out, as opposed to sliding it out with little to no resistance. Forum wisdom seems to recommend erring the the loose side if you're not sure.

Finally, ochster "educated" me on the possibility (apparently moreso on newer engines) of decreased lash caused by valve seating. Knowing this, I'm re-checking adjustment on the newer bikes more frequently.

Personally, I recommend doing it yourself, since you'll be more inclined to re-adjust more frequently.
 

CPT Jack

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#7
$40?

That would be a done deal for me. I called the local Honda Shop and they told me $160!:scream: I'll have to do some more calling around.
 

SFO

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#8
160.00 dollars?
Maybe you told them you wanted to watch?
 

mtngoat

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#9
Try Three Brothers racing or Champion Honda in Newport Beach. I think they'll be much more reasonable
 

fremontguy

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#10
I did the adjustment on my XR4, all it took was the special feeler gauge and a torque wrench. I was suprised at how easy it was, just follow Honda manual. My valves were all a little loose first time.
 

KWJams

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#11
The hardest part of adjusting valves on the XR400 is removing the spark plug
so she will turn over easy.
Study the exploded view of a top end and figure out how the parts interact together, then it is easy to visualize the procedure---wax on--wax off. :)
 
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#12
For $160 I'll adjust the valves the chain and WASH the bike :)

Mtngoat's explanation pretty much nailed it, but if there is a specific point in the manual that is unclear you should post that so we can better understand where the sticking point is. The basic point to remember is, a little too loose is better than a little too TIGHT.
 

mtngoat

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#14
Cpt Jack,
If you'd like to come up for the next Big Bear ride, I'd be happy to adjust your valves before the ride.
 

CPT Jack

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#15
Done!

Thanks mtngoat, that sounds like a deal! I've been wanting to check out Big Bear too. Sounds like fun. I rode some really tight & nasty singletrack in the Los Angeles National Forest by Gorman yesterday & it was pretty cool. (man, am I sore!) Great scenary & the climate at altitude was really nice.:cool: When are you planning the ride? As long as it's not on a drill weekend I'm there!