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Xr400 Cam Timing

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Hey guys,

 

Before I put this back together can you guys check these pics to see if this is lined up properly? IMAG0114.jpgIMAG0118.jpgIMAG0119.jpg

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Nice clean assembly.

Photo 1: all cam lobes are down. Put more lube on those lobes.

Photo 2: I'm guessing, the cam gear is lined with the head? If so.

Photo 3: TDC compression . All looks great then.
Slap on the rocker box, gently, torque to spec.
Once all together, set valve lash to spec. I personally like my valves a shade loose(er) than spec. A tappy valve is a happy valve . Plus less chance of burning, and easier to start.
Once that's all complete,
rotate through several times and verify your settings. (Pull the plug, it's easier to turn over. But you knew that.)
Disclaimer: Strictly my thoughts/procedures. I accept NO RESPONSIBILITY if you goof something up!
Looks good though. G.

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all looks good but your cam gear is upside down there should be the 2 marks line up with the head as you have but there should be another mark vertical indicating TDC

did you check the auto de comp before you installed the cam?? I found 2 cracks on mine so I took it off and made a sleeve....check out my thread. auto de comp explained.

and yes more lube I use a squirty bottle to inject engine oil up the cam shaft so it is full of oil on start up.

cam gear 001.JPG

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Hey Vic, I didn't notice the punch mark, and I don't have a service manuel sorry. Obviously the word "out" stamped on the gear means to face outboard. The cam lobes are facing down. That's good.
I do know that on some automotive applications the cam gears have the mounting holes drilled offset which can only be mounted one way. Not sure for Honda m/c's.
Appears I could use a little education also.
Thanks, G

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Well, the holes aren't offset but I can't remember if the sprocket teeth fall the same above each mounting hole.

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I have found some pix I hope they explain better. the OUT mark faces away from the cam and in the proper timed position the OUT mark is at the bottom and out of sight

hence the cam gear is upside down. I don't know if it will upset the timing but I would NOT want to try it. I have taken some pix of my manual on cam timing I hope they help? let us know how you go.....cheers

 

xr400 timing marks.png

xr400 timing marks 2.jpg

cam timing 001.JPG

cam timing 002.JPG

cam gear 001.JPG

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That answers That, jcane88. General opinion and book data indicates that the cam gear is out 180deg. You should research further if in dought, but I'm with the forum members here.

Thank you all for your wisdom and insights and Mr. jcane88 for your question. We all learned something today 🙄.

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Even if the cam sprocket is 180* out, if the picture of it is correct, it wouldn't make a difference, as the sprocket is symmetrical. The top reference line on the sprocket is just that, a reference line. Like if you were installing the cam bolts and got called away, came back later and said, "ok, where was I". Had you turned the cam yet? It's a visual indicator.

As long as you remember that you installed it upside down, no big deal. But someone in the future that may work on the engine may think, what the hell, everything else is lining up per the manual but the sprocket.

Edited by Trailryder42
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Yup, , agree w/that TR42.

Jcane88 did a fine job on the assembly and if this is a first time attempt, cudos to him. And from a learning experience that gear should be made right, I think.
Hell, I'm learning great things every time I chat with you fine folks and Mr.Cane, adjust that gear. You will sleep a wink better tonight.

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yes by all means leave it if you want. its your bike and you have to deal with it. just wanted to point it out so you know about it.

I think its much better to have things right. saves on confusion and headache. agree with Gabe you will sleep better knowing every thing is right.

and if you ever need to go back in there might save scratching your hair out. good luck with it all and let us know how you got on.....cheers

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Thank you for the feedback on this. I will most definitely adjust the according to what the manual and everyone here is saying. I really appreciate all the help.

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good o hope it all goes great... let us know how you got on...cheers

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Hey Guys thank you for the great advise on this. After adjusting the timing again the bike starts reliably! It starts and idles perfectly when choke is on, and it's a bit more chuggy when it's off. I noticed I'm having some loss of power hiccups when taking it around the block for a break-in. Fuel flow issues? I tuned the Pumper carb one turn out on the Idle screw, and one out on the fuel screw as well.

Sent from my HTC 10 using ThumperTalk mobile app

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10 hours ago, jcane88 said:

 I tuned the Pumper carb one turn out on the Idle screw, and one out on the fuel screw as well.


 

One turn out on the "idle" screw? Which pumper carb?

Want to be sure what you're calling an idle screw is actually that.

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Are you talking about the small trickle of fuel thru the fuel line?

Take the tank cap off and see if it's still a trickle. If the tank cap isn't venting properly, you'll have fuel delivery problems.

And even tho the fuel tap is set to ON, vary its position either side of center a little to see if flow improves.

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