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Xr200r decompression question

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When I bought my '90 xr200r it needed a new top end. When I took it in, I was there with the guy when he started tearing it down. Upon removing the rocker cover and getting the cam out, found another problem. 

The kid I bought it from said he put a new cam chain in. Well when he put it together, he didn't ensure the dowel on the inner bearing stayed in the hole, so yeah, he cranked everything all down and destroyed the journal. I called and looked around for another head and cover in good shape but no luck. Then I learned that the head from my old '81 atc200 was the same thing, so I lucked out and didn't have to spend any money. 

The only thing different was that it has a manual decompression lever and not set up for the cable to work with the kicker, no hole to mount the bracket. I'd like to get the cable back on so I don't have to reach down and flip lever when needed.

My question is, can I just drill and tap a hole to mount the bracket to hold the cable? I mean it's essentially the same rocker cover, so as long as I don't drill too deep and use a bottoming tap, I should be fine right?

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So I was going through stuff I've posted and came across this one. I noticed there have been 180 views but no responses. 

Thought I'd bring this back up to the top and revive it in hopes of a response. I'm pretty sure I already know I can do it, I guess I'm just looking for verification?

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 On the Curtis Sparks 200x (3 wheeler) motor I'm putting in my vintage sled I swapped the X set-up over to the R set-up, straight bolt on. Here's how: "R" valve cover, including "R" exhaust rocker, on "X" head (has all the stuff for the comp rel.). "R" clutch cover (ditching all the "X's" forward kick assembly stuff) on "X" crankcase; (again, all the comp rel. stuff). "R" kick start shaft (I used the "X's" kicker & ratchet gears). The "X" and "R" use the same clutch cover gasket. Uh,,, and cable to hook up the comp release. VOILA! 2 wheeler motor. I had the whole 3 wheeler so I swapped the chassis (even) for the "R" parts at the local scrap yard. Free, straight trade. Nice.

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  Still gotta mill off the foot peg mounting lugs from the "X's" crankcase before I stick the motor in the chassis. Don't need em and they'll probably be in the way of the lower frame cradle. (plus get rid of those few ounces of "road hugging weight")  ;)

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Thanks for the responses guys, but I don't think anyone's understanding my question. 

The motor has already been rebuilt, the head and rocker cover on it currently, came off of my '81 atc 200 (not 200x). It has the manual decompression lever already. 

I want to put the kicker decomp cable back on, but the rocker cover doesn't have a hole drilled for the clamp that holds the cable in place to work properly. My question is, can I just drill and tap the hole where it would go? 

Everything I've been told, you shouldn't mismatch rocker covers and heads since they're made together, so I haven't put on the R cover. Is it really not that big of a deal?

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  Yeah, I've heard you're not supposed to mix heads/rocker covers but I did and it worked out fine. Sounds like chadzu did too, so I'd say; "go for it".  :)

 

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  Or go ahead and drill and tap the cover that's on there. But, like you said; "be vewwy vewwy careful".  ;)

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2 hours ago, Daniel627 said:

Thanks for the responses guys, but I don't think anyone's understanding my question. 

The motor has already been rebuilt, the head and rocker cover on it currently, came off of my '81 atc 200 (not 200x). It has the manual decompression lever already. 

I want to put the kicker decomp cable back on, but the rocker cover doesn't have a hole drilled for the clamp that holds the cable in place to work properly. My question is, can I just drill and tap the hole where it would go? 

Everything I've been told, you shouldn't mismatch rocker covers and heads since they're made together, so I haven't put on the R cover. Is it really not that big of a deal?

 

1 hour ago, Doogee57 said:

  Yeah, I've heard you're not supposed to mix heads/rocker covers but I did and it worked out fine. Sounds like chadzu did too, so I'd say; "go for it".  :)

 

 

The reason it is desired to keep the two pieces of the head together is that they are machined together when the cam bearings are bored.  This holds true with any type of head like this, heads with top covers, caps for bearings, etc...........motorcycle, automotive, industrial or whatever.  Two piece connecting rods are this way also.  The reason you can get by with swapping on these is the fact that clearances are so sloppy.  You can grab the end of the cam on a brand new engine and move it around several time as much as the valve lash you are supposed to have...................!;)

Old School Al

Edited by Old School Al
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I think I'll just drill and tap. Be quick and simple. It's essentially the same cover as the R.

I'm afraid that when the kid cranked down on the original one, he might've tweaked it, so I'll throw it in with the rest of the aluminum going to scrap. I'll get another head and rocker cover when I decide to get the old atc motor running

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12 minutes ago, Old School Al said:

 

 

The reason it is desired to keep the two pieces of the head together is that they are machined together when the cam bearings are bored.  This holds true with any type of head like this, heads with top covers, caps for bearings, etc..  Two piece connecting rods are this way also.  The reason you can get by with it on these is the fact that clearances are so sloppy.  You can grab the end of the cam on a brand new engine and move it around several time as much as the valve lash you are supposed to have...................!;)

Old School Al

Right, I understand the keeping them together because they're machined together, which is why I haven't used the old cover or just picked one up on eBay. 

I'd heard it wasn't the worst thing in the world to mix. Just wasn't aware of why, so didn't wanna try

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3 hours ago, Doogee57 said:

  Still gotta mill off the foot peg mounting lugs from the "X's" crankcase before I stick the motor in the chassis. Don't need em and they'll probably be in the way of the lower frame cradle. (plus get rid of those few ounces of "road hugging weight")  ;)

I believe only 1 or possibly 2 of the peg bosses hit on newer frames.

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   I'm putting the motor in a 1979 RM125 frame that I've modified to fit. I'm gonna trim them off regardless. I've been a machinist for 35 years and have free access to a full shop so it's no biggee. I've got my 88 XR and my CRF250 that I ride so the vintage sled is just my "keep me outa trouble" tinkering project and I'm kinda going overboard making trick, one off stuff for it.

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