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View Full Version : Why haven’t more people done the 200x decompression mod????



bigmike8791
09-25-2018, 08:36 PM
83-85 200x kick start gears are a known problem. The valve cover off a 185/200 (with decompression lever) will bolt up to the 200x (so I’ve read) and solve the problem of continued stress on the gears. Why haven’t I’ve seen more info on this? Seems like it would solve the problem

shortline10
09-25-2018, 08:40 PM
The 200x cam won’t work with the decompression setup and the 185/200 cam is a lesser aggressive cam so your going backwards on performance .

bigmike8791
09-25-2018, 09:14 PM
Thx for reply. Is this Wrong info??? http://www.3wheelerworld.com/showthread.php/91198-200x-Decompression-lever-mod. I hope not because I ordered my valve cover :(

shortline10
09-25-2018, 09:43 PM
The valve cover will bolt on but you will need a cam designed to work with the decompression setup .

bigmike8791
09-26-2018, 09:22 PM
Why special cam? The decompression lever hooks to exhaust rocker. When you move the lever it moves the rocker which presses down on the exhaust valve. Shouldn’t that work?

shortline10
09-26-2018, 09:54 PM
The back side of the cam lobes I believe are machined smaller on the 200x and most performance cams so the lever won’t open the exhaust valve .
Go ahead and give it a try , maybe I’m wrong lol .
I’ve installed a lot of performance cams in the 185/200 series motors and it always caused the compression release to not function anymore .

bigmike8791
09-26-2018, 10:23 PM
Hope you didn’t take my reply wrong? Wasn’t trying to sound like I know what I’m talking about lol. I’m just trying to understand how the lever really works? Not sure what you mean about the cam lobes being smaller. How does that affect the lever not pressing down on the valve? I’m trying to prevent the known failure of the kick starter. Appreciate the info!!

Leevvii
09-27-2018, 01:16 AM
I asked the same question recently , and have a 200 es cover, so im keen to know how this pans out, PLEASE keep us posted. I would assume if it is possible to do it, alot of folks here would have already done it, im not holding my breath but it would be a very handy mod if it is possible. Sadly, i dont think its possible to check the operation of the lever with the motor disassembled, but i might be wrong, good luck. I also assume that the "cam" on the decomp'er uses the lobe of the camshaft as a "pivot" of sorts, to stop it flexing when rotated, so the smaller diameter camshaft lobe would prevent this occurring with the X cam, and hence, no decomp, just a guess.

bigmike8791
09-27-2018, 06:13 AM
Take a look at your cover to see how the lever functions to see what you think. Anybody know the diff in hp between a decompression cam style vs 200x cam? I would think it wouldn’t be that Much? Also would the decompression style cam out of a 185/200e ect be a direct bolt in? To me it would be worth the swap to save the kick start gears. It’s never gonna be a speed demon lol. Maybe upgrade the carb/intake to make up the hp diff. Splitting the case much less finding the upgraded gears would be a pain in the a— . Mine makes a single click noise I’d say 1-2 times out of every 10 kicks, I assuming that’s my gears right? I know I’ve read something about the spring or something. Any info would be great!

bigmike8791
09-27-2018, 08:53 AM
Found this on youtube. Wonder what that grove on the 200x cam is for? Sounds like the cams are interchangeable? Someone with knowledge plz chime in to confirm. If theres min performance difference and its a direct boltin im thinking im gonna put a decompression style cam in. https://www.youtube.com/watch?v=BbNiLAHBynw

greenhuman
09-27-2018, 09:10 AM
If the 200x cam wont actuate the decomp rocker, try using an XR200 cam. They also have the decomp and some blokes use those cams as a cheap performance mod.

bigmike8791
09-27-2018, 10:12 AM
That was my next question. Has anyone installed a xr200 cam in 200 and still had the decompression leval work? I’m hoping townline chimes in as he has installed a lot of cams in different machines. I really don’t want to buy one/install to find out that it won’t work. Im a bit confused on how a lower cam lobe will allow the lever to work?

TexFest
09-27-2018, 01:09 PM
the xr200 valve cover also has a decompression, try that maybe, they look pretty cheap on ebay

bigmike8791
09-27-2018, 04:20 PM
Ill check into that. Anybody with more info on xr setup let me know thx

bigmike8791
09-27-2018, 09:26 PM
I just ordered a 200e cam with matching valve cover. Will keep you guys undated!

bigmike8791
09-29-2018, 09:11 PM
Hey guys quick question. When I go to do the install with the 200e cam/cover at what position should I move the release lever to? 12 o’clock/2 o’clock ect? I did install the other release style valve cover that I ordered with the 200x cam and it doesn’t seem to work. But I don’t know how far to move the lever back? I tried all positions to feel no compression release. If I move the lever to 9-10 o’clock I feel resistance. I don’t want to cause any damage. I had to bend the lever a little to clear the bigger cooling fins. Should the lever lock into position or do I have to hold it there while I kick start it? I’ve been searching the web awhile to not find much info on how it actually works. Someone with a atc lever setup or real knowledge please advise ! I’m still confused how a lower profile cam (200e) will make the release level work lol

Leevvii
10-04-2018, 10:40 AM
i have an XR200 cam [14101-446-000] to put into my X also, very keen to see how this works out. I also searched for info on how it works, alot of info on other makes but came up blank on the honda style decomp, hopefully someone here knows, fingers crossed. I have an old laproscopic eyepiece around somewhere, i just might be able to get a glimpse of the decomp cam from the inside, but things are pretty tight in there, i'll try when i get it all assembled, just waiting on my jug rebore to be done, then i can reassemble it

bigmike8791
10-13-2018, 06:56 PM
Sounds good. The more info the better. I haven’t had time to work on mine. Keep us posted as I’ll do the same

Leevvii
10-27-2018, 10:03 PM
Why special cam? The decompression lever hooks to exhaust rocker. When you move the lever it moves the rocker which presses down on the exhaust valve. Shouldn’t that work?

I agree, in theory , this should work, lets hope it works in place. The 200ES that I removed the rocker cover from, has an exhaust rocker that has a small "tab" on its side, on which the lobe [on the end of the decomp shaft] contacts the valve tab , pressing the exhaust rocker down. The spring must determine the how long it stays engaged.
The 200X exhaust rocker has no side tab. The 200ES exhaust rocker is no longer available from what i can see.

swampthang
10-28-2018, 06:27 PM
The back side of the cam lobes I believe are machined smaller on the 200x and most performance cams so the lever won’t open the exhaust valve .
Go ahead and give it a try , maybe I’m wrong lol .
I’ve installed a lot of performance cams in the 185/200 series motors and it always caused the compression release to not function anymore .


Does anyone have a stock 185/200 cam to measure the backside of the lobes compared to a 200x and 200xr cam? Would like to know too as to this working. I see the part number for intake rocker arms is the same for 185 200 200x xr 200. The exhaust rocker with decompression tab is different on the xr and 185/200. Shortline may be on to something with smaller cam diameter but if thats true wouldnt the intake rockers need to be different as well? Could it be as simple as using xr exhaust rocker with 185/200 valve cover? I know the design of the decomp actuator is different when used with a cable not sure if the eccentric lobe on the end of the lever style will still work on the xr exhaust rocker.

mollie8000
10-28-2018, 07:47 PM
crf 230 electric start plus power

Leevvii
11-10-2018, 09:42 AM
Where im at on this on my 84 200X

THE 200es rocker cover with decompression fits the X motor, and the lobe on the decomp, appears to touch exhaust valve when in the "on" position. The lever appears to “cock” and has resistance, and stays cocked in position prior to kicking. Also, the lever “lets go” when the engine is kicked, so it seems to function as expected. I have not fired the engine as yet, this was just to check the engine was not binding after reassembly, and a quick check of the decomp, not a thorough test.

Some things ive noticed:- the decomp lever does not always engage when it is lifted upwards to the “start” position, it seems to depend on where in its cycle the engine is, and only engages “near” TDC,

Also, the decomp lever seems to “let go” very easily, though this would be expected, to a degree, as the 200ES is a pull start, a lot gentler on the release spring than the sudden jerk of a kickstarter on the X.

swampthang
11-11-2018, 10:12 AM
^What cam do you have in it now?^

Leevvii
11-12-2018, 08:04 AM
XR 200, 14101-446-000 new, with matching sleeve bearing, i used the inlet valve rocker from my 200X, and the exhaust rocker from the 200ES, im wondering if the ES rocker will take the punishment of the X engine, it should, ...in theory, .....but......, im just overthinking it. Just havent had much time to work on it, ill keep you posted.

swampthang
11-12-2018, 09:23 AM
XR 200, 14101-446-000 new, with matching sleeve bearing, i used the inlet valve rocker from my 200X, and the exhaust rocker from the 200ES, im wondering if the ES rocker will take the punishment of the X engine, it should, ...in theory, .....but......, im just overthinking it. Just havent had much time to work on it, ill keep you posted.

Cool. Can you feel any difference? Wonder if the Xr200 exhaust rocker would help any.

bigmike8791
03-09-2019, 09:22 PM
Sorry been away for awhile. Decompression cover with stock 200x cam proved unsuccessful as shortline predicted. I bought another decompression cover with matching cam to try. Won’t be for awhile. Any updates on others trying this mod? Rather not waste any more time lol �� Leevvii how you making out?

Scootertrash
03-10-2019, 02:24 PM
That was my next question. Has anyone installed a xr200 cam in 200 and still had the decompression leval work? I’m hoping townline chimes in as he has installed a lot of cams in different machines. I really don’t want to buy one/install to find out that it won’t work. Im a bit confused on how a lower cam lobe will allow the lever to work?

I did, 84 200S still using the factory decomp cable assembly. I bought a valve cover to eliminate the cable set up since parts are becoming scarce. Never did get around to installing that, although I have a buddy with a 185 who just flips the lever up on his since the cable is gone. Seems to work fine that way, just not as pretty as the dedicated lever.

christph
03-10-2019, 11:58 PM
Why? Because it doesn't need it.