1985 200x jetting questions

[Hedberg_Racing]

Got my 200x running after setting for 5 years. Ive jetted 250r's before, but never 4 strokes. It runs better with the choke on, but still doesn't run very well up high no matter where you put the choke. What jetting should I start with on the old girl? Its got
26mm carb
10.25:1 Piston
webcams 40b cam
supertrapp exhaust
and I moderately ported the head

Im mainly looking for what main size I should put in.
Currently I do not know what size it has in it, I bought the carb from a member and havnt changed the jetting.


What about gearing? Currently it has 18's on the rear and I would like to keep the stock ratio. Would a 13/35 be what im looking for? where is a good place to get sprockets?
Thanks
Will

[ScreaminRed]

Here would be a basis for you to start...http://www.oscarmayer.net/atc/manuals/. Your definitely needing to jet UP! Where exactly, i'm not sure. Could be just main and pilot. Just depends where your power loss is. I would recommend taking your carb apart to see what u have and go from there.

A good place for sprockets is...http://sprocketspecialists.com/, but there are other places too.

[ScreaminRed]

Also, as far as gearing goes...this should help. :)

Sprocket Gearing:

A tooth on the front sprocket either way makes about 3 times the difference than a tooth on the rear sprocket. 12/40 .300, 12/39 .308, 12/38 .316, 13/41 .317, 12/37 .324, 13/40 .325, 13/39 .333, 12/36 .333, 14/41 .341, 13/38 .342, 14/40 .350, 13/37 .351, 14/39 .359, 13/36 .361, 15/41 .366, 14/38 .368, 15/40 .375, 14/37 .378, 15/39 .385, 14/36 .389, 15/38 .395, 15/37 .405, 15/36 .417

When the ratio goes up you go faster by difference in the ratio. Your torque goes down by difference in the ratio Or approximately 2.5% speed and torque change for each rear sprocket tooth change and 7.5% speed and torque change for each front sprocket tooth change.

Going from 20 inch tires to 22 inch tires will make a difference also increasing your top end speed in each gear and reducing your top torque. Your torque will be decreased by about 10% and your speed will be increased by about 10% Or approximately 5% speed and torque change for an inch difference in tire diameter

[Hedberg_Racing]

Read below for updated info

[ScreaminRed]

I'll do my best to help u, as I'm no expert. Pilot jet for idle up to 25% throttle, needle jet 25% to 75% throttle, and then the main for the rest. The jets do overlap each other in terms of throttle response. Is the 110 main factory? If it is, I'm sure you need to rejet the carb completely since you have aftermarket exhaust. This, to me is trial and error, as you'll have to install jets, install carb, and go for a ride. Also, check your service manual to make sure your idle setting is correct. Did you take the carb apart and check the float? I don't, from what your saying, that its "just" the main jet. I would buy from 112-up, so u have something to work with. Don't forget the pilots also.

[yaegerb]

Hey Will, go here: http://www.jetsrus.com/a_jet_kit_atv/honda_200_ATC200X.htm

Get a 118, 115, 112. Start with the 118, needle clip in the middle (DO NOT mess with the needle clip until you get the main operating crisply at wide open). If it bogs, drop a size. Do that until its crisp at wide open. When I rebuilt that carb I put the stock main in it.

[Hedberg_Racing]

okay, thank you for the help. What stumped me on this was it didnt seem to run better with the choke on, making me think it was rich up top, which i couldnt believe it would need to be smaller. But i will get some jets on order, i just wanted to make sure i was ordering in the right direction, larger or smaller. Ive never jetted a 4-stroke before, just 2-stroke 250r's. Which i can pretty much guess without and trial and error at all.

[tri again]

Youse guys are way more evolved than I but if I need to keep the choke on a little or sometimes, for me, it's usually a clogged pilot or slow jet or general dirt craving compressed air under the jets in the internal passages.

I got rid of my last modified trike with fancy exhaust etc because I could'nt stand pulling an sx carb off more than once or twice to do the olympic jet swap event.

[Hedberg_Racing]

Did a lot of dicking with this 3 wheeler today. Finially got a 112, 115, 118, and 120 main jet in, along with a 38 pilot and a 40 pilot.
So I tinkered, threw in the 118 main and went from a drive. Ran much better up top. Plug looked a nice color.
So on to getting the throttle response crisp. It idles PERFECTLY. with a 35 cheapo, non keihin jet in. Air screw set at 2 turns. starts amazing, idles back quick, no back fire on deceleration.
But im still getting this dam bog if I crack the throttle open to fast. From dead idle, if I just pin it, in neutral, it will die, you have to baby it to get it to rev. If you quickly crack he throttle to 1/2, it takes off better than wide open, but still not great.
Now I tried moving the clip on the needle everwhere, found it runs best with the clip on the RICHEST setting of the needle, with the clip on the bottom, needle all the way raised.
Now when I crack the throttle to 1/2, it does pretty good, still not perfect, but 10000000 times better than its ever been for me.
However it still bogs if I crack it wide open from idle. It doesn't backfire when you crack it open, you just get the suction sound from the carb and it dies.
Im about lost on ideas. What do you guys think?
BTW: its 1400 feet elevation, bout 60 degrees outside.

One more thing to add. The throttle response is awesome, if I run the choke half closed... But it has NO power up top with half choke(which I would expect)

[Hedberg_Racing]

bump bump bump

[Hedberg_Racing]

bump! Someone please help! haha
Recently re sealed an oil leak on the stator cover hoping to fix problem and nothing seems to have changed.

[ScreaminRed]

Well, I think your close! Hopefully , you have an air filter installed. From what you said about the needle and the 118 main settings...Here's what I would do. Put the needle back to center and go down to 115 on the main. If your pilot is fine and idling, and takeoff is good at slow speed, leave it alone. That main and needle setting very well could be your bog condition. As I said before, I'm no expert, just trying to help out. :)

[DohcBikes]

Your pilot jet is probably lean

[DohcBikes]

with a 35 cheapo, throttle response is awesome, if I run the choke half closed...t it has NO power up top with half choke(which I would expect)
Actually, reading again, I'm sure it is. You need at least the 38 in there. With a 26 mm carb, it might need to go bigger to compensate for the increase in air.

Once you get the 38 or 40 in there you will likely need to move the clip again and retune the fuel screw.

[yaegerb]

Did you try the 40 pilot yet? Also have you checked for air leaks around the carb and manifold by spraying carb cleaner around the area while its running?

[DohcBikes]

I'm with Yaeger on using the 40. Not sure what elevation you are at but I just jetted a 10.25engine with a 26 on it, and if you are at 118-120 on the main, the 35 is quite a bit too small.

[Hedberg_Racing]

Okay, going to try the 38 and 40 pilot. The reason I didn't think the pilot needed to be bigger was the air screw setting. If your looking to get it at 1 1/2 turns, and im having to turn it 2 turns to get it to idle the best, I figured that meant the pilot was actuall a little on the fat side. But Im going to pull the carb, put in the 40 pilot, needle on middle clip, and the 120 jet and test run it again.
Ill be in toutch shortly!
Thanks guys!!

[yaegerb]

If its running well at WOT with a 118 I would leave it alone.

[Hedberg_Racing]

Installed 40 pilot, air screw 2 turns. needle on the middle clip, and a 120 main.

After doing this, it seemed to run about the same as it usually did. I changed the needle to the next richest spot from centered, 4th clip I believe? Left the rest of the jets the same. And it still has the sputter from idle to wide open throttle, its slightly better it wont kill the machine now when you snap it from idle to wide open. But its still not in anyway perfect. And when I run the choke half way closed, it runs great but I can tell there is a bigger pilot in, as it doesn't idle as smooth as it used to with the choke half closed. Any more ideas? Should I try the needle on the richest setting again??

I did check for intake air leaks, found none, ive checked the valves 3 times now within 1 hour of ride time, clean, actually brand new air filter, air box lid removed, cleaned baffles in exhaust, new spark plug with STRONG spark, Fresh fuel out of the pump 3 days ago, spotless fuel tank, ive cleaned the carburetor every time ive removed it to jet.

I wouldn't think she would be this picky!! haha

[yaegerb]

Are you running the airbox with lid on?

[DohcBikes]

When tuning anything, there a real simple rule. ONE thing at a time, if it gets closer to what you want, do more of it, if it gets worse, go the other way.

Although you may still be lean with that setup, I'm starting to wonder if the carb is too big for your application... this would jive with the fact that it runs good on half choke in the low range.

Got any smaller carbs you can try out?

If you are out of pilot jet options, you could always take the 35 and drill it out to "a little bigger than a 40" lol but you gotta have some tiny bits and be willing to waste the jet if you go too far.

[Hedberg_Racing]

Okay. After installing a 40 pilot, needle on the 4th clip, and a 120 main jet. AND waiting a week for it to warm up before I took it for a spin, I found out this weekend that it actually runs MUCH better after these changes. Almost no bog under load from idle to wide open. Every once in a while, when I am pinned, with the rpm's low, and I let off to say 1/2 throttle, it bogs for a split second then takes off again. The plug is a pretty good color, not black, but quite that lighter tan. I have a feeling its juuuuuuust ever so slightly rich maybe on the main. But after taking it for a spin and being tickled to death on the performance of the motor, I found out my stock clutch wasn't enough to hold it. I pulled the clutch cover off, scratched the metals on concrete floor, added an extra steel plate, and that problem was solved. Rode her pretty hard today and couldn't be happier!!! One last question though, if anyone reads this thread, In the complete gasket kit I ordered from ebay, it comes with 3 total full size, what looks to be, case gaskets. I used one for the center, crank/tranny area, and one for the clutch cover. What is the third gasket for? Has anyone else ran into this??

http://www.ebay.com/itm/Honda-ATC-200X-1983-1984-1985-Complete-Gasket-Set-Kit-/400576334836?pt=Motors_ATV_Parts_Accessories&hash=item5d4435cbf4&vxp=mtr

[DohcBikes]

Its good to hear its running better! You might try lowering the needle/raising the clip just one notch to see if the 1/2 throttle bog goes away.
Not sure on the gasket set, have fun though! PM me if you end up needing a clutch....