200s poor throttle response

[Big Paul]

I want to first start off by saying how cool this forum is and it is one of the few places that I can still find anything out about these old three wheelers. Anyway, I have an 84 200s that will die if I floor it from idle really fast, but if I dont punch it extremely hard from an idle then it is fine and it runs great and does not smoke. In other words, I just have to be a little slower on the throttle at idle to get the rpms up just a hair and then I can hammer it. The plug is not fouled and when I say it runs good, it runs good. It will pull wheelies in third without a problem and it has a lot of power and also idles great. I know these carbs do not have an accelerator pump, so is this normal for a 200s? Could I upgrade to a 200x carb? Or could it possibly be to retarded of timing?

So far, I have:
Rebuilt carburetor
New coil, spark plug wire, spark plug, CDI, Stator coil
Re-oiled and cleaned UNI air filter
Adjusted valve lash
(no, i did not do all of the above to try to fix problem, I was just doing a tune up)

Thanks alot for any replies

[Buckizbrutal]

Hey great to here how good it runs, I have the same atc. I have the same thing with mine. I did all the same tune up but with new k&n filter and put a dg rcm exhaust on and jetted. Still I can't just fully crack the throttle. I mean it's not like I have to really ease it on. It will take off!!! But yea I have the same deal, hope someone chimes in to say if this is normal or how to help the problem (which isn't really a big prob)

[muthey]

no that is not normal, but it could be anything from a piece of debris in a jet that you have missed to still needing proper jetting, to adjusting valves, or timing as you mentioned, or even a cracked air boot. Have you ever checked the timing chain to see if it is needing to be replaced, there are alot of things that can lead to this, which you'll have to go through them all, until you find the cause.

[Big Paul]

Thanks for the response. I will have to check on those things. Also, could the needle that goes in the top of the carburetor that is hooked to the throttle cable be out of adjustment? The one that has like 5 slots where you can move the C-clip to adjust it? What does that do anyway if the throttle moves the needle a lot in the first place? Does it adjust air/fuel ratio at idle or throughout the whole rpm band?

[Rebel Customs]

Just floor it everywhere... problem solved

[muthey]

standard selection for that needle is to have the circlip in the middle slot. That is your main needle, it controls how much fuel you get when you hit the throttle. There are a few things to check on it, first make sure the circlip is in the right place, second make sure the w clip which keeps it in the throttle body is there or it will move up and down on it's own. And third check for wear, a bent or worn needle will cause plenty of issues for you.

[Buckizbrutal]

My problem was fixed when I upped my pilot to a 40. Great response now!!!

[Big Paul]

Well, I messed with the needle adjustment and the pilot screw adjustment and I could get the response no better. I tried the needle in every single position. The needle is also brand new and is not bent. I also checked for a vacuum leak with starting fluid and it does not have one.

One thing I forgot to mention is that it has a DG header and muffler and a UNI performance air filter. With these mods, airflow in and out of the engine is increased, so should I put bigger jets in the carburetor? If I take the air cleaner lid off from under the seat, the engine gets too much air and runs really rough. Also, with the lid installed and the carb at half choke when warmed up, it will rev up perfect straight from idle. So I think I need bigger jets to supply more fuel.

The question is, where do I buy them? And also, should I increase my main jet size, pilot jet size, both, or what? Thanks

[muthey]

I would definitely get bigger jets, wouldn't hurt to get both pilot and main jets you should be able to get them from a honda dealer, or search the web for an online supplier, you will need to see what your stock size in the carb is and go bigger from there, 1 to 2 sizes bigger. It is always better to be rich than running lean

[WJG1000W]

be for you go by bigger jets adjust the mixture screw in the bottom of the carburetor closest to the engine i was tuning my 200m the other day and it did the same thing i gave it a little richer mixture and now it works great

[Buckizbrutal]

The stock jet sizes for 200s is 100main and 35 pilot. I have a dg rcm full exhaust and a k&n air filter I got a 38 and 40 pilot and a 105 main. After messing around (for a while) and only Changing one at a time and checking my results I ended up with the stock main 40pilot and needle clip 2nd notch from the top. It runs great with great response. You will need to see what works for you but hope this info helps.

[Big Paul]

WJG1000W
be for you go by bigger jets adjust the mixture screw in the bottom of the carburetor closest to the engine i was tuning my 200m the other day and it did the same thing i gave it a little richer mixture and now it works great

Response: I tried adjusting that screw (pilot screw) and it did not help me any. I can actually screw it all the way in and it will still idle and it wont run too much differently it just makes the throttle response a tad bit slower. Is this normal or is my carb worn out? It still has the original keihn carb and the rebuild kit did not come with the very small o-ring for the pilot screw, so I just used the old one which was in OK condition. If I screw the pilot screw all the way in, should it kill the engine because it blocks the flow of fuel or no?


Buckizbrutal
The stock jet sizes for 200s is 100main and 35 pilot. I have a dg rcm full exhaust and a k&n air filter I got a 38 and 40 pilot and a 105 main. After messing around (for a while) and only Changing one at a time and checking my results I ended up with the stock main 40pilot and needle clip 2nd notch from the top. It runs great with great response. You will need to see what works for you but hope this info helps.

Response: thanks alot for the information, im sure it will help me in solving this mystery. Is your threewheeler a 200s too?

[WJG1000W]

mine has a new 20 dollar carburetor off of ebay

[Buckizbrutal]

Yes it is a 84 200s I order my jets from jetsrus.com and they even sell genuine kehin jets, and fast shipping!

[Big Paul]

Cool, will be ordering my jets soon

[Buckizbrutal]

GREAT!!! Hope you get it solved!! The best if luck!

[Big Paul]

Well, I ordered a 38, 40, and a 42 pilot and also a 102 and 105 main jet. After messing around with all of the adjustments for hours, I could not get it right and I dont know how many times I pulled the carburetor off. At one point in time, it had great response from idle but it would run a little rough up high and then would randomly stall when I let off the throttle. So, I decided to check timing.

I hooked up a tach and set idle to 1300 like manual said and checked my timing with an advance timing light that lets you see how far your timing is advanced. My timing was advanced 35 degrees past where it should have been!!! So, I pulled the pulse generator cover to find out that both of my springs on the mechanical advancer were broken. So, I think I finally found my problem!

Now, the question is, where do I buy the springs? I checked bike bandit and also babbitts sport center and they only sell the whole advancer assembly and dont even list the springs seperately. I will buy the whole thing if necessary, but it is expensive. It costs $140. Do any of yall know where to buy the springs and also I heard there is supposed to be rubber pads on the advancer weights and also some peices of padding on the backing plate too that like to wear out, so should I replace the whole thing anyways for insurance?

Thanks for the responses!

[WJG1000W]

just an idea but have you tried dennis kirk

[Big Paul]

I just looked there and they dont sell anything for the advancer unit. But, they did sell some pretty cool stuff

[Big Paul]

I went ahead and ordered a whole brand new advancer unit. Thing is driving me broke!