Jet Size on 200x

[jdparsons1]

I just added a new exhaust (DG Krome Power silencer and headpipe) and I have had a few of you tell me to go to a bigger main jet. I took my carb apart today and pulled out the jet and it is a 108. What size should I go to? Im not real sure what size the carb is, i see alot of talk about 38mm carbs and such but i couldn't find anything to do with mm on it.

[BLAZERONE22]

Run a 110 or a 112 see how that works for you. their like 2 bucks apiece grab a couple and start high and work your way down.

[slippy4]

108 worked fine for me, tried 110 and just kept flooding out

[jdparsons1]

Mine used to flood out easy w/ the 108 when I had my stock exhaust. I know the guy who owned it before me put a brand new carb on... Does the size of the carb make a difference.

[ejc042]

I have the exact same pipe and I still run the stock 108 jet. I do not have any problems with it at all.

[ATCMedic]

Let me jump in here with some info on carbs. Your engine is basically just an air pump, the carb is designed to provide all of the air required to burn the fuel it is designed to take in. Unless you really modify your engine to take in a LOT more air than stock you shouldn't need to change your carb. It is true that anything you do to increase airflow (i.e. your new exhaust) will require a carb adjustment, or in the case of a big jump in airflow a new main jet. You can most likely get away with your stock 108 with the new pipe, but you will need to richen the mixture on your slide needle (move the clip) I learned this the hard way on my first aftermarket pipe install on an '83 250r that this was necessary as I burned a hole in the piston my first day out. :oops:

[jdparsons1]

Hmm... I started off leaving the clip at the middle setting and when I switched to the new exhaust I noticed a backfire so I lowered it on notch. Maybe I should lower all the way and see how it runs. Or maybe I could go with the 110 jet and set the clip in the middle again. My friend said its a good idea to start high and run a little rich and adjust lean from there.

[ATCMedic]

your freind is right, leaner runs hotter which damages your engine. I would move the clip one notch at a time until it stops backfiring (or "lean popping" as I call it) if you can't get it to stop backfiring and run out of slots for the clip, then you need the next size jet in it.

[jdparsons1]

I moved it down one and it doesn't seem to backfire anymore, i may still bump it another just to experiment. How do you tell if its running to rich?

[TimSr]

You need to read your spark plugs, and I caution against using the needle as the first carb adjustment. What you have done is richened it at mid throttle, but when the throttle is wide open, your needle setting effects nothing whatsoever, and if you were lean before, you are still lean now. If you are worried about melting a piston, its a lot more likely to occur on the top side, than at midrange. The main jet shoudl alwasy be dialed in first, and only then do you fine tune the midrange with the needle.

[jdparsons1]

That makes sense. Thanks!!!

[jdparsons1]

Went to the honda shop and they had a 110 and a 115 jet for my carb. I threw the 115 in and it seems to run great. Will watch my plug to see if it is running too rich but it seems to have plenty of power and not pop or backfire at all.

[atc1985]

Hi there,
How many more horses are you getting with the new pipe?
Can you tell the difference?
My 85' 200X still has the stock pipe. :)

[jdparsons1]

I have no idea how many hp im getting w/ the new pipe... I do notice a difference though, when i was riding in 2nd i can usually pop a decent wheelie, well when i hit the gas it almost threw me off the back. :-D

Seems to do alot better mid to top range too

[atc1985]

thanks for the reply...
Wow, that means it is a must to replace the pipe. :)

Thanks again.