running rich smaller main jet?

[curtis slawson]

hey just put on a DG exhaust on my 85 200x.

wont run without choke on plug is really black should i down size the main jet. It has a 108 main in it atm iv tryed to raise the c clip to the 4th grove witch is lean and tryed adujst the air fuel mixture with no change to the plug still black.

run and idles good on choke but soon has you put to no choke it dies unless your driving then put to no choke and run rough & spurtter dosen`t back fire at all.

And isnt when you put a aftermarket exhaust on it should make it leaner and not make it run rich

so should i change the main jet and get something smaller.

[4x4van]

If it was running good before the pipe, and now it will only run with the choke on, then it is now running too lean (the choke is richening it up). Smaller main jet will will make it even worse. A plug check can't really be done without a good clean WOT plug chop, and it sounds as if it won't run good enough to do that accurately.

Again, the key here is that it runs good with the choke on. The choke richens it up significantly. So that's what you need to do with the jetting; richen it up.

[curtis slawson]

the bike was running a little lean befor the pipe swap and now the plug is pitch black. iv also tryed 110 main jet with no inprovment stock jet is 1.08.

if i drive with the choke on then shut it off& it runs but spuddders when wot and feel`s like there no power but still dont idle unless i say on the gas with no choke

the plug was light tan befor the swap now it carboned up not wet but dry black plug

i tryed to plug shop it came out carbon black plug Brand new plug and still havent heard a back fire on let of of gas

the bike ran great with stock pipe could lift it up in 4th gear

also dosnt have stock pistion has a wiseco high compressin 10.25.1

[4x4van]

I'm telling you, it's too lean. One size larger main is likely not enough. Think about it; what does the choke do? It richens it up. If it will only keep running with the choke on, then that means it is running too lean. Sputters on the top end, no power at the top, will only run with the choke...it's too lean. In the jetted condition that it's in, you can't do an accurate plug chop.

[curtis slawson]

ok so get bigger jet then a 110 main jet & lower the c clip niddle so it more rich too and adjust fuel mixture too

[oscarmayer]

you said you never touched the carb at all before the pipe change???
wis the pipe you ggot new or used? if it's used, the piep could be partly plugged causing backfeed.

[curtis slawson]

it is a used pipe

[Scootertrash]

Curtis,
First, lets try to keep it to one thread to keep the confusion down. It's also easier to track your progress.

Go here http://www.3wheelerworld.com/showthr...Jetting-Theory

and print out the instructions for jetting and take them out to your garage with you when you do this. It will help you learn the procedure and the results from each change you make to the system.

Is the air filter clean? When was the last time the carb was cleaned thoroughly? You may need to take the bolt out of the muffler and remove the baffle to be sure it's clean.

You need the machine to idle without the choke first before you can continue. Make sure your idle jet is clean, don't assume that it is, verify that it is. Set your pilot screw to the factory setting ('83 - 1 3/4. After '83 - 2 1/4.) Leave the 110 main jet in and set the needle to the middle groove. Put the slide back in and tighten the cover. Make sure your throttle cable is adjusted properly. Put the airbox cover back on. Start it and warm it up to operating temp in your driveway. Once it's warmed up see if you can get it to idle without the choke by using the idle speed screw on the side of the carb. If you can get it to idle then you can fine tune your pilot screw before you test ride.

Take it for a test ride and see how it runs, then follow the jetting instructions in the link above or post back here. I'm laid off and around generally most of the day, I'll check in to see if you need help.

Jetting can be frustrating. Be patient you must young Jedi!!

[curtis slawson]

Ok thanks for the info i will try this tomrrow.I have cleaned the carb befor i put the new exhaust on air filter had just been cleaned

Curtis,
First, lets try to keep it to one thread to keep the confusion down. It's also easier to track your progress.

Go here http://www.3wheelerworld.com/showthr...Jetting-Theory

and print out the instructions for jetting and take them out to your garage with you when you do this. It will help you learn the procedure and the results from each change you make to the system.

Is the air filter clean? When was the last time the carb was cleaned thoroughly? You may need to take the bolt out of the muffler and remove the baffle to be sure it's clean.

You need the machine to idle without the choke first before you can continue. Make sure your idle jet is clean, don't assume that it is, verify that it is. Set your pilot screw to the factory setting ('83 - 1 3/4. After '83 - 2 1/4.) Leave the 110 main jet in and set the needle to the middle groove. Put the slide back in and tighten the cover. Make sure your throttle cable is adjusted properly. Put the airbox cover back on. Start it and warm it up to operating temp in your driveway. Once it's warmed up see if you can get it to idle without the choke by using the idle speed screw on the side of the carb. If you can get it to idle then you can fine tune your pilot screw before you test ride.

Take it for a test ride and see how it runs, then follow the jetting instructions in the link above or post back here. I'm laid off and around generally most of the day, I'll check in to see if you need help.

Jetting can be frustrating. Be patient you must young Jedi!!

[El Camexican]

For what its worth I've never seen where putting a different pipe on a decent running engine made a dramatic change the way it sounds like yours has. Being off one jet size, or needle clip height (which is usualy the most a pipe change will require) does not effect an engine the way yours seems to have been. I'll add that most stock jetting is a little rich, so a pipe often makes things run better with no added tuning. I suspect you will find something else causing this when you look close.

[4x4van]

Aahhh...you never siad it was a "used" pipe. In fact, in you rother post, you said you got a new DG exhaust (must have meant "new to you", right?)

As Oscarmayer said, the pipe/silencer could be partly clogged up. Scootertrash has some very good info/instructions...follow them and you should be able to zero in on the problem.

El Camexican; a "good' pipe/silencer combo can easily cause a 2-jet size difference with a high performance 2-stroke, which is what I am more familiar with. But may be right in this case, considering that his bike is a 4-stroke.

[Scootertrash]

When I put the DG on my 200S I went from a 95 main to a 100 main and my needle ended up one groove higher.

[curtis slawson]

hey just tryed everything still dont idle with no choke should i lower the c clip one more ? cant get it to idle with no choke unless i stay on the gas & try to adjust idle screw just make when i start on choke it rev real high

[rdlsz24]

Make sure your pilot jet is not clogged. That's the first thing I check when I can't get something to idle right. Never fails that sucker is plugged.

Rob

[curtis slawson]

ye its not clogged i can see right therw it

Make sure your pilot jet is not clogged. That's the first thing I check when I can't get something to idle right. Never fails that sucker is plugged.

Rob