questions already-- carb....

[masonryman13]

ok, 1upfront has helped tremendously. my 84 250r is now bored 0.80 over, uni-air filter, no lid on box, dg pipe & silencer, boyseen reeds, stock carb. my jetting is at 115 main and 38 pilot. mixing fuel at 32:1 amsoil. clip on needle is on leanest position(top) and air/fuel screw is at 2 turns out. she still wants to run a little rich and will not idle for long. i dont know how much further to downsize the jets or if i even should. i dont want to burn the piston. anything i'm missing????

[Liquid-Darkness]

What is stock jetting for that bike? Main, pilot and clip setting. What I would do is this:

Jet your idle/pilot jet to stock size. Get the bike to idle. If the idle climbs slowly or idles high, the pilot jet is too big. If the pilot jet is too small, the engine will idle lower and lower and die. The throttle valve should be almost closed with the idle set by the pilot jet and a hair from the throttle stop screw.

Start and warm up your bike. Set your idle with the throttle stop screw, then turn the mix/air screw in 1/4 a turn or out 1/4 a turn until your idle is as high as it can get with out being closed more then 1 turn, but not open more then 3 turns. Then re-adjust your idle with the throttle stop screw.

Your needle should be at a position where you can cruise around while not in your powerband and not have a real bad drummer noise from being too rich. If you ride and hit the power band slowly and its burst of power is short and not real powerfull, you are too lean.

Jet your main 3 or 4 sizes larger then stock. Its a good place to run your engine. Drive around and try it out. If you can't stab your throttle and jump to max power and shift through 1st 2nd and 3d gear, you are probably too rich. This should be about all you need to get that trike running nice.

Also it would help if you ran premium fuel. With a carb thats been rebuilt and blown out with compressed air, jetting just one or two sizes above stock should make it run great, with the above methods applyed. Peetering out and dieing sounds to me like a small or plugged up pilot jet, or it gets too hot and starts to pre-detonate.

[masonryman13]

stock main is 138 and pilot is 50. with these in the trike bogs real bad in 1st and fouls the plug in 15 min. plug chop tests have revealed black and wet plug w/ 138, 135, 120, and 115 is close. idle set screw is all the way in. wont idle though. maybe a little bigger on the pilot?? 42 or so??

[Liquid-Darkness]

Somethings gotta be wrong then. At least stock jetting should be just a bit lean. I dunno, anyone have any ideas?

[Rustytinhorn]

What about the needle valve and needle seat? I would check your float height. Also if the floats are saturated with gas, then it will cause them to not float as well, allowing more gas into the bowl.
Other than that I don't know, I have the same problem on my liquid R, I have to jet it way down for unknown reasons. I am looking for a Colortune, its a spark plug that has a window on it you can use to tune your air/fuel mixture while the engine is running.
Just for the heck of it you could unscrew you idle screw until its not touching the slide anymore, turn the choke off, and set the air screw to "lean" and see if that makes any difference on the main jet for a run or two atleast.
Another thought...is your slide needle stock??

[masonryman13]

i dont know if the slide needle is stock or not. it was in there when i got the trike a couple of mnths. ago. i'm thinking a new carb. b/c the guy i got this from claims he reblt. the carb. and that scares me since i've seen what other things he so-called fixed. it looks like he used a hammer and chisel on the rear bearing carrier to change the bearings. a real top grade mechanic (lol). havent hearde of a colortune. let me know where u find one.....

[Erics350x]

Is the O-ring still on the mixture screw? If not you'll never get it set right. I would set it all back to stock the move up on the main jet size 1 or 2 at a time. You don't have enough mods to be goin up very high on the jetting.

[masonryman13]

up on the main jet?? stock calls for a 138 and i'm down to a 115 to keep it from fouling plugs......??????

[tussin5878]

On my 84 im running stock jets,middle needle position,dg pipe,stock silencer, lid on airbox,uni filter,40:1 amsoil.Both screws are 1 and a 1/2 turns out. It starts and idles very well. Its a little flat,stumbly in 1st and 2nd 1/8 to 1/4 throttle (slightly rich needle?) But 3rd through 5th is right on. hope this helps.

[masonryman13]

well, i would say 3rd - 5th is right on but i only have 4th-- time to re-do tranny. anyways, i think its time to start w/ a new factory carb. i dunno what else to do. i put the stock jets in and it runs like crap and with the drop in jets i'm scared i'll burn the piston?????????? gotta love airfoolers!!!!!!!!!!!

[masonryman13]

ok, update. I changed the carb out for another 84 i got from cert88. It runs GREAT now. I upped the jets back to stock and it idles and runs so smooth. I guess the ports that are internal in the carb were shot and just letting too much fuel pass through, no matter what i did.?? There is now 138 main, 50 pilot, air screw 1 3/4 turns out. I think I will be finding a better carb soon though. Maybe a 36-38mm. This 30mm works great, but I want MORE!!. Thanx for the help guys...