Carb question

[250rcrzy]

I have a 83 atc 110. I got it started the other day, It runs great on the bottom end. The only way I can get it to run on the top is by having the choke all the way on. I have gone threw the carb and set everything were the book said it should be. The timing is set. Good compression everything its a brand new motor. Does anyone have any idea what I can do next.

[MustangChris]

Is it getting enough fuel on the top end?

[250rcrzy]

I dont know why it wouldn't be. i have good flow out of the tank. The carb is clean, no blockages. The slide is pulling all the way up

[200xer]

does it have spark?

That means the engine is not getting fuel on the top end. When you place it into choke mode, it gives the engine more fuel.

Is the float set correctly, it may be sticking too? Have you ever had the bike running right?

[250rcrzy]

on the 86 there is no adjustment on the float. it is a plastic float.

Remove the slide; check what position of the clip is at on the needle. Then drop the carb bowl to see if it's all varnished up. If it is, clean the carb with wooden, plastic or if you good blunt steel picks, you don’t want to scratch up the carb. Punch out all orifices with strong wire if you don’t have needle files. Use compressed air to clean out the orifices and bowl. Then install a rebuild kit, needles, seats, jets, etc. Check the setting on the float last.

They do have an adjustment on the 86, it's the tang located on the high speed needle jet, just like no most carbs.

That should say "just like on most carbs".

This link might help you some:
http://www.ducatimeccanica.com/float_levels.html

Set it parallel if you don't have the OEM setting. A higher float will run rich/fat and a lower setting will lean it out. What elevation are you at? That makes a big differance too, as to what position the needle clip should be at, as well as what size main jet to run.

[250rcrzy]

our elevation 1580, the needle clip is set in the middle location just like the book sais. The guy who used to own this trike said the carb has never been touched. why would it not want to run at stock settings when it did before. All of the pashages are free of debree, I blew threw them with an aircompressor. Everything looks good. still wont run top end. Also the only place to adjust the float is with the tab that touchs the float jet correct. It is made out of plastic how do you bend that to adjust.

If that's the case, are the floats attached to metal holders? Is the float completely plastic.

Sometimes the float holders are the place to do the adjustment. If that's how the float is set-up, you'll need to use the measuring method, normally measured in CM.

If the guy lived at the same elevation, the settings should be the same. I may be sending you the wrong way.

If he lived at a lower elevation, set the needle clip one slot up, and run one size down on the main jet. The porblem is that the engine is running to fat/rich on the top, I can tell by the way you have to run the choke.

[tony_250r]

I meant to say If I where in your carb problem, I would keep the clip in the same position and change the main jet one size higher. Sorry for the confusion but I was trying to repyl while at work, hehehehe.

[85200xer]

try to get one or two size larger main jet. If you have to run it on choke that means it's not getting enough fuel, where is your needle clip, on stock engines its usually in the center ring for the clip if its above the center ring its too lean. I would try a larger main jet if it were me because the main jet controlls from 3/4 to full throttle operation. (go to powroll.com and look under tech tips then under jetting 101) hope I've helped out any ;)

[BamBam]

First of all, the main jet comes on at 1/4 throttle...or at least starts to come on. 2nd, the float shouldn't be used to lean or richen the bike. You should only mess with the jets. The float should be set to come on when the bowl is out of fuel and turn off when it's full. It is true that if the floats are stuck or not adjusted right, the bike will run lean. So make sure they move freely and the tang is bent right.

The choke opens up another path for more fuel to get it. So your main jet is probably too small. First, check you're air filter to make sure it's clean. Then warm the bike up, get on it and do a third gear throttle chop...go full throttle, pull in the clutch, let off the gas and turn off the bike all at once. Look at the plug. If it's REALLY WHITE, you're too lean. If it's Really WET, you're too rich. It should be a nice cocoa brown to greyish brown. Also, another thing that can cause a bike to run lean is a blockage in the fuel line or fuel petcock. Check that fuel flows freely there.

[250rcrzy]

I have done all of that except check the plug. The fuel is flowing good. On this particular bike there is no tang to adjust. the float is 100% plastic. The air cleaner is not dirty it is brand new. I know that there is no blockages in any of the jets they are all brand new stock jets. I am lost dont know were else to look.

[BamBam]

is it running hot?

[250rcrzy]

No I cant get it to run top end first thing when I start it

[BamBam]

No I cant get it to run top end first thing when I start it but does it run top end after ir warms up?

[250rcrzy]

No

[tony_250r]

Sub Quote By: 250rcrzy
The only way I can get it to run on the top is by having the choke all the way on.

This is a good sign that you need to run a larger main jet, try one size up.

Yup, because, in a 4 stroke running rich will actually make your bike run really hot. Can even make the pipe run red.