Rebuilt carb now it's running rough, but good with choke on

[alfredo4585]

I just did a carb rebuild on my 350 raptor because the float bowl gasket was leaking.

I'm 99% positive I replaced everything correctly, but maybe something needs adjustment? I cleaned all the ports with carb cleaner and all the parts are new so it's clean as a whistle.

It's starts perfect and runs great with the choke on, but then when I don't choke it, it runs rough. I have to adjust the idle screw to keep it running and even then the idle jumps +/- 400 rpm. Sometimes it'll even idle itself at 4k rpm. Tried taking it down the road and she popped a lot. I have an idea that it's running lean. Could I need to adjust my float level? I think I left it kinda high(about 15mm).

Oh, and it's stock, and it was about 60F today.

 

[elwood]

when you took your carb off your intake boot might have ripped. that would cause all your problems. You can spray the boot with starting fluid, if it changes how the thing is running at all it's cracked and needs replaced

 

[alfredo4585]

when you took your carb off your intake boot might have ripped. that would cause all your problems. You can spray the boot with starting fluid, if it changes how the thing is running at all it's cracked and needs replaced

The intake boot checks out a-ok.

My big question is....can incorrectly adjusted floats cause it to only want to run when the choke is on? Because last time I left the floats too low and gas leaked out of the overflow....this time I think I overcompensated and left them too high. I was a little skeptical when I was putting it back together that the level was gonna be an issue.

 

[DeadLastRacing]

Yeas, float level will effect the carb performance. The corect level to set the float is in the manual. I had to do it once on my stock carb. Easy stuff, but it has to be just right. Such a small tab but a slight difference in the level, can really effect its performance.

 

[alfredo4585]

Yeas, float level will effect the carb performance. The corect level to set the float is in the manual. I had to do it once on my stock carb. Easy stuff, but it has to be just right. Such a small tab but a slight difference in the level, can really effect its performance.

Thanks. I'm gonna tweak it later today and try the clear tube method I saw here.
http://www.raptorforum.com/forums/showthread.php?t=538

Also, in that post it says to run the pilot jets 3 turns out. Do jets need to be completely seated, or adjusted in that fashion?

 

[DeadLastRacing]

On our carbs, yes the jets need to be completely seated.

 

[alfredo4585]

Update: Adjusted my float level, I know it's good. Got the quad to run with the choke off, but it takes 5 turns out of the pilot/fuel screw. What is that saying?

 

[duneracerweston]

Its running way lean did you replace the throttle needle? And if you did dose it have multiple settings? If so I would ajust it down a notch or 2 and I would check and see if the main jets and pilot jets are the same size as before

 

[alfredo4585]

Its running way lean did you replace the throttle needle? And if you did dose it have multiple settings? If so I would ajust it down a notch or 2 and I would check and see if the main jets and pilot jets are the same size as before

I did replace the needle, but it only has 1 setting. It has 3 washers on it though. Maybe adding or removing them adjusts it. It's just weird because It was running fine before the rebuild and I replaced everything exactly the way it was. The jets are the same size and I didn't even touch the pilot screw when it started running crummy. Maybe I need to just get a 25 pilot jet up from 22.5?

 

[elwood]

i think something is dirty in there. If it ran fine before you rebuilt your carb, you did add any preformance parts or mod anything. Then the same jets should work fine. Maybe clean the carb again and put your old jets and needle back in and see what happens

 

[elwood]

Also I'm not sure about the raptor carbs but the warrior carbs have a air/fuel screw. That might need adjustment

 

[alfredo4585]

i think something is dirty in there. If it ran fine before you rebuilt your carb, you did add any preformance parts or mod anything. Then the same jets should work fine. Maybe clean the carb again and put your old jets and needle back in and see what happens

Yea it ran fine before the rebuild, it just leaked a little gas from the float bowl gasket.

No mods, just everything that came with the kit. I'll take your advice and re-do everything tomorrow. I have plenty of time finally to go slow and methodical and I'll clean out everything really well.

 

[alfredo4585]

Okay, good news. I had her running with the choke off with 5 to 6 turns out of the pilot screw. She was lacking some power and at 6 turns out, I saw that everyone suggests you up your pilot jet a size. So I put in the old pilot jet and voila, back to her old self again...and with nice juice. Idles fine with some idle screw adjusting, only problem now is that when I give it gas, she stays at a high rpm for a bit or until I adjust the idle screw. I guess I'll just soak the old jets and put them back in, they weren't even clogged or in that bad of shape. I really only bought the kit for the gaskets =)

You had the right idea Elwood, telling me to throw in the old jets. Thanks!

And thanks to everyone for offering your input. I greatly appreciate it!!

 

[elwood]

np, glad to here she's up and running again:atv: