Thanks, I'll try your suggestions tomorrow after work. I ran out of light tonite and don't feel like pushing it into the garage.

Here's my old thread from last year about this for all the things I've tried:
http://forums.atvconnection.com/mess...ighlight_key=y

 

I'm going to give a shot at this.

When it is cold do you have to use the choke to start it? If you don't this means a rich condition on the idle circuit. I don't have my manual with me but you can adjust the idle air mixture on the carb I think it may be 1.5-2 turn out (dont quote me).

Or do you have to use the choke for long periods of time? Longer than 1-2 minutes? This is a lean condition and you can adjust the idle air mixture screw same as above. This may also be a pinched hose (I had this problem and rejetted and found a kinked hose, not sure which one fixed it though).

When it is warm does it idle with no choke? Idle circuit is ok and air mixture is ok.

From my understanding the Idle circuit only handles the idle. If it runs good there probably isn't anything wrong with it.

The needle controls the fuel from idle to just about full throttle. (again I don't have my manual but is the clip in the corect groove?) This will effect the throttle response of the mid range. To rich or to lean depending on throttle position.

The only time it runs truely on the main jet is at WOT. The needle is pulled up. This is why you perform WOT tuning on these machines and can check the plug for rich and lean conditions.

You may also want to check the float level. If the float level is wrong the idle circuit will still work fine but the rest of the throttle range could be at a lean condition. Since this carb has been off a few times I would recheck this.

Then there is the usualy suspects. Water in the fuel. Fuel old. Clogged filler vent. Clogged fuel valve. (This may explain why it worked on prime) Bad plug. Loose plug connection.

I think you may have checkad all this at one point but it may be time to start over. Check all the vent tubes. Pull the fuel valve and clean. Change the plug. ect..

Start from the top of the tank and work your way through the whole fuel circuit. Replace, clean, and adjust everything.

 

Before all the trouble (with the 115 jet), I had to choke it about 1/2-3/4 to get it started, then about 30 seconds afterward, turn choke off. With the 120, it fired right up without any choke (hadn't been started in 2 months). Oh and that was after I drained all the gas out of the tank and carb bowl and added brand new fresh stuff. Also, I read other places about adjusting the idle/air mix. I tried that on tuesday night, 1.5-2 turns out and the thing idled so high it would grind putting it into gear and then die because all it wants to do is idle. I kept turning it out about 6 times till it was at what it usually idles at before it gets lopy.

No, never had to choke it that long to make it idle. After I started having the problems and before i swapped the 115 for the 120, i had to have the choke on about 1/4-1/3 so it would rev and move.

Yeah, I don't think anything is wrong with that because it idles just fine.

I wouldn't think anything would be wrong with this because it ran great on Monday when I put the tank on Prime and drove it around. Stopped and restarted it a number of times. Figured I had narrowed it down to the tank valve selector. Tuesday morning, I had this worry that maybe with the tank valve left on Prime, the valve in the carb might leak filling the carb throat and engine cylinder with gas so I turned it back to "ON" before I went to work. Then Tuesday nite, all it'll do is idle again and nothing else.

Yeah, that sounds right, because I was never able to run it WOT so the plug was blacker than normal because it was idling richer with the 120. I bet it would have looked normal if I could have raced it then immediately checked the plug.

This is one of the things I'm leaning towards as well after taking some time off to think about it. I just wanna still blame that damn tank valve tho.

Fuel is brand new. Filler vent is clear. I put 1.5 gal of gas in on Monday, so I'll drain that tonite when I pull the tank and check the tank valve for trash. Plug? as in spark plug? It was just replaced and it ran fine on Monday so I think I can eliminate it as the cause unless it's the coil causing the problem. Spark plug wire grips tight at both ends.

I'll give it a shot like you laid out. Thank you for your help.

 

I am leaning toward the tank valve too. If there is junk in it (we all know that there is junk in the Suzukis tanks) it could stop the fuel flow in the on position (or reduce it). When you turned it to prime I think that may be a different fuel circuit (this let it run good for that day). It to may have become plugged up with the junk from the tank. Since you have an inline filter, I would hope that the filter would stop this junk from going to the carb.

That fuel petcock is a pile (IMO). I actually leave mine on prime and have a inline fuel shut off after the inline filter. In theory the float valve should stop the fuel from flowing into the bowl (it has on mine so far). I haven't had any problems with leaving mine in the prime mode. I turn of the inline petcock off when it is going to sit for a few weeks or when I transport it.

I don't know why Suzuki had to reinvent the "wheel" with this petcock. The only reason I can figure that they use this style is when the quads are transported, people forgot to turn the fuel off. This may have kept the stupid people safe but it sure does mess the rest of us up.


Good luck

 

Just came in from the garage, so pardon my rambling I'm partial high on fumes.

Checked the air filter, no tears or anything, not hardly dirty. Looked it over really good.

Took the tank off and pulled the fuel valve. both screens on the little straw things that stick up where nearly spotless. The screen's mesh are so damn tiny I don't see how any trash could get from the tank to the carb unless it's ultra fine dust. They're tall enough too that you'd have to have a leave of something wrap around it to cut off the fuel flow. Now I see why they probably don't put a filter on in the line, I wouldn't think it would be needed. The service manual says nothing about taking the actual valve apart, so I didn't. Above, Redking2101 said it isn't rebuildable anyway. One thing I noticed was when I would suck on the vacuum hose that runs to the valve, I could hear it click and it would release gas for like a second, then no more gas. ??? Maybe it needs more suction than I have. Blew thru the fuel line into the tank, that seemed clear when on Prime. Couldn't on Reserve or ON, probably by design. Can't tell if Prime pulls from the Reserve straw or the On straw.

So next I pulled the carb off. Dismantled everything except I didn't drill out the plug above the pilot jet. Pulled the main jet and needle holder. Put the 115 main jet back in. Also pulled the slow jet and starter jet. All were spotless. Checked the diaphram and needle, it was straight and no tears in the diaphram... was a PITA to get the entire thing back in the groove and put the top cap back on. Checked the operation of the floats and the needle valve. Everything seemed to work fine, everything looked brand new... hey it should, it's a 2005!

Put the carb back on and checked and rechecked every vacuum line, routed them so that there was absolutely no kinks.

Figured I'd check the valve clearances again (I checked them at 100 miles and found the exhaust needed to be tightened up about .07 mm to get it within spec). Put the engine at TDC and found the exhaust was about .22mm (max tightness, so maybe it's tighted up a bit), Intake was about .10mm (max looseness) according to the service manual, but within specs so should be fine there.

Put the top motor mount back on and such , slipped the tank on and hooked up the vacuum line to that valve and the fuel line. Hit the starter button and she turned over... didn't have to pull the hand brake to attempt to start it?? (need to read about that circuit and find out why). Tank valve is at the ON position. Left the drain screw on the bottom of the bowl open and after it turned over a few times gas started running out. Had to choke it about 1/4 (garage was about 55F), and it fired up. Let it idle for about a minute, then turned choke off. Barely touched throttle and it sounded lean and then back fired. Let off and let it idle some more. Turned tank to Prime. If i very slowly pressed the throttle I could get it to eventually rev up but it was missing like a muthertrucker. Had the wild idea to blow thru the vent hose on the fuel filler cap (you know because I'm getting so friggin good at blowing and sucking on this thing) and maybe i was imagining things but the throttle response might have improved but it still ran like crap. After about 10-15 minutes of idling it and trying different things it started to run a little better, but would still pop and miss when i would try to push the throttle at a medium pace (not punching it but not driving Miss Daisy either).

Oh, I also tried a different fuel filter, I picked up a Doetch or something like that at autozone on the way home. No difference when I put that on.

I'm still going back to that valve, maybe on prime now it still isn't flowing enough. Or maybe it's the ignition box, or an adjustment on the carb i'm not qualified enough to fix. Or maybe the valve clearances aren't correct?

If I take it back to a dealer around here, they'll probably just give me the same bull that it's just cold blooded and it needs to warm up for 10 minutes because after they mess around with it for a while, it starts to run a little better (then they blame the popping and missing on it being jetted too lean. I've ridden it in 20F weather at my house, it fired right up, was ready to go in a couple minutes and it ran good. I want it back to the way it was. Any other ideas?

 

BTW, here are the troubleshooting steps in the back of the Service Manual:

Engine stalls easily.
1. Fouled spark plug
2. Defective generator
3. Defective CDI unit
4. Clogged or defective fuel valve
5. Clogged carburator jet
6. Valve clearance out of adjustment

 

My turn!!! First off, I'm not saying that anyone that has posted is wrong, as there have some very good thoughts.

Here's mine: With the 115 jet and 1/4 throttle it runs "decent". That suggests that it is lean in the main jet circuit. Before you go to the next size up jet, you should first try adjusting the needle clip. As you raise the needle (by lowering the clip), you are raising a tappered needle higher out of the hole of the main jet (in reference to the position of the slide that the needle is installed in). If the needle is raised to it's highest adjustment and it is still lean, then you need to go to the next size larger jet. With the 115 and the needle fully raised, that should be "approximately" equilivant to the 120 with the needle fully lowered. Therefore, if you went from the 115 to the 120 without adjusting the needle, you may have gone from a lean condition to a rich condition.

BTW, except in extreme conditions, the main jet size has nothing to do with the idle. Going to the 120 would not cause a richer idle mixture.

 

In my stock 2004 Eiger CVK34 carb, the needle is fixed; ie. no adjustment possible.

Same with the 2004 Vinson CVK36 carb I bought and installed on my Eiger.

 

Yep, there was no adjustment on the needle, unless they make some type of shim set to place in the bottom of that plastic thing the diaphragm is attached to.

 

try a new plug. i have seen new ones be bad so try that and you should be ready to go!!!