I just ordered a 130 and 135 jet for my Eiger. I've been looking around and the Yamadog Wolverine comes stock with a 34mm carb and a 145 jet, some people are putting 160 jets in! So, with the Eiger carb 2mm smaller, I figure a 135 should make a huge difference over a 122.

ALSO, when I pulled my carb, I noticed the idle circuit screw (mixture) was only opened 1 1/8 turns, which according to ATV Connection's article on the CVK32, is a FULL TURN too closed. They said that factory setting was supposed to be 2 1/8. SO, I opened it up to what that article said was supposed to be right, and WHAT A DIFF! Definitely a noticeable difference in idle quality, cold running, and off the throttle power. Of course, this doesn't make a difference anywhere else in the power band, but at idle and just off idle it's night and day.

AND ANOTHER THING... when I called the Suzuki Stealership and asked him for a 135 jet for my Eiger, he said "Those Eigers sure do run lean from the factory, don't they?". SO, it's something that is well known to this guy.

I'll be losing some gas milage, but I'll be gaining power. And isn't that what we're all after?

I'll be getting them in this week, so I'll post some 'seat-of-the-pants' results as soon as I get them. This could be the easiest way to get some more juice out of our Eigers!

 

Were you having any symptoms of lean running? Did it sputter or miss? Did you do a plug check to see if it was too lean? You could end up with worse performance, if the bigger jets make it too rich. Engines run their best on the edge of lean, as you get richer, there comes a point where power will drop off. Unless you were thinking of air box mods and new exhaust system, then you could take advantage of the bigger jets.

 

True with 2 strokes, not with 4. A 4 stroke will usually make more power on the rich side of the balance. Argue all you want, it's gonna be hard to convince me that my experience tuning engines was imagined.
Ever set the mixture on your truck using the lean idle drop method? Then you'd know that when you notice the idle speed drop turning in the mixture screw, you then turn the screw back out 1/2 turn. That puts you back into the rich side of mixture.
Also, would you say it's coincidence that the most common method mentioned on ATV Connection forums is to re-jet? If you look at displacement vs carb size (in mm) vs jet size in most single cylinder 4 strokes (we're talking from the factory here) the Eiger is jetted very lean. Mine in particular lacks throttle response (in my opinion), runs poorly cold, and has a lean exhaust smell. A 375cc engine with a 32mm carb should, if you do the math other manufacturers of performance oriented quads use (Warrior, Wolverine, etc...), a 122 jet is about 10% lean. THEN if you read the threads of people that say "I want more performance, what should I do?"?, all the people commenting say "Jet larger a size or two".
Another note I should repeat is that my dealer immediatly mentioned the Eiger's tendency to run lean from the factory. I think that my dealer, unlike some of you other guys who have moron dealers, actually knows what he's talking about. He's a pretty knowledgeable dude. And that couldn't have been just coincidence.
Unless you have a dyno, there's no way to actually measure the horsepower you're running accurately. A little experimenting and some knowledge of basic carb tuning might actually serve me well. We'll just have to see, won't we?
I think your statement ended with "...too rich". That WOULD be a mistake wouldn't it? But it won't be too rich... it's gonna be juuuuust right. And looking at the insulator has never been an accurate diagnostic unless it's WAY too lean or WAY too rich. There are an infinite number of steps between 'white' and 'black' that could be the difference between 'runs decent' and 'hauls ***!'.
I'll let you know how it works out... I'm optimistic.

 

Go read the thread in the Yamaha forum titled "How can you tell if you're running lean "

Seems applicable.

 

Im sorry I replied, have a nice day.

 

Ok

 

I am interested in your results. You adjusted the original jet one turn to run a little more rich. You noticed better performance. You have ordered a larger jet. Now the question about the 3 senarios....
1. Performance of stock setup vs performance of mixture adjustment of stock setup vs performance of new jet.
Curious if new jet is similar to the 'adjusted' stock set up. I'm ready to tinker with the carb, just curious about elevation changes from 5000 to 7500 ft. when riding. Late.

joe.

 

Actually, what they call the 'mixture screw' really only adjusts the idle circuit. The screw adjusts how much fuel bleeds in with the throttle closed. The main jet at the bottom of the air tube is what adjusts mixture when you're on the gas. And, I am very interested to see what happens when I go up into the mountains. I might have to carry my 130 with me to swap out from the 135 I'm gonna run if it's way too rich at altitude. We'll see.

After the 'mixture screw' adjustment, w/o the new jet, it DOES run better cold, less hesitation. Also, I can pull the front tires off the ground easier. That is, the only way I can pull the tires up is in first gear, on asphalt. But before I had to rev the **** out of it while I held down the shifter (from 2nd to 1st) and pop into first. Now I still have to pop into 1st, but I don't have to have many R's to pull the front end up. I believe this is due to there being more fuel at low throttle opening from turning that screw out a turn, thus, my mixture is better for a few moments and provides a little more power off idle.

I'm stoked about getting my new jets. They should be here Friday. I'll post the part #s for you people that may be interested.

 

Be careful with how much you go the other way. i just traded my 03 eiger in because suz still didn't have my carb problems figured out after 6 attempts. It was running to rich and would bog down and lose power.

 

That's kind of crazy. Seems like a simple enough carb to me. Oh well, you must have a real bummer dealer.

ALTHOUGH, the Keihin carb IS really wacky. I mean, vacuum actuated slide choke? And a butterfly for air metering??? Totally bizzaro.

I can always go back to the weeny little 122 if I have probs. It's too bad you had to give up your Eiger, but looks like you traded up!!