STIHL Intellicarb Carburetors

[bwalker]

I used to rejet my sled in 10 degree increments. Made a difference when racing. For trail riding, a swing of 20 degrees on the same jets could be into meltdown territory, or running too fat.

Just like saws most guys are dealing with blubbering rich engines. To them it feels normal. When they do get their hands on something tuned right they rave about throttle response... never understanding that it's suppose to be that way all along.

 

[EFSM]

Happy new year!!

you are free to do with your time what you please. That includes wasting it.

Guilty as charged. I wasted another few minutes this morning testing a saw when it's a little cooler. My results from 2 days ago:
52 * Echo CS-530, WOT 15,360 RPM's, in the cut with a fairly non-aggressive chain being gravity fed 12,600 rpm's
This morning 34* same saw, chain, log, and tank of fuel
WOT 15,700 RPM's, in the cut 12,800 RPM's
I know this is not all-conclusive, and I'm not saying it is. It's only one saw, not a super aggressive chain (it may show more difference under higher load), and I'm not sure the saw was evenly warmed up each time, despite cutting with it a few minutes before testing. However, it does reflect my overall experience. I expected a difference, but not massive at <20* temp difference. I'm sure that some applications (as mentioned snowmobiles) will show more disparity.
I'm not looking for a lot of bashing, but I welcome constructive criticism.

 

[lehman live edge slab]

Happy new year!!

Guilty as charged. I wasted another few minutes this morning testing a saw when it's a little cooler. My results from 2 days ago:
52 * Echo CS-530, WOT 15,360 RPM's, in the cut with a fairly non-aggressive chain being gravity fed 12,600 rpm's
This morning 34* same saw, chain, log, and tank of fuel
WOT 15,700 RPM's, in the cut 12,800 RPM's
I know this is not all-conclusive, and I'm not saying it is. It's only one saw, not a super aggressive chain (it may show more difference under higher load), and I'm not sure the saw was evenly warmed up each time, despite cutting with it a few minutes before testing. However, it does reflect my overall experience. I expected a difference, but not massive at <20* temp difference. I'm sure that some applications (as mentioned snowmobiles) will show more disparity.
I'm not looking for a lot of bashing, but I welcome constructive criticism.

No bashing involved, basing my thoughts on the chart if you lost 13% air density from 0-50 degrees you need to reduce fuel by 13% to keep same crisp tune. And yes in northern mn a 50-60 degree swing through the day is more than possible spring and fall. And if not on same day 2 days in a row can have the low and high temps 70-80 degrees apart. So even if you got by one day running a bit rich the next could be horrible rich at 70-80 warmer than previous day or two. We definitely require a tune more than 2 times a year to be anywhere close to optimum.

 

[Mastermind]

All of this dicking around is why I like M-tronic saws.

 

[bwalker]

All of this dicking around is why I like M-tronic saws.

Absolutely. The average guy can't tune. carb to save his life.

 

[Lions fan]

Absolutely. The average guy can't tune. carb to save his life.

I can, but why *f-word with it?

 

[Mastermind]

Absolutely. The average guy can't tune. carb to save his life.

I can tune right to the edge, but I prefer to just use the saw. My 357XP hasn't had the carb screws touched in years.

 

[redline4]

All of this dicking around is why I like M-tronic saws.

Those wires scare me. Black magic voodoo bullshït.

 

[Loony661]

Those wires scare me. Black magic voodoo bullshït.

All 3 of them!

 

[whitesnake]

I can tune right to the edge, but I prefer to just use the saw. My 357XP hasn't had the carb screws touched in years.

True story. Keep it touch fat and go to work.

 

[Lions fan]

True story. Keep it touch fat and go to work.

Same thing with sleds. Everybody around here has owned multiple carbureted snowmobiles and most of us managed to get around from below zero to just above freezing without incident.

 

[bwalker]

Same thing with sleds. Everybody around here has owned multiple carbureted snowmobiles and most of us managed to get around from below zero to just above freezing without incident.

Yes,bit just like saws there are a few guys that know how to tune smoking everyone else. A properly jetted and clutched snowmobile is night and day from stock settings.

 

[bwalker]

True story. Keep it touch fat and go to work.

Id rather have a perfectly tuned saw all the time via mtronic or autotune.

 

[whitesnake]

Yes,bit just like saws there are a few guys that know how to tune smoking everyone else. A properly jetted and clutched snowmobile is night and day from stock settings.

Of course they will if you enjoy the constant tinkering. Some people do. Some are content with “pretty good” and just wanna ride, or cut, or whatever it may be.

 

[whitesnake]

Id rather have a perfectly tuned saw all the time via mtronic or autotune.

I agree that’s the perfect scenario. I was just referring to carb saws.

 

[lehman live edge slab]

If it’s a saw I’m repairing for someone I have to leave fat so I don’t end up with a blown saw back. I do from certain people get comments about their saw smoking a little more ect. Have to tell them it’s rich on purpose and you can lean it out a little if you want but I won’t be liable if you burn it down. This is the biggest reason I tell everyone who asks advice about a new saw I have them buy the mtronic or auto tune version. No complaints of it being to fat and I don’t need to worry about them messing with the carb.
Some saws I have gotten in are so lean I’m surprised it was still running and some of them that still ran were lightly scored also.

 

[mainer_in_ak]

Same thing with sleds. Everybody around here has owned multiple carbureted snowmobiles and most of us managed to get around from below zero to just above freezing without incident.

Yep! Right now, it's -20 below and my utility sled is crisp as a mother fker, pulling sled loads of wood. Somewhere around the positive teens, she's a smidgen doggy till hot. I dont change a thing.

I've owned about a dozen different 2 stroke utility sleds from about 1995 until present day. Arctic Cat, Polaris, Ski Doo and Yamaha.

Rarely has jetting ever needed changing. Especially the ones with carb heat, like the yamaha I currently run.

Oftentimes, in april, ill adjust idle air/fuel ratio ratio, is about all.

 

[whitesnake]

Yep! Right now, it's -20 below and my utility sled is crisp as a mother fker, pulling sled loads of wood. Somewhere around the positive teens, she's a smidgen doggy till hot. I dont change a thing.

I've owned about a dozen different 2 stroke utility sleds from about 1995 until present day. Arctic Cat, Polaris, Ski Doo and Yamaha.

Rarely has jetting ever needed changing. Especially the ones with carb heat, like the yamaha I currently run.

Oftentimes, in april, ill adjust idle air/fuel ratio ratio, is about all.

They run nice on a crisp cold night! They run the best right before they pop! Lol

 

[lehman live edge slab]

Yep! Right now, it's -20 below and my utility sled is crisp as a mother fker, pulling sled loads of wood. Somewhere around the positive teens, she's a smidgen doggy till hot. I dont change a thing.

I've owned about a dozen different 2 stroke utility sleds from about 1995 until present day. Arctic Cat, Polaris, Ski Doo and Yamaha.

Rarely has jetting ever needed changing. Especially the ones with carb heat, like the yamaha I currently run.

Oftentimes, in april, ill adjust idle air/fuel ratio ratio, is about all.

How old is this sled? Not many carbs left unless it’s like a 550 fan Polaris ect everything 600 cc and up is efi now and I’m glad no more carbs to tune. If I get a new sled it’s likely to be a Polaris titan or voyager with a 600 in it or the 4-stroke

 

[mainer_in_ak]

Old sled: 1994 enticer 2. Pulled plastic skis and paddle track off low miles RMK 700. Choke circuit on the tekei carb is so good, it'll start at 40 below, no primer kit needed.

Bout the only significant carb issue ive had was a polaris trail that sat in Valdez in salt air for years with 1/4 tank of fuel. Fom the tank to both carbs needed cleaning.

Polaris jetted the fan cooled 488 way richer than the liquid-cooled fuji 488 in my widetrak lx. Was a total fkn gas hog till I re-jetted it near how the liquid cooled engines came.

Miss that polaris trail and my widetrak lx with the fuji 488's such bullet proof motors: