Is It worth 2 into 1 Carb?

[jmd0346]

Your supposed to set the float level different with the 2 into 1 intake cause it sits at a different angle then when used with regular intakes. Like I said, there should not be anything different with your setup that made it so that carb would not work. We run a 38mm carb on a 460cc 7mill cheetah motor. It doesn't run the bowl dry. From what your decribing, sounds like something was probably broken or missing in the carb if it was smoking badly and "blowing" smoke.

 

 

I was the one who said my buddys smoked bad. It very well could have been missing somehting. He bought it with the 2 into 1 on it.

 

 

This other guy is saying he's running the bowl dry on a 38mm carb. I dont even think its possible to run a carb dry if its setup properly and its functioning properly. When the float gets low the fuel valve opens and allows fuel in. There is no way in hell his engine uses more fuel than a 1/4 or 5/16 hose can supply. More gas goes in the bowl than can possibly be run out. The jet would have to be bigger than the line and fitting feeding the bowl for this to happen. He didnt have it setup right or as you said was missing some parts. Somehow I dont think he'll agree.

[Snopczynski]

I was the one who said my buddys smoked bad. It very well could have been missing somehting. He bought it with the 2 into 1 on it.

 

 

This other guy is saying he's running the bowl dry on a 38mm carb. I dont even think its possible to run a carb dry if its setup properly and its functioning properly. When the float gets low the fuel valve opens and allows fuel in. There is no way in hell his engine uses more fuel than a 1/4 or 5/16 hose can supply. More gas goes in the bowl than can possibly be run out. The jet would have to be bigger than the line and fitting feeding the bowl for this to happen. He didnt have it setup right or as you said was missing some parts. Somehow I dont think he'll agree.

 

Probably wont agree at all.

[IrideA250R]

Modern snowmobile motors are designed and clutched to maintain absolute peak rpm ALL the time. You dont wick the throttle on a sled like on a quad.

 

 

you don't? Where we ride it's not just pin it and forget about it, I can tell you that.

[Snopczynski]

I know its not pin it and forget about it. Clutching on a sled is setup to maintain peak rpm and cycle up in speed if its is clutched right. Anything with a cvt is setup to do this. Another huge thing is that some sleds had cv carburetors which use a diaphragm with vacuum to open the slide instead of a direct throttle cable connection. So this maintains peak absolute velocity in the intake tract. Comparing a sled to a banshee is not a very good analogy.

[IrideA250R]

I couldn't disagree more. Using your analogy, why would snowmobiles bother to have powervalves? Modern snowmobile engines are close to 40 years advanced to our OEM style Banshee cylinders. At a constant speed and throttle position, yes snowmobile clutches do maintain a constant RPM, but if you are off the gas at all, they downclutch and the rpm's drop. The transmissions are different, but the idea is the same.

 

Anyways, my opinion is that a single carb is NOT worth it.

[jmd0346]

I couldn't disagree more. Using your analogy, why would snowmobiles bother to have powervalves? Modern snowmobile engines are close to 40 years advanced to our OEM style Banshee cylinders. At a constant speed and throttle position, yes snowmobile clutches do maintain a constant RPM, but if you are off the gas at all, they downclutch and the rpm's drop. The transmissions are different, but the idea is the same.

 

Anyways, my opinion is that a single carb is NOT worth it.

 

 

 

I dont know shit about snowmobiles so be gentle. What about a snowmobile engine makes it 40 years more advanced?

[IrideA250R]

I dont know shit about snowmobiles so be gentle. What about a snowmobile engine makes it 40 years more advanced?

 

port layout, intake design, reed design, head design, pipe design, ignition design, carburetion/fuel injection, oil injection nozzles in bottom end just to name a few. Basically modern 2 strokes have a lot of years of innovation, engineering, and trial and error put into them.

 

Look at a car engine of 20 years ago even, compared to todays engines, at least double the power, and probably half the emissions. It's much the same with 2 stroke designs.

[Snopczynski]

I couldn't disagree more. Using your analogy, why would snowmobiles bother to have powervalves? Modern snowmobile engines are close to 40 years advanced to our OEM style Banshee cylinders. At a constant speed and throttle position, yes snowmobile clutches do maintain a constant RPM, but if you are off the gas at all, they downclutch and the rpm's drop. The transmissions are different, but the idea is the same.

 

Anyways, my opinion is that a single carb is NOT worth it.

 

I dont know how to make you understand this. Sleds shift up or build speed when under rpm. If clutched properly, the idea behind riding a properly clutched sled is to lay on the throttle, it maintains peak rpm in the highest hp area of the motor the whole time and builds speed from this rpm range. Obviously you have to let off on the sled to manuever in trails or try and make corners, thats what the powervalves and other features of those motors are for. Sleds do alot of things that have been deemed stupid for a banshee on this forum though. 2 into 1 pipe for example, comes factory and aftermarket on alot of sleds. I put in my time as a certified tech at a seadoo/skidoo dealer back in the 90's. First things that usually went when they came in for performance parts was a clutch kit, 2" track, pipes, jet kits, and the silencer boxes.

 

A good example of a pretty badly tuned factory cvt is the rhino. It maintains about 5600 rpm as it runs up through the clutch, then it wings out to almost 8k rpm after it gets through the sheave and it uses the remaining engine rpm from 5600-8000 rpm to build speed.

[IrideA250R]

I dont know how to make you understand this. Sleds shift up or build speed when under rpm. If clutched properly, the idea behind riding a properly clutched sled is to lay on the throttle, it maintains peak rpm in the highest hp area of the motor the whole time and builds speed from this rpm range. Obviously you have to let off on the sled to manuever in trails or try and make corners, thats what the powervalves and other features of those motors are for. Sleds do alot of things that have been deemed stupid for a banshee on this forum though. 2 into 1 pipe for example, comes factory and aftermarket on alot of sleds. I put in my time as a certified tech at a seadoo/skidoo dealer back in the 90's. First things that usually went when they came in for performance parts was a clutch kit, 2" track, pipes, jet kits, and the silencer boxes.

 

A good example of a pretty badly tuned factory cvt is the rhino. It maintains about 5600 rpm as it runs up through the clutch, then it wings out to almost 8k rpm after it gets through the sheave and it uses the remaining engine rpm from 5600-8000 rpm to build speed.

 

I understand just fine how a snowmobile clutch works. I've been around ATV's and snowmobiles all my life living here in Minnesota. My point was (and seems to have been lost) that snowmobile engine technology is leaps and bounds ahead of what is in a Banshee, and in sleds that still use carbs, they have twin carbs because they perform better! Hell, your own carb test on a mild engine shows an impressive power gain just by switching to dual carbs on a mild motor. Imagine a fully built one, damn!

 

Anyways, I see this going no where. I'm agreeing to disagree here. I'll take dual carbs on my Banshee any day over a single.

Edited February 19, 2008 by IrideA250R

[Snopczynski]

Ok, so here is my point. On a banshee engine a single carb makes more low end hp and torque. A twin carb setup makes more mid-top hp and torque.

 

I know how well sleds engines are designed, the bombardier 580 twin in a sled makes 110 hp stock. Thing is, we already dyno proved that at least on my engine the single carb works better down low than twins. The dual carbs work better on the upper end. So, with your original statement, like I said, most sled motors are designed to pull high rpm because thats how they are clutched. Thats why they run twin carbs.