If you are going to spend the $ on a carb, you might as well go to a 42mm, the upgrade FOR the HO!

Or email me, I've got the stock 2000 carb in muh garage...

 

You have a 40mm carb in your garage... How much for it?

Greg

 

That's a negative on the 42mm carb. All those who have put one on their Scrambler 500 H.O.'s have found there is a disturbing hesitation / stall on takeoff. It is something you just cannot get rid of with that particular carb. I'm not particularly fond of anything except a good, crisp throttle response. It does help top end a bit more, but I don't really need any more. Besides, there are lots of 40mm carbs out there from guys who have gone to 42's on their Scramblers. I happened to pick mine up for $50 bucks. Even if I couldn't find a used one available, I still would have gone with the oem Scram 500 40mm over the 36 or the 42. Who knows what other problems that 42 would bring along with it when on the SP 500 engine.

Again, for all around good, crisp throttle response, without affecting the runnability, this setup works very nice. I would not want a utility machine that would compromise it's ability to do utility work, run and start well, and offer OEM type performance.

My Sp500 H.O. is really how an atv should run. Unfortunately today, to get that, you must build your own, no matter what make or model. All the mfgr's still have a long way to go. This is not only true of atv's, but auto's, trucks, motorcycles, etc., virtually every motorized vehicle leaves lots to be desired in handling and performance, in my opinion. Many of us can do a lot better job than the factory can ever think about.

 

That's a negative on the 42mm carb. All those who have put one on their Scrambler 500 H.O.'s have found there is a disturbing hesitation / stall on takeoff. It is something you just cannot get rid of with that particular carb>>

Not all. This is not my experience. Maybe all should spend some more time on the clutching. I'm no expert, but my brother and a friend have tried about 6 different combinations of settings and my Scrambler has a fun little goose-wheelie if I give any more than half throttle.

Side by side with my brother's 99 Scrambler- dead stock-
mine is faster with the 42mm carb and clutch tinkering...off the line and at top end.

Rich

 

The hesitation has absolutely nothing to do with the clutching. It's the carb itself. Every one of those 42's does it. That is my "first hand" knowledge, not hearsay. Just call Aaen who sells lots of them, he will tell you there he no way to get rid of it with that particular carb. Some people just don't know what really good crisp throttle response is and are willing to accept that as part of the deal. Not me.

 

I understand you are explaining something first hand, so you must have a point...

But how do you explain that my machine is faster out of the hole than the stock machine?

The hesitation is less than when the machine is stock, that's an improvement, no?

Maybe I should be holding out for more. Thanks for the heads up.

 

Greg, I know nothing about the carbs Polaris uses .... except they are made by Mikuni. Having said that, a 36 mm Mikuni roundslide (used on snowmobiles) can be bored to 39.8 mm. Been there and done that. So it may work for you. Just a suggestion.

Temp

 

You're very close temp, however the variation of 36mm mikuni selected to be used on a Polaris atv can be punched to 40.3mm.

max