The Dark Side Of Beta I.e. Four Stroke

[copemech]

Scorpa was smooth down low, yet had no guts (big torque) on hand down there, as the Beta does have more off the bottom. Yet finding the sweet spot of slipping the chutch while the revs are still building is an art on a 4T. Review the clips of Bou for tidy examples on 4T tecnique!

Ray P. has it down pretty well on his. Keeping just enough in the throttle to keep pulling.

[mobbster]

Hi Billy

What if i told you of an engine that was lighter that the fourstroke

Cheaper to run & maintain,was quicker to act to throttle input, and cost less $ to buy !

It would be a revelation.....

But we already have it.... its a 2 stroke... ha ha

[copemech]

You cannot put a price on the fun factor of a 4T!!!! Whisper quiet the Beta is!

[jimg]

I too have a 2010 Beta 4-stroke, and love it. After getting use to the engine breaking, I only see advantages over the 2-stroke. I only have a couple tanks of gas through it, as I'm not able to ride much this year; it seems to be doing everything easier than my previous 2-strokes. The suspension on these bikes are incredible. I find my bike to come on a tad too strong...I would like for it to come on a little softer....any suggestions?

Billy T....why the change in jets? Stock "seems" to be running fine in my bike...but I'm new to 4-strokes. The Jitsie mixture screw adjuster is a must.

[billyt]

Hey Jim

Why the change in jetting?

I would guess you are riding in Michigan under 1000ft elevation. I am riding anywhere from 800ft > 6400 ft elevation.

Quite a difference indeed.

When one gets a bike from Beta it will be jetted rich to make sure that a customer does not lean seize

the bike. Basically Beta does not know where the bikes will end up once bought i.e. elevation, humidity, temperature so they error

on the side of caution.

The stock CV carb spring is too strong above 1000ft elevation. When riding at higher elevation the spring in the CV carb diaphragm presents too much

force for the thinning air witnessed by the bike responding poorly when the throttle is cracked open.

By you asking to tame the bike down I assume that you have experienced the opposite?

Have you played with the two stage mapping switch under the side panel?

BillyT

Edited May 25, 2010 by BillyT

[rlracer]

What Billy is telling you is the same thing we were doing with the bike in 07 an forward. Once jetted, the spring was the only thing I changed going up in altitude it works that well.

[rlracer]

Billy- I measured my springs-.029-.027-.026-.023-.022 I ran .026 at 800ft.-4000ft. for faster throttle response and .022 at 4000ft. and up.

[billyt]

Hey Ron

Thanks for the info.

I rode a trial on Sunday @ 6400ft elevation and the bike ran flawlessly.

Lots of power on tap.

I used a .025 wire diameter on the diaphragm spring.

I keep the .025 wire diameter in even at 800ft elevation. No slide bounce with this soft spring

on drop offs.

The big change was the iridium plug as it really cleaned up the spark.

I am happy with the jetting now.

[rlracer]

That's the spring I used here works great , the lightest spring will bounce. I used 27.5p- 120m. Clip second from the top with the thin washer under, fuel 50/50 race and pump and used the jitsie fuel screw and loved it. Were are you at on jetting now Billy?

[billyt]

Ron

I have the jetting @ # 20 Pilot, 112.5 main, CV carb spring changed from a stock .027 spring wire diameter to .025.

The clip is second notch down from top.

I am riding at two elevations 800 ft & 6400 ft and this jetting works great for both altitudes.

I have changed the plug out to an iridium plug and that has made quite a difference in how it starts and runs.

Of course the Jitsi fuel screw installed and adjusted as need be for weather, humidity etc.

Also very important to keep the air filter clean as the bike needs to breath with it being a 300cc and the air box a stock size

for a 125, 200, 250, 290cc. The air box really needs to be bigger for the 300cc. I am working on that one! Mmmm...

Billy

[jimg]

Thanks for the insight. So, since you have got this beast dialed in, could you give me a simple recommendation for set-up (jet/spring sizes) for my bike in Michigan; I'm at a little over 1,000ft. By what you mentioned, I should put a slightly lighter spring in and go leaner on the jets.

As far as my comment for taming it down...The 300 definitely has more snap off the bottom than my 290 2-stroke. Several fellow riders in my area have ridden my bike and come back with the same comment. Maybe I just need to get use to it? I heard that Ray had a put on a different throttle on the 09 4t he rode, which made it come on softer.

Thanks

[billyt]

Jim

I would use the exact jetting/spring I have mentioned in my prior postings.

Change the plug to the iridium verion.

Have you tried playing about with the mapping switch!

Ie position 1 soft & position 2 hard!

If you check out my You Tube videos you can hear how it runs.

Let me know how it goes.

BillyT

[jimg]

Thanks! Yes, I have played with the mapping setting switch. Unlike the 290 2-stroke, I can feel the difference (quite notable) on the 300. I prefer the "soft" 1 setting. Don't get me wrong, I love power and quick response and can ride quite aggressive at times. Nice videos!

Who would you recommend to me the get the spring & jets?

[billyt]

Jim

Jetting is such a personal thing. With all else equal (the bike running okay in lay mans terms) what works for me may not be suitable for you.

With that been said most buyers of a the Beta Evo four stroke have re-jetted and re-sprung the CV diaphragm spring.

The parts all in cant be more than $30 USD.

Get a hold of your dealer or call Tim at American Beta to obtain the parts.

If I can help you e-mail me @ billytraynor@hotmail.com

Billy