Cure to the thumb throttle woes.

[MonkeyBoy]

I have 34 PJ's on my Banshee and have always had to use a twist throttle because of a past broken hand making it impossible for me to hold on to a thumb for very long.

 

I wanted to find a way to go back to the thumb throttle, and I think I have.

 

I used a stock Honda 400EX thumb throttle.

 

You must use a thumb throttle cable (obviously).

 

I tested this last night using a fishing scale.

I pulled max throttle, and then backed of about 1/16 of an inch. Then I put a fishing scale in the thum lever to see the force required to hold it open.

 

Stock Yamaha thumb throttle, 3 month old cable, 34 PJ's: 4.9 lbs.

Stock Honda 400EX thumb throttle same cable and carbs: 2.8 lbs

 

It may not seem like a lot, but it is after a 45 minute Gran Prix.

 

I still need to take the airbox off and make sure that the carbs open fully. There is a stop inside the 400EX thumber that can be ground down to give it more throw if I need to. I probably won't get to this until this weekend,

 

I may swap the old thumber on to take pics and post for you guys.

 

Only thing that is still necessary is a polished throttle cover. I will not allow my Yamaha to say Honda on it anywhere.

[BenBB]

Sounds good MonkeyBoy! I've been looking for another option, the guys that have tried the thumb extenders didn't like them and a twist for me is a death wish, would like to see some pics and hear how it works out.

[KoooPSD]

I think i read somewhere else that someone was using a 400ex thumb throttle and it worked just fine.

[MonkeyBoy]

I will document it this weekend.

[theeechozen1]

if you cut an inch of spring off your PJs it will help a ton too

[MonkeyBoy]

if you cut an inch of spring off your PJs it will help a ton too

341315[/snapback]

 

Will they still close all the way?

[rocketboy]

instead of building hybrid throtlle assemblys or fiddling with fishing equipment id just buy a damn cascade long throw lever ,its only 34$ and has ball bearings for ease and smoothness and its shiny billet bling and longer to prevent thumb fatigue ,gotta love bling with a purpose

[MonkeyBoy]

instead of building hybrid throtlle assemblys or fiddling with fishing equipment id just buy a  damn cascade long throw lever ,its only 34$ and has ball bearings for ease and smoothness  and its shiny billet bling and longer to prevent thumb fatigue ,gotta love bling with a purpose

341401[/snapback]

Yes, but after you see what I have done, you may be surprised. Besided, I can still do that to the Honda Lever, and get an even lower number.

[MonkeyBoy]

Here we go, here is my test. I feel all scientific...

 

First pic is the thottle sides open all the way with the stock thumb throttle. The slide pics didn't come out too good, I should have taken the whole airbox off and the rear number plate too.

 

 

And here is the reading on the fish scale for the stock throttle.

 

 

Here is the Honda throttle open. See the slides aren't all the way open.

 

 

Here is the Honda Throttle, see the stop at the end of the throttle throw.

 

 

Here is is ground off...

 

 

Here is the new tension...

 

 

I also tried cutting the springs. Not much, as I am worried about overdoing it.

 

 

As you can see, it made some difference, just not as drastic as the throttle change.

 

 

All in all, I took almost halved the force needed to open the carbs, and maintained full throttle operation. I think the Honda Throttle is more comfortable too.

 

Next test is a Cascade lever on the Honda throttle. See if that helps.

 

Let me find my lab coat...

[Minkia38]

awesome work - this is why I love online forums - everyone benefits from ones trials!

[Wassup350]

I'm not sure if this is as good as the honda throttle, but i have a single 35 mm PWK. I had problems with just the one carb being hard to pull, what i did was take the spring out of the throttle assembly and cleaned the cable out with my cable tool and some cable wax. It ended up pulling a lot easier, not sure where my fishing scale is but if i can get a hold of one i will see how well that worked.

[MonkeyBoy]

I'm not sure if this is as good as the honda throttle, but i have a single 35 mm PWK. I had problems with just the one carb being hard to pull, what i did was take the spring out of the throttle assembly and cleaned the cable out with my cable tool and some cable wax. It ended up pulling a lot easier, not sure where my fishing scale is but if i can get a hold of one i will see how well that worked.

346208[/snapback]

 

The spring has been out of my Yamaha thumber for a while already, and the cable is kept well lubed. Those mods were already in the baseline of this test.

[Cotton eyed Joe]

The spring has been out of my Yamaha thumber for a while already, and the cable is kept well lubed. Those mods were already in the baseline of this test.

346903[/snapback]

Damn! Better than my idea of paying a midget to open and close my carbs for me.

[tithead]

i went from a thunb throttle quad to a twist throttle quad and the twist gets my vote for easy! id say to everyone who hates a sore thumb should go twist.

[XxMeltIcexX]

i went from a thunb throttle quad to a twist throttle quad and the twist gets my vote for easy! id say to everyone who hates a sore thumb should go twist.

346916[/snapback]

 

A twist is not for everyone tho. I tried it for a while, i nearly killed myself 20 times. I'm gonna get a moose thumb throttle, 114 bucks is better than killing yourself.