Has anyone tried to tillotson tft?

Mini Bike & Go-Kart Parts

toomanytoys

Well-Known Member
#1
https://www.gopowersports.com/tillotson-tfb-mechanical-fuel-injection-carburetor/

My buddy has one he wants to sell me for 40 bucks. He blew his motor before he got to install it and pretty much gave up and sold his roller. I am buying the flywheel and maybe this carb.

I like the idea of no jets and being able to just adjust them like an old school carb. But is it an improvement over a stock carb stage 2 build? Not really wanting to spend 200 bucks on a mikuni right now.

I've spent way too much on minibike parts this year! 80 dollars for the carb and a flywheel to work towards getting my ct200u to stage 2.
 
#2
That is very interesting. It says it is mechanical fuel injection, but not much explanation as to how it actually works.
It looks like it has a bowl, when I think of mechanical fuel injection I think of a mechanical pump and “pills” that get installed kind of like a Hillborn style fuel injection, no float bowl.
For $50 bucks it’s not too bad price wise as long as it performs well Imho.
Please let us know how it performs and how you like it, if you end up buying one.
I thought about electronic fuel injection but I think that requires an oxygen sensor and is kind of involved with battery and electrical wiring.
This might be a good compromise between the two.
 

toomanytoys

Well-Known Member
#3
That is very interesting. It says it is mechanical fuel injection, but not much explanation as to how it actually works.
It looks like it has a bowl, when I think of mechanical fuel injection I think of a mechanical pump and “pills” that get installed kind of like a Hillborn style fuel injection, no float bowl.
For $50 bucks it’s not too bad price wise as long as it performs well Imho.
Please let us know how it performs and how you like it, if you end up buying one.
I thought about electronic fuel injection but I think that requires an oxygen sensor and is kind of involved with battery and electrical wiring.
This might be a good compromise between the two.
I was thinking it would act like an accelerator pump more than fuel injection. My old honda atvs would spray a shot of fuel in when throttle was applied.

I may just get it off him and see. It's only 40 bucks and it sounds interesting!
 
#4
Oh ok gotcha- like an accelerator pump. I’m guessing there is adjustment for the pump?
Having fuel options for these engines is always a good thing imho, if you get it and it works good for you, i’d buy one.
For my regular bike, I am using a jetted chikuni slide carb and I love it due to having part throttle drivability.
Hopefully this carb would give me the same drivability
 
#8
That is very interesting. It says it is mechanical fuel injection, but not much explanation as to how it actually works.
It looks like it has a bowl, when I think of mechanical fuel injection I think of a mechanical pump and “pills” that get installed kind of like a Hillborn style fuel injection, no float bowl.
For $50 bucks it’s not too bad price wise as long as it performs well Imho.
Please let us know how it performs and how you like it, if you end up buying one.
I thought about electronic fuel injection but I think that requires an oxygen sensor and is kind of involved with battery and electrical wiring.
This might be a good compromise between the two.
Here is pics of the absolute ''baddest'' Hilborn injected bike of all time.
''Clyde Rawlings'' T/F 115ci shovelhead,, with engines built by the renowned ''Keith Ruxton'' .
Think he was the first to break 8 seconds on a T/F bike.
Clyde's a friend of mine,, & every time I seen & heard that bike run back in the day ,, it would make my heart pretty much skip.
Nothing like the distinctive unique sound of it, before or since.
Last time I saw it run,, it had over 48 runs on the same engine with around 97% nitro!
Unheard of !!
That bike was absolutely a gorgeous work of art , on top of all that,, & the level of what I try to envision, & strive for,, with everything I build.
If there was ever a bike that had a soul,, it was that one.. ''Pure magic''. :cool:
I

SHOPPHOTOSFROMTHE90S337.jpg
SHOPPHOTOSFROMTHE90S338.jpg
 
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#9
I remember reading a test article about that tfb carburetor shortly after they came out, the person was not really impressed with it. He mentioned a diaphragm that operated on intake pulses to push fuel into the jet and a slide needle that raised or lowered with the throttle plate position to control fuel flow. It was a pain to adjust and didn't make much improvement. This sounds very similar to the small carbs that I have found on string trimmers and small leaf blowers. They are only adjustable by taking the top off and adjusting the slide needle ramp in relation to the pins it sits on to change the fuel mixture. Those things are made so people have no screws to turn for mixture adjustment and most are stuck with the temperamental lean mixture they are set to for emissions. As the parts wear from sliding on each other the needle moves down making for even a leaner mix and more trouble starting and revving the engine. For me, they are nothing more than headaches and aggravation from the epa.
 
#10
I remember reading a test article about that tfb carburetor shortly after they came out, the person was not really impressed with it. He mentioned a diaphragm that operated on intake pulses to push fuel into the jet and a slide needle that raised or lowered with the throttle plate position to control fuel flow. It was a pain to adjust and didn't make much improvement. This sounds very similar to the small carbs that I have found on string trimmers and small leaf blowers. They are only adjustable by taking the top off and adjusting the slide needle ramp in relation to the pins it sits on to change the fuel mixture. Those things are made so people have no screws to turn for mixture adjustment and most are stuck with the temperamental lean mixture they are set to for emissions. As the parts wear from sliding on each other the needle moves down making for even a leaner mix and more trouble starting and revving the engine. For me, they are nothing more than headaches and aggravation from the epa.
Yeah, not so much mechanical injection as us old timers know it. It does operate with a needle on a ramp but you can set the ramp at various throttle positions externally. Although you have to be careful not to apply to much pressure to the adjustment screw while setting it up or else your mixture can get messed up. I bought one a while back and haven't used it yet either, I liked the idea of a stock style carb that I could use and aftermarket air filter adapter on without using that stupid choke hold down that they all come with.
 

65ShelbyClone

Well-Known Member
#11
Similar devices have existed for decades. And decades. The TCT isn't mechanical injection; it's just another type of carburetor. If you look at Tillotson's site, it is designed primarily to improve emissions and starting.
 

65ShelbyClone

Well-Known Member
#13
I missed that the TFB version is described as larger than the TCT. I'd be more inclined to try it, but neither say what the throat diameter is(because it's an irregular shape) nor have a throat diameter equivalent.

I should add that they also say it improves torque. Based on the definition of horsepower, that means power increases wherever torque does, but not as much until after 5252rpm. The TCT is designed to replace a stock carburetor and has a very small D-shaped throat. Any torque gains up to 3600rpm likely come from increased velocity and perhaps improved fuel/air mixing (lowers emissions) which comes at the expense of flow capacity above 3600.
 

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