Adaptors and manifolds for larger carburetors

[Deleted member 12676]

Please see my new page on the subject at www.dragonfly75.com/jaguar/intakes.html

Having a quality carburetor jetted and sized right makes a ton of difference in how a bike runs.
It starts better, idles smoother, accelerates crisper, has better peak power, and doesn't foul plugs.

My last dirt bike was a Honda CR250 and my riding buddy had a 250 Gas Gas. We were at 3000 ft elevation and mine was jetted perfectly whereas his was still jetted stock which was for sea level. At that elevation he was running rich and he occassionally had to be pulled back to our cars after fouling the plug. I tried to tell him but he wouldn't listen. I don't see why anyone wouldn't want their ride to be correctly jetted.

 

[Deleted member 12676]

Using the engineering formula for determining correct carb size I came up with this chart. Stock carb size on the Grubee engines is only 14mm. For anything other than a stock non-modified 48cc engine that size will limit top rpm power. I am recommending the 16mm and 18mm Mikuni carburetors. They work really really good.

 

[5-7HEAVEN]

In search for more power, I had two carb adaptors made for my twin-engined MB. Since I was running ADA S1 pipes on the Mits TLE-43 engines, they were running a bit lean. That carb experiment was scrapped when I found more powerful engines and shift kits.

 

[Deleted member 12676]

What engine did you go to?

A shift kit is an external bandaid for an unsolved internal problem. For less money than a shift kit costs you can have a good running powerful reliable bike that doesn't need to shift. All it takes is a little time and effort to get these Grubee engines right.

 

[5-7HEAVEN]

Using friction drive and 1.25" roller, the CY460 and Tanaka 47R engines still dropped out of their effective torque range when climbing steep hills. When that happened, they were dogs. Rpm and torque dropped well below operating range. These engines need high rpm, especially the 460. The shift kit, when geared properly is an excellent way of keeping them in their torque range, especially with ratios as low as 46.36:1 in First gear and 15:1 in final drive. Hills that bested these engines can now be taken with engines screaming or with engines well below redline. JMO, shift kits conquer mountains with proper gearing and the right engine.I'm building another center-frame 460 engine w/shift kit, this time w/8-speed internal hub.

 

[Fabian]

A shift kit is an external bandaid for an unsolved internal problem. For less money than a shift kit costs you can have a good running powerful reliable bike that doesn't need to shift.

Jaguar, i believe you are completely wrong in your assessment of a shift kit, furthermore, i say that a shift kit is absolutely vital to make a motorized bicycle a viable transportation device.

How do you get up these kind of inclines without a shift kit?

 

[Deleted member 12676]

Fab, you wouldnt believe the amount of grunt my 55cc w/reed,torque-pipe had. At 8500 ft I would go flying full speed up hills I couldnt climb before. If you have something thats simple that works good then you have no need for something more complex. And dont say the torque pipe isnt available. I have two for sale at a bargain basement price of $60. Headsmess is going to start making regular expansion chambers at a price of $150!
Your hill that you went screaming up at 6000rpm at 10mph would be a piece of cake for my 55cc. sorry to brag but its the truth

 

[Fabian]

Your hill that you went screaming up at 6000rpm at 10mph

You got it wrong Jaguar. I was screaming up that hill, not at 10mph, but 5mph.

would be a piece of cake for my 55cc. sorry to brag but its the truth

Sometimes a man can stretch truth past the breaking point of keeping a statement truthful

 

[Deleted member 12676]

the typical response to someone highly successful is dislike and even hate. without a monetary purpose I had no motivation to demonstrate absolute proof of my success with this engine. If someone is intelligent and creative then reproducing my success would be no great achievement. The plans for my torque pipe is posted for all to copy. Lazylightning made one and here is what he said: "The pipe
really adds power. A LOT! 2 or 3 times more I would say. It works from the very start and I have a 35 tooth rear gear on the bike. It's really nice."

 

[Fabian]

In fact sometimes my bike is crawling over obstacles at maybe 1 or 2 mph; like the method used by those who ride trials bikes.
Sometimes screaming up hills just isn't possible, no matter how many pieces of cake you have and a single speed system cannot do much screaming in such an environment, no matter how effective the pipe may be - not to say that a tuned pipe isn't effective.