1976 Road Toad won't throttle up

[hieb]

HI Need some help I have rescued two 76 02 Road Toads one runs perfect the 2nd one won't!!!
It will start and idle just fine but will not throttle up, it just spits and pops then dies but will start up fine and idle only.
Here is what I have done so far new bore piston and rings, New Carb all jets clear and getting gas just fine, new points and condenser, getting good spark, even changed carbs from the other Toad but it does the same thing with that carb too! but none of this makes any difference!
Sure could use some expert advise on possible cause's or cures?
I'm 76 years young, and have rode an worked on my own motorcycles for years! but this little 2 stroke has me baffled?
Thanks Hieb

[viclioce]

Since you swapped carbs & it does the same thing, I’m going to take a SWAG (scientific wild ass guess) that it is your exhaust pipe, all loaded up with oil & carbon.

Build a fire outside and place the pipe on the BBQ so to speak. Burning out the oil & carbon build up this way is very easy.

It can take about 15-20 minutes, and watch out for possible flame throwing out either end. One of my Toad pipes did that excessively!

If you pull the pipe and start it and get throttle response, you’ll know. And if you don’t want to run it without a pipe, take that one off and put on the pipe from the other bike temporarily, since that one runs well!

And welcome to the Forum! Victor

[olddogs]

I agree. Sounds like classic restricted pipe syndrome. Idles fine but any attempt to increase rpms kills the engine. I dont know why they idle so well with a plugged pipe, but enough exhaust gas must be able to escape through even the most gummed up pipes. You wont believe how much lighter a clear pipe is than one full of old sludge and oil.

This happens to Hodakas so often someone needs to come up with a catchy name for the problem.

[hieb]

Thanks guys will try that! And let you know if that works>

[BrianZ]

Before burning the pipe, try pulling the spark arrestor/silencer out and see if it helps. I'm not saying you won't need to burn the pipe, but it's a quicker way of seeing if the pipe is your problem.

Brian

[ossa95d]

Since it is a reed valve engine I would also check the condition of the reeds. I have had the very same experience with a small bore reed valve engine of another brand and it turned out to be a cracked reed.