TAV Problem?

[pilotchris]

Hi Folks;

Finally finished my Super Bronc VT1012 but I think I am having TAV problems.

I bought the Bronc with an 8 hp Tecumseh. It had the 60 tooth sprocket on the rear. I ran it down the alley and I remember thinking "geez, this thing is SLOW!" Well, it will be better when I put the 10 HP Tecumseh on it.

The rebuild is now complete. I have a brand new Tecumseh 10 hp and I stepped down to a 40 tooth sprocket on the rear. The engine develops around 3100 RPM at full throttle. It has the original TAV on it from the original Bronc kit. It only does around 22 mph!

During the rebuild, I took apart the TAV, cleaned it up good, greased where necessary, cleaned and polished the belt surfaces, and installed a new belt. This thing should be doing dang near 50 mph!

The reason I am beginning to think TAV problems is that it is the original one and it was slow with the 8hp before I began the rebuild.

Any thoughts from you experts as to where I should start to troubleshoot?

 

[george3]

I dont think they will do 50 mph.

 

[bigrob]

I am no expert on tav's but it sounds like either your belt is to long or your engine is mounted to far back
With the rear wheel off the ground and it revved up does the belt rise all the way out on the front pulley and sink all the way down on the rear?
On my setups the belt has very little slack only enough to let the engine disengage at idle
Take some pictures of your set up it helps :thumbsup:

 

[jeep2003]

definatly sounds like your driven is stuck or something

 

[64fairlane]

I don't know if it's possible on a TAV, but if the driven is mounted backwards, the bike won't pull hard, and you won't get top speed. Also I believe the driven should have asymmetrical sheaves. Do you have matched parts?