Tri z problem

[rddlsn8k316]

I'm having trouble with my 85 tri z. It wants to sputter in the middle of the power band. Idels fine but when I ride it it sputters after take off but will run fine after it is run WOT for a few seconds. I have lowered the needle one clip and was too lean ( got the lean ting). Made sure plug was new and proper gap and air filter clean. Trike is pretty much stock DG pipe and boysen reeds. Did a compression check was about 125 psi cold. My next try is rebuilding carb Local parts house sells carb kit comes with all gaskets, jets, and needles. Any other suggestions??

[TimSr]

125psi sounds awful low to me. I know mine well enough to test it by "feel", but around 180psi sounds more reasonable. Maybe somebody who actually owns a manual can verify that.

Once a determination is made on bore condition, its time to run some full throttle and some mid throttle plug checks, but Id make a wager youre running too rich, and loading it up. Im running pretty much the same setup, and run the needle at its leanest setting, and a 420 main with Blue Marble at 50:1. When I ran BellRay MC1 at 50:1 I ran stock main (470?), and needle at leanest position, but it ran just a little bit on the rich side.

[fattri-z]

The manual states the compression ratio as 7.7 : 1. I get around 175 psi after four kicks with a cold engine.

[Yamahauler]

this is an old thread, but what does the manual say the range of PSI??

[fattri-z]

The manual says nothing about a PSI range, just a ratio.