By the chart you can see how little distance allowance is as long as the driven is fully closed and the driver is fully open don't worry about the belt. Make sure you have some Comet spray for the moving parts it cost more but it works to keep the metal opening and closing for proper shifting. Go have some funnnnn
New guy with a Dunecycle, Tecumseh 8hp
Did a test drive yesterday. All smiles, but it had a really low top speed, maybe 20mph. Full throttle at top speed felt had some sputtering and lots of hesitation. Idle and low RPM was smooth.
I'm hoping to get a lot more top speed, and have a track day next weekend... Any thoughts on why speed might be so low?
I plan to check the main jet and needle position. Might be plug fouling at full throttle.
I'm hoping to get a lot more top speed, and have a track day next weekend... Any thoughts on why speed might be so low?
I plan to check the main jet and needle position. Might be plug fouling at full throttle.
Float level: 26mm
Air screw: 1 1/4 turns out
Main jet: 80
Pilot: 15
(having difficulty finding reliable specs for the carb - I believe this is a mikuni vm22.)
Fuel pump works great and is keeping lots of fuel delivered up to the carb.
I finally got new tires on (18x8.5-8) and that definitely made a difference in performance from the big knobbie tires.
However, it still hesitates and sputters around 3200rpm's (i put a tach on it). Low and mid range power is great.
Top speed seemed fastest when accelerating slowly... Even still it would not hold top RPM without choking and slowing down.
Do you think this is a float level issue? Top speed was probably 30+
Plug did not look lean.
Air screw: 1 1/4 turns out
Main jet: 80
Pilot: 15
(having difficulty finding reliable specs for the carb - I believe this is a mikuni vm22.)
Fuel pump works great and is keeping lots of fuel delivered up to the carb.
I finally got new tires on (18x8.5-8) and that definitely made a difference in performance from the big knobbie tires.
However, it still hesitates and sputters around 3200rpm's (i put a tach on it). Low and mid range power is great.
Top speed seemed fastest when accelerating slowly... Even still it would not hold top RPM without choking and slowing down.
Do you think this is a float level issue? Top speed was probably 30+
Plug did not look lean.
Everything I've gathered so far, my jetting and carb settings are within the ball park of correct.
I'm suspecting something ignition related. I read the following excerpt on another forum regarding a Tecumseh HM80 (My model says H80):
"Be careful with the points and coil insulation!!!!!! The unit would have a steady spark cranking and at idle and would either not rev up or if it did rev up , spark would falter /miss at high rpm with no load and would lose spark when a heavy load was applied. Under high cylinder pressure, the spark would jump from the points cover plate to the wire that goes from the coil to the points.
Solution- tape and silicone insulation between wire and points cover- and motor runs perfectly now J."
I'm going to look into that...
I'm suspecting something ignition related. I read the following excerpt on another forum regarding a Tecumseh HM80 (My model says H80):
"Be careful with the points and coil insulation!!!!!! The unit would have a steady spark cranking and at idle and would either not rev up or if it did rev up , spark would falter /miss at high rpm with no load and would lose spark when a heavy load was applied. Under high cylinder pressure, the spark would jump from the points cover plate to the wire that goes from the coil to the points.
Solution- tape and silicone insulation between wire and points cover- and motor runs perfectly now J."
I'm going to look into that...
Problem solved!
It was a float level issue. Initially it was 26mm, then I found a more reliable spec for 20-22mm. It was totally fuel starvation.
Adjusted it trackside at the race and the trike was ripping!
Long story of other last minute disaster fixes, but in the end I placed 3rd in the main, which I was happy considering 1st and 2nd both had 750cc motorcycle engines on them :laugh: I was a close contender for 2nd even still.
This thing is tons of fun - thank you all for your assistance!
unk:
It was a float level issue. Initially it was 26mm, then I found a more reliable spec for 20-22mm. It was totally fuel starvation.
Adjusted it trackside at the race and the trike was ripping!
Long story of other last minute disaster fixes, but in the end I placed 3rd in the main, which I was happy considering 1st and 2nd both had 750cc motorcycle engines on them :laugh: I was a close contender for 2nd even still.
This thing is tons of fun - thank you all for your assistance!
unk: