Author Topic: Only 50 mph top speed  (Read 1236 times)


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Only 50 mph top speed
« on: July 31, 2017, 12:44:01 AM »
Hi there,

I bought a used Fiddle II 2009 about 4 years ago ($900) and drive it only 1-2 times a week in the summer. Otherwise it is stored outside with a tarp over it. 3 weeks of snow here. It only has1200 miles and runs smoothly. Starts up reliably after two turns and idles well at low rpm. I like the large seat that stores 2 helmets and provides a comfortable ride with my girlfriend. It has enough power for running errants in the inner city and a "huge" advantage finding parking.

Last year it got stolen and I found it 3 blocks away, dragged sideways on the pavement to an intersection with a street light. They tried to start it and ripped off most panels and cables. But I fixed it with glass and epoxy from the inside. A lot of the plastic latches and hooks were broken off and some I repaired with wood, aluminum and epoxy  The dark brown floorboard was in bad shape, when deformed, it cracks or leaves white stress marks that are hard to iron out even with a heat gun. Had to get new mirrors and handle bar grips. In the process, replaced all lights with LEDs except head light  Anyway, with some plastic surgery and buffing, I got it back to look great again from 6 feet distance! The thieves destroyed the ignition key barrel but I found a replacement from England on eBay ($60). These are not so good. The first one didn't engage the steering column lock and the inner "crank shaft" broke after operating the manual trunk lock a couple of times. The next one lasted just 2 years before it broke again. Today I installed a third one that locks the steering bar well. Let's see how long it lasts...

Now, what I really wanted to say is that my Fiddle II only gets up to 52 mph indicated (49 mph GPS) on level ground with no wind! This forum makes me believe that I could expect 60 mph at least. Some here say 70 mph or more! (My tires are standard US market 3.50-10.)

So today I changed the stock rollers to Dr. Pulley's sliders 18x14 12g. I cleaned quite some belt residue from the inside of CVT housing and there was only a little pad dust in the clutch bell. Also inspected the air filter which was very clean. The belt is still factory issue BANDO 799x19x24 although I measured just 17.1 to 17.3 mm width all around.

I ran a flat straight stretch both ways today (it was windy) before the replacement and 4 hours after (had to manifacture the variator arresting tool from metal conduit pipe). Before with stock rollers: 50 mph back, 52 mph forth versus Dr. Pulley sliders: 49 mph / 54 mph. Interesting, but just 0.5 mph increase in average top speed. I also did a test on a very steep hill. Started from 0 and memorized the spot when I was at 30 mph with the original rollers. With the Dr. Pulley sliders, I might have been 31 mph at the same spot but overall, the new sliders didn't change anything noticeable in acceleration or top speed. I weighted the original rollers to 14.00 g. Just as (some) other people posted.

I really would like to get to 60 mph. This would help keeping up on urban highways and rural roads with 55 mph speed limit (where everybody drives 60). No need to go faster or on an interstate. Wouldn't feel safe. I don't have the setup or expertise for major engine or transmission work but looking for ideas on tuning.

Should I try 14 g Dr. Pulley sliders? Different belt? Should I have a mechanic adjust valve timing? Carburetor jet mod? Is there a simple exhaust modification? Opening up the air restrictor? Any ideas welcome!

I don't want to spend a lot of money but would invest some time to tinker. I also believe the professionals saying a racing CDI is not the answer.

Thanks everyone who posted on this forum. I learned a lot from you!


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