My 1st build - CB2 inspired rack mounted, scissor lift, FD

Good morning CB. The data sheet for my HF 79cc states max torque at 2500 rpm and max rpm at 3600.

I'll rerun the numbers using those numbers.
 
I assume you are going to run it with out the governor?
You can figure your top speed in the mid 4k rpm range.

The little Preddy will easily do that.
 
You can just remove the link from the governor arm to the carb and fab a direct cable set up.
This would leave the governor intact and all you would have to do later if you wanted to use it
is to reconnect the link after removing what ever set up bypassed it. The governor will work normally disconnected and nothing will drop into the engine.
 
So today I cut out three 3/4" plywood discs. I had more hole saws than I thought. They ended up at 2.25", 2.8125" and 3.25". I'll do some math later tonight.
 
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OC_Hugh said:
Any chance you have a photo of the changes you made?
Click to expand...
No dont have a Preddy any more.

Just remove the small rod from the carbs throttle valve to the governors
control arm. Move the throttle control to about 3\4 throttle to keep some load on the governors internals.
 
A kid on youtube took two zipties, cut the locking end off one and then ran the uncut ziptie through the center of the governor spring. Then he slid the locking end onto the uncut tie far enough prevent the spring from stretching. This is a 212cc predator. I'm going to try it on my 79cc.
The images are from slightly different angles so keep your attention on the rusty looking spring.

Before
Screenshot_2017-07-26-05-00-48_kindlephoto-5067879.jpg


After
He slid the uncut tie in from the right and then slid the cut locking end on from the left effectively preventing it from stretching.
Screenshot_2017-07-26-04-57-40_kindlephoto-5171745.jpg
 
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That would work, but you are having to move the entire
hand control linkage with the throttle cable vs just the carbs throttle. Might be a bit sticky. Give it a try, if it works to suit you it is an easier way.
 
I just did something that made me shake my head and laugh at myself. I'm trying to figure out a simple way to attach the front portion of my engine and roller mount. The bike has an aluminum frame. The rear triangle seemed pretty wimpy, size wise, compared to the center portion of the frame so I grabbed a magnet. Sure enough it's steel.

Here's where I got stupid. The magnet also stuck to the aluminum frame. What? Move it here, move it there, sometimes it sticks. I determined that the center upright part is steel but the two diagonals leading from the bb up to the front fork are aluminum. Did they braze steel to aluminum? Can you even do that? Some sort of high tech adhesive? This is a cheap bike, so doubtful. I touched the magnet one more time to the center post and noticed that it didn't stick as good as it did to the rear triangle. It finally, FINALLY, dawned on me. The magnet was "sticking" to the steel seat post inside the aluminum frame. Face palm moment.

I went from a minute of feeling stupid to about 4 seconds of feeling smart that I figured it out before I felt stupid again for taking so long figure it out. That's when I started laughing. So whether you laugh with me or laugh at me, I hope get a chuckle out of that.
 
I was looking at the linkage btw the governor lever and the carb. I removed the rod from the throttle control to the butterfly lever. It ran fine except I had to turn the idle screw in a bit to keep it from dying. It stills idles nice and low but when I move the butterfly lever it revs much higher than when governed.

I watched the governor lever and it does it's little dance but now its dancing alone. I left all the springs alone except one that moved a bit to increase the tension so the engine would reliably return to idle when i let go of the butterfly lever.

I'll see if can upload a video clip and perhaps someone can advise me.
 
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