My electric start full suspension predator 212 build

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culvercityclassic

Well-Known Member
Sep 27, 2009
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Culver City, Ca
It's similar to that one mine is decently longer than that one and has more travel and mine is adjustable dampening they ride really nice. Obviously it's not the same as a 1k fork but infinitely better then any springer.
You have the better quality one made by them, the one I have just had a few springs in it, no oil.
 

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romerider153

Member
Jul 8, 2014
67
1
8
newport ri
That's a bad ass bike I have liked every bike iv seen from you I have been looking at your gold 99cc bike for some ideas lately on my gfs bike where did you get that oil fill and what tap did you use for the cover?
 

romerider153

Member
Jul 8, 2014
67
1
8
newport ri
Perfect what did you use for sprocket sizes? I have a 10 on my clutch driving a 21 tooth which then drives a 9 tooth and am trying to figure out the best rear sprocket. Is 48 to tall you think?
 

romerider153

Member
Jul 8, 2014
67
1
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newport ri
It's just the max torque clutch from bmi 11.20 seems geared alittle low. What gear ratio do you run on yours? I was hopping to have her cruise around 45.
 

culvercityclassic

Well-Known Member
Sep 27, 2009
3,115
177
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Culver City, Ca
You can change it up but that clutch will chatter and heat up if you dont peddle off the line to build up some speed. I could not deal with the max torque issues and went to the disk type.
 

romerider153

Member
Jul 8, 2014
67
1
8
newport ri
Yea I hear yea this bike is for my gf and she has been a huge pita lately so she didn't deserve a 200 dollar clutch we will see how it goes if this clutch doesn't work out I'll give her my cheetah from my Predator bike and try the manual clutch setup on my bike.
 

romerider153

Member
Jul 8, 2014
67
1
8
newport ri
Has anyone tried the Chinese pz19? Got one of Amazon for 12 bucks usually I only go with name brand but figures for 12 bucks what's the worst that could happen.
 
Jan 17, 2015
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ca.
I also got pz19, with the nice filter. Used one on a pred 79, and on a Briggs 3hp. For me there excellent. All I've done is move the clip to lean em out to chocolate burn on the plug. Great throttle response. I don't dump the throttle so I don't know about tuning that response. Like you say for 10$ well worth the finding out how it works for you.
 

Tony01

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Nov 28, 2012
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sf bay area
Since you're running the 212 which has more than double the hp mine did, I think you can safely run 8:1 or even taller. 7.5:1 will give you just over 1mph per 100rpm.. so you can use your tach as a speedometer.

You can change it up but that clutch will chatter and heat up if you dont peddle off the line to build up some speed. I could not deal with the max torque issues and went to the disk type.
greaser_monkey_87 made a thread about tuning the MT. TLDR: alternating heavy/regular shoes with a black spring.

http://motorbicycling.com/showthread.php?t=55901

On my auto shifter the first gear was also low at 12:1 but it only chattered up to 15mph and it didn't bother me much.

I made an XL chart where I calculated maxTorque spring and weight effects based on my own experience, for the 2nd gear shift, in which we only care about full lockup and not start of engagement.

Note that the numbers may be a little high, but when I changed springs between the silver and yellow springs and put the corresponding shoes, the numbers were dead on within +/- 100rpm. Remember initial engagement can be as low as 600rpm under full lockup



I ran a top gear of 7.64:1 and I only had 3.5hp (ratio on the left, yellow spring mixed shoes)
 
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romerider153

Member
Jul 8, 2014
67
1
8
newport ri
Beginner the ratio I'm trying to sort out is for my gfs 79cc build. I know it's kind of confusing since my 212 build page started to turn into my gfs 79cc build. Great info tho
 

Tony01

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Nov 28, 2012
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Oh. It was a 3.5hp flathead. almost double the displacement as the 79cc but only .5hp more.

Try a 9 or 10:1 then.. 9 might be a little tall as well.. it depends on whether you want to turn high rpm's and accelerate better or turn low, pedal assist, and have a good rpm on your cruise..

multiply your engine rpm by the MPH-wheelRPM number .077xxx and divide by your gear ratio, that will give you the mph per engine rpm for a 26" wheel.