Build a Low Power 'Dale

[NRath]

I'm needing to go the other direction- less power! I'm going to put a quad together for my daughter and eventually son to ride. They're coming from mini's- 90-100cc and I really can't see the sense in buying a Blaster or 250/300EX nor do I have the funds to do that. I'm thinking if I bump the cam timing to be all top end, then set the rev limiter to about 6-7k, it may tone it down a bit. Thinking about it now, though, that's not gonna' be enough. I could also do some timing retarding in the map. Or, maybe I'd be best off to put a restriction in the intake or exhaust. I will definitely need to put in some kind of throttle limiter in the thumb throttle. It's funny that I don't even remember if ours have a screw in them! I don't remember seeing one.

It would be real nice to be able to do it electronically, so if I wanted to ride it or whatever, it would just be a map change.

What do you guys think is the best way to tackle this?

[Dachshund]

Right off the bat I would agree that corking the exhaust and/or the intake and then make a map to fit it is the way to go.

[wistech]

No need for doing anything other than installing a screw in the throttle limiter bracket thats already on the quad. Using a stock exhaust only loses a little torque below 6000rpm on the bottom end and has very little effect at high rpm.

[4strokemadman]

We had to build a Low Noise/Low Power Dale to meet EU regulations. We just limited the throttle throw at the throttle body for the low power part of it. If you limit the throttle throw you could also have a custom throttle cam made to make the power come on really gradually as well.

[wayneschofield]

I feel that just limiting throttle movement alone wouldn't make one particularly easy to ride for the less experienced or smaller rider.

Stalling them is easy as they are. I think taking a lick off the cams, which isn't too costly, to shorten the duration and perhaps drop the compression a bit would soften the motor nicely. Doing it all on the timing would drive ex temps too high.

I had the same idea and I was having a short stroke crank done at Tim's for my son Luke to make a low-comp, low stress 400cc, but Tim's had the crank so long my son is old enough to manage a 440 now!

A heavier flywheel would help too.

[NRath]

I agree with Wayne, I think the stock quad with only limiting the throttle screw is going to be way to responsive. We're used to it, but these things really jump pretty good with just a little throttle bump. I think there's a TR setting in D&M that'll slow down response too, right? Can this be adjusted enough to have any significant affect? Or is it really just for fine tuning?

I was actually thinking along the lines of 4st's suggestion with the throttle cam or the throttle cable- needing a way to split the cable pull about in half to reduce throttle response. I have an "updated" one sitting in a drawer that I could look at for a starting point, but that seems like I'd be just throwing a dart at whatever profile I tried. And, I'd obviously have to make it bigger but back to the dart thing. Limiting the throttle at the throttle body seems like it would take some destructive mods, unable to be undone. Right?

I'm early in the project now, just getting the front end put back together so it's easier to get the motor out.

Sounds like timing alone is out. It's got an HMF now and I was planning to drop that for the quieter, restricted flow of a toaster. I'm now thinking it would be cheaper and maybe more effective if I just put in a disk in the outlet of the HMF to decrease the outlet size. Then I'd have some map building to do, but it would be quick to undo.

[NRath]

Hey 27, seen any lighter weight springs for the Ohlin's floating around?

[2000ex]

You could also find a short rod falicon with a stock piston to drop the compression drastically

[cannondale27]

QUOTE (NRath @ Feb 9 2010, 11:56 AM) <{POST_SNAPBACK}>

Hey 27, seen any lighter weight springs for the Ohlin's floating around?

Yes I think I have what you need.Free too!

[NRath]

QUOTE (2000ex @ Feb 9 2010, 01:28 PM) <{POST_SNAPBACK}>

You could also find a short rod falicon with a stock piston to drop the compression drastically

I am tearing into the motor, but I'm thinking minimally intrusive changes to make it easier to up the ante a little or go back to full stock.

What do you guys think about just corking up the HMF? Would there be some ill effects I'm not thinking of? Suzuki did it with the LT50, but they did it at the cylinder/header connection. Would it be better to restrict the intake side? I'm just thinking all the extra back pressure of an exhaust restriction could cause some problems somehow.