Saw that you did pipe it. Once I piped mine with the stock carb it would take some to time to get it moving. I did open the jet up and it improved. I also went with a 24mm Kiehen carb, and swear I have a 130 main in it.

 

Hmmmm it's an Alpha Sports... I haven't seen them up close.. though I'd wonder if the functionallity is similar to an LT80?? Pulley in front with rollers, and a friction clutch with a drum and springs in the rear? If so... It would seem as though your stall speed is off... That's usually worked @ the rear clutch... The most common thing to do is remove weight off of the 3 arms IE: lighten them... This then requires the engine to rev higher to engage the rear clutch. ALso stiffer springs on the (rear) clutch arms adds more of the same effect. The one big rear spring controls the rear pulley rate and tension.. My understanding on the front is: different roller weights control the shifting from high to low speed... What your after is getting the (2) to work together... A fair amount of hair can be lost in this process.... Again with the Alpha ... I'm not sure if it's similar to the LT80 design, so possibly this may be off...?

Rude Dog

 

It's the same set up as Polaris, Eeton, Kasea etc etc. But they must be similar to the lt80 because I think you nailed it. I drilled my stock clutch out, the results were OK with stiffer springs. But the aftermarket clutches are aluminum and weigh about 1/3 of the stocker. Worked better. That's why I recommended that route. [img]i/expressions/face-icon-small-wink.gif[/img]

 

I was working with Billy at WRH but I had to get the parts in time for my boys birthday. Billy said he might have it in time and unfortunately he did not. Im undecided what upgrade would be next either the 24mm carb or a racing cluth. The quad reallyl hauls once it does get going but the rev limiter keeps it from anything further. Gonna try the gearing next since its the least costly. I told the mechanic not to return the quad until the alpha sports is popping wheelies! He assured me he will work on it till its right.

 

Going agianst what the others said, I don't think its the clutch. (did you change all the springs, (3 small and one big?)

I modified my Dinli, with-
Koso pipe- dog at first, the opened up the jet, worked better.

Installed the new weights, clutch springs and rear pulley spring. Also put on a new CDI and 24 mm carb with a 130 main ( I beleive), runs like a raped ape. With the stock clutch pack.

I think you need a bigger carb and get rid of the stock CDI. I know its not cheap, but thats my input. I think that 16mm with a pipe is killing your ride.

 

sssduane, I don't think that would explain why it bogs and then takes off when he picks up some speed. That has cvt written all over it imo.

 

i agree with raptorlegs. i ran a modded motor with stock carb for a long time and my son won many races with it. either clutch and variater or since you added a 54mm cylinder you could have a large squish area which means low compression.

Mark

 

Is the engine revving but the bike just isn't accelerating??? Just finished modding out my youngest boy's this spring, and using the 4 gram weights they sent it screamed but didn't accelerate hard until halfway down the straightaways. replaced all weights with 4.5 gram weights and it is much better now... it accelerates hard from the start now. Am running the yellow rear big spring and koso small rear clutch springs (2000 rpm I think). On the engine side, what is your compression now? I hope you get it dialed in.

Hqr109, where did that trick looking rear swing arm on the 2003 pred 90 in your pictures come from???

 

thats riley holts predator, son of billy owner of wrh racing. the swingarm was built by kenny vaughn of k-fab in texas. it is all aluminum. you ought to see the one thats on it now. it has a honda style round billet aluminum bearing carrier on it. how you like the filter box on the front bumper i built for it. worked real good too.

Mark

 

I agree also Rap, if all he did was replace the weights with no springs. The thing is with all the mods he has done, its hard to troubleshoot. With these little bike, just changing a filter to aftermarket without jetting will make them fall on their faces, let alone a big bore, pipe and possibly just the rollers.