OK, I went for a ride. My quad does the same as his but at a lower speed, 60 km/h. This happens when my snorkles are turned towards the rider, the open end facing me. The power is increased but like I said stumbles at 60 km/h.

I turned the snorkles facing into the wind, WOW! Power galore, this thing runs like a raped ape now. It runs good everywhere except when I run 85 km/h or more, maybe its 90, not sure, it will backfire when I let off the throttle and there isn't much power when I get back on the throttle. I didn't test this much, didn't like putting the quad through that torture.

I have an outwears prefilter so I decided to play with that. I slapped it on the snorkle with them facing the front. I get stumbling and hesitation at 60 km/h again, these things seem to block alot of air!!

I decided to try the snorkle turned towards me with the outwears pre-filter on for kicks. It stumbles and hesitates at 40 km/h or so.

So as it turns out my snorkle design is good for racing, not mudding and trail riding. If I have to turn my snorkles forwards then they will probably collect mud and water and defeat their purpose and the pre-filter blocks to much air it seems.

So what I'm thinking is that I have a rich condition, except for when I have the snorkles facing the front and at high speeds. I probably have a lean backfire then, right?

Does anyone have any ideas of what I can do? Should I run the snorkles towards me and jet down? This shouldn't affect my power alot and may save a little fuel, right? Or should I put on a multi head end on the snorkle so it can draw in more air while facing me? Or design a small box up front that they run into and draw air out as it needs? Or slap on a 3" end and funnel it down to my 2" snorkle?

I need some ideas, thanks for reading. The video will be up on Monday or Tuesday. Its a good video, step by step.


PS: How hard is it to change the needle and the jets on the brute? Do I need to remove the air box? I hope not because my snorkle design doesn't allow for removing the airbox very easily, lol.

 

I made the down piece, didn't help. I gained a few more KMH out of her before she sputtered and hesitated.

I even tried to make the down piece go behind the fender where the air was stable. Worse!

I removed the down pipe and did a little test. Found two markers and did a few different runs.

Snorkle facing the rider, 68 kmh and stumbling in the 60 - 70 kmh range.

Snorkle facing the front, in the wind. 71 kmh and no stumbling at all. There is backfiring at 85-90 kmh when I let off the throttle.

Snorkle facing the front, in the wind, choke wide open. 73 kmh and no stumbling. There is very little backfiring at 85-90 kmh when I let off the throttle, runs pretty good.

My front plug is a light tan. I didn't use any new plugs to see my extact jetting. I can still ride my quad with the snorkles facing me, I just can't go past 60 kmh, lol.

Any help would be appreciated.

 

what kind of mods does that prarie 650 on your website have ? that thing is bada$$

 

Thats my old quad, I traded it in for my Brute Force. It had 26" outlaws, black secondary spring and module for more low end power.

 

Results from a stock CDI.

Two headed intake runs bad, seems to not want to suck any air at all.

3 inch to 2 inch 90 degree elbow facing the rider, the quad runs alot better. It seems that it sucks in more air, I forget at what point it started to stumble and hesitate at. Its a really ugly solution, something I would never consider.

45 degree elbow, performs the same as a 90 degree elbow facing to or away from the rider.

Removed all elbows and just have the intake flush with the fender. Quad runs nice, no hesitation or stumbling, no backfiring after letting off the throttle. There is a flat spot around 77 km/h though.



These are now my results with the Dyna CDI.

2" 90 degree elbow facing the rider, I can now get about 8 km/h faster before it stumbles. Turn the elbow away from the rider into the wind and it stumbles at the top end, 95 km/h, when I let go of the throttle.

Removed all elbows so the intake is flush with the fender. Runs nice again, no backfiring after 95 km/h, the flat spot is still there but not as bad as before.

Its my conclussion that before the CDI I was running rich. When I was running with the snorkles and when it was stumbling and hesitating I put my hand partially over the snorkle, the motor would hesitate even worse! If the stumbling went away that would tell me it was running lean and removing air would correct the fuel air mixture. This did not happen, this tells me I am running rich.

So now I need to find out how to get my jetting right, the CDI helped but it didn't lean it out enough to make a big difference. I'm thinking of adding a second air intake, like a 1 inch hose or something. I don't want to touch my jetting because my airbox is a pain in the *** to remove.

Although I am thinking of upgrading my snorkles, again, lol. A muffler shop should be able to bend the size of pipe at the proper angles that I need pretty easy. That means I can remove my airbox easily.

Let me know yours thoughts.