Has anyone run one of these?I just put one on my 425 Magnum with a K&Nn filter and with 7 discs the plug was a real light tan (almost white) I took kout one disc and it got dark on me.Can anyone give me some advice before i start in on it tommorrow?

 

<< Has anyone run one of these?I just put one on my 425 Magnum with a K&amp;Nn filter and with 7 discs the plug was a real light tan (almost white) I took kout one disc and it got dark on me.Can anyone give me some advice before i start in on it tommorrow? >>



You're going about this the wrong way. What you need to do is to replace the disc, intall a new unused plug, and test ride the quad for 3/4 to one mile at 3/4 to full throttle in whatever gear is appropriate. Stop right there with no idling &amp; pull the plug to get a true reading. I'm betting the plug will be gray, which means the engine is running lean. If not a tan or light brown you must re-jet to a fatter main jet to avoid engine damage due to the lean air/fuel mix.
adding discs simply increases the airflow which is why you added the pipe in the first place.
If you aren't able to get some fatter main jets tomorrow, then I suppose you'll have to leave the 7th disc out until you can buy a couple of new main jets I'd get a couple sizes larger than what you now have in case you want to add more discs than 7 later on.

 

I didnt put this on for more performance my stock muffler burned out and it cost more to replace it stock than i gave for this system.But i figured i would have to go up 2 jet sizes.I plan on taking it out the road in the morning and run it a 1/4 mile or so wide open to check the plug.

 

Got the plug to a light tan but I think I will get a 150 main jet just to be safe.That would be one step up.

 

Good idea, it's always better to err on the side of fat rather than lean. Slightly dark brown won't hurt a thing, unlike lean would.

 

The info. posted of adding disks is reducing air flow is incorrect. Adding disks increases air flow, thus leaning it out. This also adds more mid to top end power and adds to the sound level. Removing disks reduces air flow, fatting it up, and adding more low end power(also reduces the sound level).

Since you are adding a higher flowing aftermarket system it will be necessary to rejet, especially since you are running a K&amp;N filter as well. I imagine you are quite lean. I would recommend that you do not ride anymore 'till you can rejet. You might want to look into a Dyno Jet kit, it comes with a different tapered needle as well. Gives nice power gains throughout.

The info on how to check for you main jet is correct. However, you do want to make sure you are looking at the right part of the plug. Go to Trinity Racing's website. There is some very good info on how to read a plug, or do a search under the Yamaha forum.

 

stebob, thanks for calling the typo to my attention. I really knew that as I ran 20 discs in my 4&quot; SuperTrapp for high end.
Also, I failed to mention that anyone who isn't up to speed re rejetting and/or plug reading after the proper test ride may email me for my tutorial &amp; pic on the subject.

 

I stepped up to a 145 main jet.It is a little rich so I am adding a couple more discs.As for the Dyno jet I dont like them I have something like it on my Harley(adjustable main jet)and it is a pain to get set right but nice when the air changes.

 

Rock on Hot_Shoe!! I kinda thought you knew that and just worded it wrong by how you were explaining. Just trying to make sure no confusion.

ftwflh,
Just for clarification, I'm not speaking of Dial-A-Jet. It's not an adjustable main jet. The kit comes with a few different main jets and a adjustable, tapered needle. Your stock needle may be adjustable, too. However, with the thinner taper it will allow more fuel. Since the main jet only affects 3/4 to full throttle this helps clear up everything from 1/8 throttle on up. The jet kit will also come with recommendations on what main jet to use and how many turns to have your air/fuel mixture screw. They are usually spot on, or so damn near close it doesn't require any further changes. It really is a good way to go. JMO!! Also, being in IL you have about the same climate changes I do here. Being slightly rich now is not a bad thing, it will lean out in the winter. Slightly rich will not hurt anything, in fact it's kinda playing on the safe side, especially with the drastic temp. changes we experience here.