I was wondering if by putting on a after market slip on pipe ,,, one from any of the companys that make them,, if you gain 2 to 4 horsepower as they claim u do, and is it noticeable when u ride,,, and when u do ,dose a 4 stoke have to be re- jetted ,, ps what is jetting do and is it bad for the engine to rejet the carb?????????????????????????????:[img]i/expressions/face-icon-small-smile.gif[/img]

 

Just adding a pipe usually does not require you to rejet.

A good pipe will allow more air to pass thru the engine. BUT, keep in mind your airbox is also a restriction to the flow. If you want real gains, you need to mod both. The additional airflow through your engine will require more fuel. Too much air to fuel causes a "lean" condition which can cause excess heat in your engine and potential damage. This is where the jetting comes in. To keep the ratio of air to fuel correct, you will need to rejet. Well worth it for the gains imo.

Along with the pipe, I would get a Uni or K&N, vent the airbox lid (eight 1" vents will run $10-$15), and get a Dynojet kit to help you with jetting.

Good luck!

 

Some companies are telling the truth on how much horsepower you gain by it and 2-4 is about the average people gain with a slip-on. Actually there's a noticable difference when you put one on and the power increase can be from low to top end and prettymuch all the pipes make alot of difference. If you get one I would get a K&N Airfilter and take off your airbox lid. You will need to re-jet buy a Dyno jetkit and that has instructions how to do it. Jetting is the mixture between your gas and air then when you get a slip-on or anything having to do with your intake like airfilter you need to get the mixture right so your engine will run better. When you jet the carb it's the same thing as when people say Jetting.[img]i/expressions/face-icon-small-smile.gif[/img][img]i/expressions/face-icon-small-wink.gif[/img]
P.S. Private Message me if you have anymore questions and I will give you a reply on this thread. Also if you need to know which slip-on to get Private message me and tell me what kind of quad you have and your pricerange then I'll post it on this thread. Most slip-ons are from $190-$300. PM reconranger if you have any real technical problems. PM means Private message.[img]i/expressions/face-icon-small-smile.gif[/img] I hope I helped[img]i/expressions/face-icon-small-cool.gif[/img]

 

I can tell you that after adding a WB "e" series slip-on, K&N with outer wear, removing the airbox lid, and re-jetting I got a tremendous increase in the low end. Under most circumstanses I can be in one gear higher than before the mods and still pull harder. I was a little concerned about running without the air box lid but as long as you do not run thru deep water and clean the filter often you will have no problems. I have heard of a lot of problems with the WB "E" series but have not had any myself. I run 12 discs and like the results. Running the maximum of 18 will open up the top end more but I like the low end pull. As far as the jetting is concerned it is essential with the improved air flow to prevent a too lean condition. With just the pipe you might not to have to re-jet but you will not get the HP increase without more fuel.

 

I think a pipe alone can help depending on temperature and elevation. I think the quads are a little rich from the factory unless you are at sea level in cool weather. These are the same reasons nobody can really pinpoint a jet size for you.

 

how much hp should u get out of a yoshi full system if u can get 4 from a slip on? it must b atleast 6 or 7 rit?