whats the easist and cheepist wat to get more power out of a 4stroke w/o getting a new pipe, piston, ect. also, does k&n filters realy help?

 

K&N filters do work, also you might look at the uni filter.. The biggest improvement with the new filter will be when you get a new pipe... You have to move air...more air in..more air out...get the picture and if the pipe leaving restricts the flow because your new filter is letting more in then you dont get as much benefit. Hope that helps

 

i was thinking about getting a fmf or something, but are they louder then the stock for the rancher? how much louder?

 

I run the FMF MegaMaxII with 6 disks, and the quiet core on the Rancher (and K&N). The power increase is very noticeable. The more disks you run, the louder it is. Running more disks favors high end power, and running fewer favors low end power (6 is a happy medium). I would say the sound level is half way between stock and the level of the average piped sport bike.

 

Here is some crap you can do, hope this helps!!

The Trick ....Vent the airbox lid and install a new after market air filter. This increases air flow to the motor.
The Gain ....Doing this can give you a 5% to 10% performance gain throughout the power band.
There are 2 ways to do this ,
#1) Buy an airbox lid with vents in it. #2) Make your own.
I vented my own vented airbox lid by simply boring 8 ,1 inch diameter holes. Obviously having holes in the lid means your airbox is no longer water proof.What I did to help keep some of the mud dirt and water was to place a piece of very open celled foam on the inside of the lid. Then I used a piece of screen with 2 screws to hold it in place. Works Great !

Please Note ...Because you have now increased the air flow to the motor,you will need to rejet the carb richer and possibly raise the needle to compensate for the added air.



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STEP 2

The Trick ....After market exhaust.
The Gain ....5% to 10% more for a total of about a 10% to 20% increase.
Please call around to see who makes a pipe that best fits what your looking for.
Please Note ...#1) You will once again be required to rejet the carb and possibly raise the needle. #2) Purchase a pipe that falls within the guidlines for loudness and has a spark arrester. The last thing we want is someone complaining about some idiot making too much noise and catching the woods on fire. We want to improve our image not disgrace it. You may also want a rebuildable pipe so you can replace the packing.



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STEP 3

The Trick ...A Bigger carburetor. Just go to the next size up,unless you are going to perform further modifications.
The Gain ...5% to 10% more for a total of about a 15% to 30% increase.
Do some comparison shopping when purchasing a carburetor. You can get carbs with polished bores and chrome slides.These are an additional cost. If you do some homework you can also specify the cutaway on the slide and the taper of the needle.
To be on the safe side, you can get one exactly like you have now ,just bigger.
Please Note ...#1) Once again you need to rejet #2) With a much bigger carb, you may be required to remove the airbox completly.
#3) If further mods are being made, then you should consult your engine builder for the correct carb size to use.



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STEP 4

The Trick ...A Big Bore kit. Increase the CCs of the engine.
The Gain ...10% to 20% more boost for a total of 25% to 50% more . Now we are getting somewhere!!!
If you are going to go this far,now would be the time to also consider putting in a higher compression piston.(Can't forget about Bottom End power)
Please Note ...#1) As you bump up the compression, you will need to use a higher octane fuel to take complete advantage of these modifications.
#2) Again you will need to adjust the jetting of the carb.



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STEP 5

The Trick ...Stroker Crank.
This modification changes the length of the stroke,or in other words,it increases the distance the piston travels.
The Gain ...10% to 25% more for a total of 35% to 75% power increase. Impressive !!!
This is the one mod that can be performed without doing the previous mods. But why would you want to do that?
Please Note ...#1) Some special modifications may need to be done to the piston and or the engine cases in order to make clearance for the connecting rod.
#2) Also rejet once again.This time you may have to jet the other way (leaner) because the longer stroke draws more fuel.



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STEP 6

The Trick ...High Performance Cam and Heavy Duty Springs.
Hey , why not ???
The Gain ...another 10% to 15% for a total of 45% to 90% Power increase.AWESOME !!!
Please note ...This modification holds the valve open for a longer period of time.This allows more fuel to be drawn into the cylinder,But I guess by this time fuel economy isn't an issue. Don't forget to rejet.



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STEP 7

The Trick ...Porting the head.
This is just a fancy way of saying ,Opening the intake and exhaust passage ways.
The Gain ...5% to 10% for a grand total of 50% to 100% power increase. Who would have thought it ?
Please Note ...This should only be done by a qualified engine builder. This modification,if done improperly can result in LOSS of engine performance.

Also , You might as well do a valve job while you have it apart ,just to make sure they don't leak.

 

Don't wast your time or money with all that stuff, get a Nitros Oxide kit. For $350 you will get an instant 10-13 horsepower and the bike will be reliable and smooth running. I say this because I see you have a 2X4 rancher, and I don't expect your are going to be MX racing with it. But for play riding and drags you can't beat it. It's easy to install and your could take it from bike to bike if you ever sell it.

I had one in an old atc185s and man did it run, used it for 3 years of hard riding without ever needing a rebuild. The power was diabolical!