86 250r

[toyvette81]

well i got my 1st r and its awesome, i got tons of attention just for having such a clean one... in in nc it was the onle one there out of hundreds of 4wheelers i was at the park beating stock 450's and running with piped and jetted ones until top end which was a little odd i was thinking i would have them there and not in the low but o well. and i was doing all that with a filter that looked like it was from 86 lol it was falling to pieces so i had about 4 layers of panty hose and tape on it and tons of filter oil b/c the park is so dusty.... i had the air so restricted that it wouldent hardly run with the duct tape i had on the box cover holes someone drilled in there so i had to take that off to get it to go over 5 mph. it is all stock my questions are, just how much do fmf pipes help vs dg and all the others. i plan on getting a new filter by the way before i ride again it was a last min thing. also what is the stock jet size, mine had a 150 in it when i looked. everything in the carb looked brand new though (cleanest i had ever seen) so it may have a newer carb rebuild in it. also what are the best performance reed valves to get or do they not help this bike that much b/c i see they are very cheap online and not very poppular. and last thing exactly how much does porting the head help the 250r? does anyone know any #'s on how much more % air flow i can get?
and i know its probbly been asked ten thousand times but didn't this bike have mid 40's hp? or am i too high? and how much better is the k&n air filter eliminator then say a clean uni filter with no box top or holes? i jsut didint get that because of mud and all that i have to ride in

[BigGreenMachine]

Keep the airbox, get a K&N to go in it and get a prefilter to cover the K&N. Then holesaw the airbox lid.

Boyseen carbon reeds work great.

Porting works great on ANY twostroke.


James

[Dammit!]

39hp stock but that's at the crank. Rear wheel numbers would be slightly less.

Not much difference between a FMF and a DG. Some people will call them nothing more than "stock replacements" but those people are high (imho). Both are upgrades over stock and will make a difference in power. Paul Turner High Rev pipes are widely considered to be the best performing pipe for a 250R. I've used stock, FMF and Paul Turner all on the same machine. The PT is the top performer hands down.

Aftermarket reeds will definitely help a bit over stock. Not so much in peak power but in improved throttle response and smoother powerband.

Porting is the number 1 performance mod you can do to a 2-stroke. A GOOD port job by someone that really knows what they're doing will have a far bigger impact than just adding a pipe, carb and filter. You won't be taking full advantage of the port job without upgrading those items however. Not all port jobs are created equal. Some people are a lot more talented at it than others so it's possible for two identical machines to be ported by two different people and one could run far better than the other so do some research before letting someone do your motor.

Uni versus K&N depends more on your riding conditions. I've used K&N filters for years in every type of environment and never had any problems. I can see in extremely dusty conditions though, the Uni would filter out the dust better at the expense of some air flow. K&N's without a doubt flow more air. I have proven it to myself beyond a shadow of a doubt. Some people will probably argue that but results are results.

[toyvette81]

yeah its very very dusty around here usually i usually use uni with k&n filter oil. i believe the k&n flows more but not with the oil sprayed on it. i did it with the little thing in the auto stores that holds the ping pong ball up in a tube in one with a fan blowing through the filter but not with the stock filters but when the oil is sprayed on the K&N the ball drops as well... good to know thou we have a really good guy for porting and what not he has done everything we have ever had he has the machines to measure how much more flow he achieved and can achieve so ill probbly do that soon what about the stock jet size? thanks

[Dammit!]

K&N fully oiled still flows better than a properly oiled Uni.

Stock main jet is 145.

[toyvette81]

im sure but K&N says that they are detremental to the engine w/out oil i was unaware that uni filters called for oil at all although i always oil any filter with the dust around here. well i imagine thats why mine runs so rich its got a 150 main jet and nothing to get more air to it at all. im sure a new filter will make a world of difference and a pipe, how high on main jets do most people go with holes in their box cover and a fmf/dg

[Dammit!]

Just read the jetting sticky.