new R this spring

[LTZ400rider]

im selling my z400 and buyin a s-10 then in the spring im planning on buying a new quad. i was thinkin a highly modded 250R. i need some info on these bikes. i rode a 310R with tcs suspension and all this other stuff it was awesome, i loved the center of gravity. i got some questions because im doing research on this.

what is the best year they were made, power wise and part availibility wise.

how much would it cost to make it a 310,330,350 powervalve?

do they break alot? are they easy to fix?

can you switch the head to make it run higher compression. how much do aftermarket heads cost like the pro design cool head?

how often do you have to rebuild them, and do u have to bore it out each rebuild?

[baker250r]

The best year, I cannot really tell you, everybody has their own oppinions on the best year. I own a 88 250r and i love it. To make a 310, 330, 350 a powervalve, you would need to buy a whole new cylinder... running from around 1,500 to 2,000 dollars depending on where you buy it from, aka, CT, Duncan, Baldwin, and many others.

250r's are an old machine, wich means more maintenance than your z400, but they are much simpler to work on than the new quads out these days. It is a 2 stroke, so it will have to be rebuild often, depending how you ride it.

Pro design's heads are like 175 i think, Duncan makes a nice cool head for like 200, i think, not sure tho. they got interchangeable domes for like 23 each.

Rebuild i would say every 30 hours to be safe. IT only costs around 130 bucks to rebuild an engine. no you dont have to bore it out every rebuild, but you do have to hone it. U should bore it and nickaseal it tho, for the big bore kits.

[LTZ400rider]

what does honing it mean? how much would it cost to nikasil it? im guessin that makes it run cooler. oh yea when u say 130 to rebuild it im guessin thats doin it yourself and just pistons and gaskets and rings and all that stuff. oh yea about the domes are they just inserts for the head? they make it have diff compression right?

[baker250r]

honing it means to ruff up the cylinder for the new piston... there is a special tool for it. yea, the 130 is for doing it yourself. You don't necessicatily have to hone it, but it is better for the new piston for breaking in. the 130 does include piston, rings, wrist pin bearing, and gasket set.

Nikasil is a coating they put on you cylinder walls. I have never had it done myself, cuz it is preaty pricey, But it reduces wear in your cylinder i think, and runs cooler. I am not the expert on nikasil, so correct me if I am wrong on any of this stuff.

Yea, the domes are interchangeable, and yea they are just inserts. they do help with compression. u can get a 19 to 22 cc head i think for a 250r.

[zedicus00]

the 88s had the most power stock. and the 88-89 chassis is consitered the best handling. the 86 frame is the strongest stock. 88-89 is a lot lighter then the first 2 years but the 87 is lighter then the 86. 86 uses a shortrod motor (my fav) 87-89 is longrod. 86-87 hav taller 5th an 6th gears so they are technically faster top speed, 6th gear is almost unusable withought a lot of engine work or gaering the sprockets down. 88-89 is a tad shorter wheelbase and sits forward a tad more. most peeple recomend 88's. 89's had less stock power do to a lower compression set up becuz honda wanted to make them easier to start. my preference is the 86, i love the shortrods and the strong factory frame and the seeting on them fits me better.

[LTZ400rider]

dont the short rods have less power? whats the difference. i want good handling and probaly gonna do mostly aftermarket stuff for power so im prolly gonna look for the 88 or 89, i dont think im gonna break the frame so its good. are there any problems with these quads from the factory, like stuff that breaks easily. oh yea one more question how do powervalves work?

[LTZ400rider]

oh yea another question, what is the best carb for the 250R, i was thinkin a airstryker38? whats recommend for stock bore and a 310 or 330cc engine. thanks in advance :macho

[baker250r]

I am not for sure, but I think the long rod is more powerful, than the short rod. As for frames go, I have mine stock frame gusseted, and I race it, and have not had any prblems with the Frame.... but if you run stock shocks with a stock frame, you will most likely break a frame no matter what you do. I have my stock cylinder bored out to a 265, and I am going to be running a 38mm carb this coming season. For a 310 and 330, i would recommend a 38, or 39mm carb. Problems with a stock 250r, is terrible stock shocks, handle bars crimple easily, the frames have weak spots unless gusseted. I am sure there is more, but that is just what i see. I did snap a stock swingarm this year.... but that was what happened when the throttle stuck open off a big tabletop and I overshot the landing.... ouch!

Powervalves....... Powervalves are what are in all of your dirtbikes these days. THey sit on top of the exhaust port, and when you are in the low RPM's they stay closed and the exhaust doesnt go out until the stroke hits the bottom and hits the exhaust port.... when you get into our higher RPM's the valve will open up, and the exhaust will be able to go out halfway down the stroke..... it all works on vacume, and it does create tremendious power on a 250r..... hence the big price tag on them.

[LTZ400rider]

i seen a lrd pipe and it was adjustable 3 ways in length for low mid and top end power. do u have to rejet when switchin all of this. i know jet sizes are totally different from 2 and 4 strokes. what are common jet sizes. like say for a Z400 it would be 135-170 for the main jet. is it harder to jet a 2 stroke? do u have to change the jetting if u use different reed valves?

[#1speedbump]

Stay away from all LRD pipes for the R, they are junk. Your best bets are Sparks MX & TT or ESR pipes. I prefer the Sparks. Your jetting will depend on your mods. YEs if u use aftermarket reeds you will need to rejet with each set of reeds. They are all different and perform different.

[zedicus00]

ehh o.k. lets back the train up a minute. shortrods dont make less power then longrods they just do it in different rpm ranges. longrods naturally lugg better and produce more lowend power so peeple naturally asume they have more power. best carb even with a big bore kit, for the way u ride. prolly a 38mm A/s carb. now onto powervalves. adding a power valve wil NOT make an engine hav more power. what they do is adjust the exhaust port baseds on vacuum so u will hav a wider smoother more usable powerband. also no matter how good the powervalve setup a non PV cylender of the same size will have more topend. and frames, if u race and want to use an 88-89 frame u will need to use aftermarket shocks and u will need to hav the frame gusseted. also plan on replacing the swingarm eventually no matter witch setup u use.

[beak7707]

zedicus00 is right, the short and long rod motors dont really create a different amount of power. The short rods are supposed to rev faster, while the long rod is supposed to have more low end. I have rode both and really cant tell a difference, I also dont think you can buy a short rod crank anymore. My friend locked his up and had to go long rod because honda told him they no longer make the short rod (it was only used in the 86). As for the powervalve no more power is created, it can just be tuned in better for where you want your power. They smooth out the power, you wont have the sudden 2 stroke jerk. That is why some people dont like PV's, most people buy a 2 stroke to have the sudden hit. But alot of racers use PV's because they are easier on the rider, dont make you as tired having to hang on when the powerban kicks in.
I dont believe there is a best year, I do like the 88-89 geometery better however. -1 inch swingarm and the a-arms are up 1 inch, so everything is moved forward an inch on them compared to 86-87. And you said you wanted a modded one so it will probably have aftermarket a-arms and swingarm on it, if this is the case you wont have to worry about them breaking as easily.
If you buy an aftermarket cylinder, I and many others would highly recommend ESR. The quailty is very good and the price is cheaper and they offer great customer support. for a PV cylinder you are looking at 1500-1600 fully ported with high cojmpression head. For the carb I say it depends on what type riding you do. Airstyker, if you want top end speed, they are great for duning and dragging. I feel if you want to race MX or XC mikuins TMX carbs are one of the best. ESR can hook you up with a carb that will match your setup. I also run the ESR TRX5 pipe and wouldnt trade it for anything. But the LRD pipe is a good pipe, almost every racer ran it for a reason. All you need to do is call a engine builder, ESR, LRD, CT, whoever and they will be able to set you up. Certain carbs and pipes work better with certain cylinder kits. First you need to decide what type of riding you are going to do, so you know what porting and compression you need.

[beak7707]

Also the rebuild times only increase as you go up in cc size. You can run a stock cylinder much longer than a big bore. Also dont think the biggest cylinder is the best way to go. I know alot of people who would rather have a 265 over a 310 or bigger. In my opinion the big bores are just more work to maintane. It all goes back to what you want to do with the R. If you want to tear up the dunes or drags then go big bore. If you want an everyday reliable R stay in the 250-310 range. Alot of people run the big bores but I dont want to rebuild mine every 20-50 hours. If you stay with a smaller cylinder, re-ring and hone a couple times a year and buy a new piston at the end of the season.

[LTZ400rider]

i plan on buying a clean 250R with some kind of zps and widen out with nerfs. i just want it to run good look nice sit low and keep me happy. if it doesnt already have it im gonna buy a cool head and some 18 inch klaws, and maybe a carbon fiber race hood and nacs graphics. i already have so many plans with this, just need to get the money :D . hopefully ill find a already modded one and get a good deal. whats the average compression on a stock motor? if it doesnt have good compression whats wrong, rebuild or a whole cylinder? i love this site it has alot of good info, thanks help guys :blah:

[LT250Racer609]

im running a 86 265R with TCS ZPS shocks all the way around....and i dont believe that the LRD pipes are junk considering that every 250R out there has one including the 2 R's we own and the 4 others My friends have...all LRD



my dad has the 87 250R and my friend has the 88 R while i have the 86...every race from the gate up the straight away...the 86 Pulls alllllll.....i dunno if thats only because im 50 or so LBS lighter then them tho:)

Paul Turner is another real good Pipe for the 250R along with ESR or Trinity racing

and If ur gonna go PV...go with 310 or 330...if MX run 350 cause of the new 4 strokers

im also running a 39 MM air striker carb...love it

[wilkin250r]

It seems like you are really stuck on this LRD pipe. I'd advise against it if you're going with a 310 or a powervalve. I'm not saying the LRD pipes are junk. Some people have had really good luck with them, some people haven't. My reason's don't have anything to do with the quality or performance of LRD.

I cannot stress enough how much power is in a port job. (I'm not talking about simple matched-porting where they just clean up the ports. I'm talking actually changing the port timing) A piped but otherwise stock 250r is slightly faster than a 400EX, but even a simple piston and cam in the 400EX will make it faster. However, a piped and ported 250r, running high compression, is way fast.

Now, the particular type of porting depends on your riding style and power needs. If you are going to get a 310 or bigger, it would be absurd to go through the expense of replacing the entire cylinder and NOT get it ported. And if you get it ported, you really should go with a pipe recommended by the person or company doing your porting, because they have researched and tailored that port job to match that pipe.

Yeah, I know the LRD is adjustable. But that doesn't mean it will automatically be the best for a particular port job. Get a pipe that is guarenteed to match your port job. If you send your engine to Sparks, get a Sparks pipe. If you get your cylinder from ESR, get an ESR pipe. If you go with a CT Racing top-end, get yourself a CT Racing pipe to match it.

[LT250Racer609]

In my 265R done by GT-thunder racing (the owner himself did it) im running 110 octane fuel and a high comp. piston...Stage 3 Port and polish...with the LRD pipe...Boyseen rad valve....i walk all over other 250's and ex's...and stay up with a YFZ i ride with that has a cam and is piped...

[LT250Racer609]

however my LRD pipe was cut and re-welded by GT-thunder and is no longer adjustable...he did it to match the porting job...

[JHF219]

mine for sale and it has everything you will ever need the price is negotiable

http://www.exriders.com/vbb/showthread.php?s=&threadid=136485

[trx310]

The 86 R had more power because it lacked a bridge in the intake port. It just wasn't as noticable because the 86 was 35 lbs. heavier than the '88 which is the year that Honda began believing in aluminum. For the serious rider, I suggest the '88 chassis (about 1.8 inches shorter and 35 lbs. lighter than the '86) with the '86 motor. That's how I run mine, with a rebuild every 20 hours(Although it has never been worn out at that time). It is known as the ultimate in our community of riders. Any more questions, pm me.