81 250r parts/help/advice

[f76]

Picked up a rough 81 250r this morning. 3-4 years ago had top end rebuild, <10 hours run time, then sat in the shed. Good compression, tranny went through all the gears. Shocks are all good. Intake boot is shot, choke on carb is busted and held on with wire. Reeds and cage look good. I want to build a solid ridder with some extra "go" to it over stock. It doesn't need to handle massive jumps or be the ultimate racer. Just a fun ridder to take on some dunes, trail riding, and snow. Yes I know it won't touch a liquid 250r, I don't have the money for one of those.
This will be my first 2 stroke trike so I welcome any and all advice. I have old lawn boy 2 strokes, chainsaws, and trimmers so I'm not completely 2 stroke illiterate, however 250r specific advice is what I'm after.
For my build here is what I'm thinking for bolt on go fast parts:
85 250r keihin PE 34mm carb or something similar.
Fl350 odyssey intake boot.
Uni filter with outerwear, ditch stock airbox, build a free flowing replacement unit.
Probably a DG pipe. Won't be able to afford a vintage good one I'm sure.
200x front end swap.
Trx 300,400,450 rear hubs.

If any of this sounds wrong or there are better options, please share.

Of course some pictures!



Thanks for the help!

[Bren_downe]

PE 34mm is good, PJ 34 would be better so I'm told. I believe the fl intake only works with the 300 kit? Ditch the 200x swap idea, the fatty front tire is bad ass! Mine had the swap done when I bought it, I swapped back and didn't notice any performance loss. The trx hubs are great! I have em, with the fatty front and the wide rear you can lean in And the turns really hard. Enjoy your first smoker, you'll be hooked. Keep your eyes open for a vintage pipe, I got my bassani from a member for $45, just needed paint.

[jb2wheels]

Looks good in pics. Looks like a good find.

x2 on the fat front.

I'd leave the airbox, too, but I hate cleaning filters.

How's the seat pan?

[f76]

The sides are pretty rusty. I haven't taken it off the plastic yet but I'm hoping to either save it or graft in new pieces where needed.

[manbearpig]

yup. keep the fat front tire. its what gives the gen 1 250R (81&82) its character.

as far as carb setup, somewhere around 34MM is where you want to be unless you've got some wicked porting and are drag racing or running Ashtabula. decent upgrade is a 30MM Keihin round slide from 83/84R (30MM) and a better upgrade are the 34 Keihin PE (round slide) or PJ (oval or "flat" slide) from 85 & 86 250R respectively.

Intake boots can be a little tough to find. I have switched over to vintage aftermarket intakes that have interchangeable Mikuni snowmobile boots for any size carb. Makes swapping boots for bigger carbs easy. also makes finding boots a snap. If you dont want to try to hunt one of those down, you can find an 81-84 250R boot and heat it up and stretch it to fit the larger carb. be wary of cracked, repaired, or super stiff boots. FL350 intake boots are hens teeth.

exhaust isnt that tough to find. be patient and watch ebay for an old unidentified pipe and silencer setup to pop up. It doesnt really matter what it is, it will flow better than stock and will weigh half as much.

i see you're missing the front caliper. the 1983-1987 200X and 1981-1984 250R all used the same front caliper. you will need to use an 81/82 caliper mount for any caliper you choose.

[barnett468]

.
EXHAUST

Here’s some examples . . If you buy a $200.00 DG pipe, you still need to buy a $110.00 DG silencer . . The Bassani below is a real vintage cone pipe, and my guess is that the guy would take $200.00, however, it has a heavy steel silencer but who cares . . You could buy that pipe and buy an aluminum silencer and adapt it, this would be very cool . . Another option is to buy the DG silencer, I think it fits the stock pipe and the DG pipe [call for info] so you can try it on your stock pipe . . It will give you a noticeable increase in power which might be enough for you . . If it is, then you saved yourself $200.00 . . If it isn’t, you can still buy the DG pipe.


DG silencer p/n 20-2214 . . $109.00

http://www.ebay.com/itm/81-82-Honda-...-/400607021180


DG pipe only . . $190.00

http://www.atvparthub.com/01_2011_DG...IZwBoCjCPw_wcB


Used vintage Bassani cone pipe . . $250.00

http://www.ebay.com/itm/1981-honda-a...p2054897.l4275


DG pipe, no silencer . . $209.00

http://www.ebay.com/itm/like/2719259...466&rmvSB=true

[f76]

Sorry my pictures don't include a picture of the silencer. It has a pk racing silencer on currently. I would assume that will work with a dg pipe or the bassani listed?

As for the front tire, I do like the looks of a big kenda front max on these r's. I have a 200x front end already laying around so I wouldn't have to go find one. I know the fat front tire gives this machine it's "character", but I'm not going for a restoration here. If the 200x front end offers better performance and ride quality, I'm going that route.
Thanks for all the help so far! B

[barnett468]

Sorry my pictures don't include a picture of the silencer. It has a pk racing silencer on currently. I would assume that will work with a dg pipe or the bassani listed?

As for the front tire, I do like the looks of a big kenda front max on these r's. I have a 200x front end already laying around so I wouldn't have to go find one. I know the fat front tire gives this machine it's "character", but I'm not going for a restoration here. If the 200x front end offers better performance and ride quality, I'm going that route.
Thanks for all the help so far! B

If the DG silencer fits both the stock pipe and the DG pipe, the PK will also.


The 81 250r has 6.7” of front suspension and the 200x has 7.7” . . The type of valving on both is the same, therefore, so you will basically only be gaining 1” of travel by installing the 200x forks.

You can actually cheat a little and install around 5/16” of AN style flat washers in the bottom of the damper rod cones to increase the suspension by an additional 5/16”.

If the fork springs are too soft you can buy stiffer ones.

http://racetech.com/ProductSearch/3/...TC250R/1981-85

This being said, since you already have the 200x forks you don't have anything to loose by trying them other than the narrow tire which has its advantages and disadvantages.


This seal on the damper rod wears and is available from the site below . . There are 2 on each rod.

http://www.cmsnl.com/honda-atc250r-1.../#.VcF8u7XLDdU

[f76]

Good information barnett, thanks!
Here's a picture of the pk racing silencer.

And the hondaline big red towing package...for a 250r...

[f76]

Well for kicks and giggles I glued up the intake boot cracks and cleaned the carb out, slapped it all together using the questionable gaskets which were practically half rtv silicone from the previous owner. Once it fired up, it took off and ran without the spark plug wire attached, which was my attempt at shutting the screaming motor off. The excellent compression, combined with an air leak somewhere is my guess at why it turned into a 2 stroke diesel. Any other thoughts or things I should check?

[yaegerb]

Picked up a rough 81 250r this morning. 3-4 years ago had top end rebuild, <10 hours run time, then sat in the shed. Good compression, tranny went through all the gears. Shocks are all good. Intake boot is shot, choke on carb is busted and held on with wire. Reeds and cage look good. I want to build a solid ridder with some extra "go" to it over stock. It doesn't need to handle massive jumps or be the ultimate racer. Just a fun ridder to take on some dunes, trail riding, and snow. Yes I know it won't touch a liquid 250r, I don't have the money for one of those.
This will be my first 2 stroke trike so I welcome any and all advice. I have old lawn boy 2 strokes, chainsaws, and trimmers so I'm not completely 2 stroke illiterate, however 250r specific advice is what I'm after.
For my build here is what I'm thinking for bolt on go fast parts:
85 250r keihin PE 34mm carb or something similar.
Fl350 odyssey intake boot.
Uni filter with outerwear, ditch stock airbox, build a free flowing replacement unit.
Probably a DG pipe. Won't be able to afford a vintage good one I'm sure.
200x front end swap.
Trx 300,400,450 rear hubs.

If any of this sounds wrong or there are better options, please share.

Of course some pictures!



Thanks for the help!

My additions as I have owned and rebuilt 2 first gens.

34 Keihin PJ: http://m.ebay.com/itm/HONDA-TRX-ATC-...144?nav=SEARCH

Leave the air box (sand and mud is your enemy). In Uni I trust....
http://m.ebay.com/itm/Honda-ATC-250R...678?nav=SEARCH

Don't forget a UNI oil and cleaning kit


Leave the front suspension. Take your forks off and let onformula1 do his magic on the front and rear. You will have better suspension than a 200x

Also, make friends with Manbearpig as he is probably the most literate of the first gens from my experience.

You probably still have some cracks on your intake boot. Get a newer one and see if that stops your death rev.

[nicker71]

Improper set carb bowl floats have caused me two different first gens to run away like that.

With the simple bolt on mods you'd be suprised just how quick these s can go. They're so de-tuned from the factory and really take to mods well.

[barnett468]

.
a leak down test will tell you if you have an air leak or not . . it might also have a crank seal leak . . below is one of many how to videos.

https://www.youtube.com/watch?v=zdq7NRcUIp8


you might also, back the idle screw way out . . if you can get it to idle below 1,000 rpm, you can spray flammable brake cleaner with the long nozzle, gently around the intake boot etc . . if the rpm goes up, you have a leak.
.