polanda build questions

[slamdak8782]

I bought a polaris 400l cylinder for a polanda build. Does anybody know what would be the best way to port it to run good on the 250r. To me it looks like the boost port ceiling angle needs to be raised along with the normal blending of sharp casting marks. What areas are the problem spots in this build. Please hold comments of just buy esr. I'm going to do this for fun so I'm not concerned with the easy route stuff iknow how to do that I'm wanting something unique to inform myself and others on the site how this is done.

[slamdak8782]

This thread will focus on the steps required to complete a polanda build I hope to make this comprehesive so that others can attemp this step by step. There will be pictures uploaded as. The build progresses. So can I get some help from those in the know. I also am in need of a 250r bottom end because I don't want to trash my already nicely set up 265. Does anyone have on e for a reasonable price

[Pumashine]

Originally posted by slamdak8782
I What areas are the problem spots in this build.I'm wanting something unique to inform myself and others on the site how this is done.
I have is a pic of the finished cylinder. You can see where the builder drilled a 1/2" hole and ported it for the intakes.

http://i27.tinypic.com/who3cw.jpg

From the inside

http://i31.tinypic.com/1232ogk.jpg

Heres what it looks like after its done. I do not reccomend putting the water outlet out the side to hit your pipe. It would be better to go out the back over the intake.
http://i28.tinypic.com/6emzc8.jpg

Installed on the 87


http://i26.tinypic.com/314fp6c.jpg

[slamdak8782]

how does it run?

[slamdak8782]

Here are some pics of the stock 400l cylinderhttp://21.52.17

[slamdak8782]

from the side

[slamdak8782]

intake

[slamdak8782]

exhaust

[slamdak8782]

What rod is needed to make this work?

[86honda250]

My cousen has a 427 polanda. It runs about a bike length faster then my 350. But his build is alot milder then mine.
esr 350 reported buy K&T racing
trx 9 pipe, race gas dome runing 111vp
cr ignition, v fource 3 reeds, 39pwk bored to the max

427 polanda with lots of porting
FTZpipe, V fource reed with the intake bough not build vary nice
he runs 87 octange, 39 pj carb, stock ignition

That polanda runs well and its got lots left in it were my 350 is about all your going to get unless you go to a full on drag buld.

[slamdak8782]

Can you ask him what kind of rod he has and if I need to balance the crank

[Pumashine]

Originally posted by slamdak8782
Can you ask him what kind of rod he has and if I need to balance the crank

If you are runiing a 82mm or smaller piston you will not have to bakance the crank. Most are using the KTM rod which is almost the same length as a stock 250r rod. Hotrod part# CK111 if I remeber correctly? You can go onto the hotrod site and look up the exact part number by giving the rod legth of 130mm? Its been awhile since I have done the Polonda thing. They are just not as dependable as a Puma cylinder. No coolant leaks or spacer plate leaks and all the epoxy you have to use to glue all the stuff together.

[86honda250]

he is using the stock honda long rod with a 87mm piston. The crank is not balanced. He hasent had a problem yet but there is not a lot of time on this engine yet.

[slamdak8782]

Thanks for the responses I appreciate your help

[slamdak8782]

Puma shine how did yours run after the port work.

[slamdak8782]

Piston Choices

1. Stock Polaris 400l 83mm and other sizes
2. YZ490 89mm
3. AAEn 91mm?

Good Pipes for this

1. TRX 5
2. FTZ fat in frame for "Top end"

Carbs

38mm TMX Flatside Carb
39mm Kiehan PWK Airstryker
42mm TMX Flatside Carb "BIG BORE"

Rods

1. Modified yz250
2. Stock 250r 130.3mm or 125.3mm
3. Hot rods cranks assembly part # 4007 250r
4. Hot rods stroker crank assembly part# 4107 2mm stroker 250r
5. KTM 8111 hot rod (thanks methyman)
6. 250r hotrod 8109 rod only

Bore/Stroke

72mm X 83-91mm

Displacement

1. 389-490

[slamdak8782]

Ok so I looked on the wiseco site and it doesnt look like the Polaris piston is a straight bolt on part. Also the KTM rod does not appear that it will fit according to the specs given on hot rods.

Also I noticed in the pic from pumashine that there was a piece of the intake bridge cut out is that ok to do or will I run into reliability issues with that?

[slamdak8782]

measured cyinder at 82.93 bore so it looks like a 83.25 piston is needed

[methyman]

KTM Rod 8111 specs

Big end bearing (mm): 24x31x17
Big-end bore (mm): 31.00
Big end width (mm): 16.90
Center to center (mm): 132.00
Pin diameter (mm): 24.00
Pin length (mm): 59.90
Small end bearing (mm): 18x22x20
Small-end bore (mm): 22.00
Small-end width (mm): 16.90
Washer thickness (mm): 1.00

TRX250R 8109 Specs

Big end bearing (mm): 24x31x17
Big-end bore (mm): 31.00
Big end width (mm): 16.90
Center to center (mm): 130.30
Pin diameter (mm): 24.00
Pin length (mm): 59.60
Small end bearing (mm): 18x22x22
Small-end bore (mm): 22.00
Small-end width (mm): 16.90
Washer thickness (mm): 1.20

The Polaris 400 piston will work because that is what the Puma Cylinder uses with a longer wrist pin bearing.

[methyman]

Information found on Hot Rods web sight.

http://www.hotrodsproducts.com/index.cfm

[slamdak8782]

Great info I found that very helpful I couldnt find it on there. The KTM rod 8111 hot rod is found on the following models:


1990-1999 KTM 250
1990-1999 KTM 250 EXC
1990-1999 KTM 250 XC
1990-1999 KTM 250 XC-W
1990-2003 KTM 300
1990-2003 KTM 300 EXC
1990-2003 KTM 300 MXC
1990-2003 KTM 300 XC
1990-2003 KTM 300 XC-W

[Pumashine]

Originally posted by methyman
KTM Rod 8111
The Polaris 400 piston will work because that is what the Puma Cylinder uses with a longer wrist pin bearing.

Thanks for the info Mathew. You will want to use the KTM rod 8111. It is bigger in the cross sectional view than the honda rod. Thus making it stonger. And note the longer wrist pin bearing. If you don't get one of these bearings you will need to put in 2 spacers .080"-.100" to take up the slop. Otherwisr the wrist pin bearing will explode.

The porting on my polonda was set up as drag even though I told Dave Moore to set it up for duning. The drag builders are always doing what they would personally do. Most of those guys are out of business. With the correct port work I believe you will be very happy.

Now the bad part. Cutting and redirecting water and exhaust. The cylinder had alot of epoxy filling everywhere. Next the spacer plate will leak. Its hard to tune when your leaking air in and out the bottom end.

There are two different cylinders . One has the intake at an angle like the 250r. The other is straight up and down. You have not posted any pics yet so we can't see what your working with.

[slamdak8782]

I posted pics of the cylinder yesterday. All different views. We have some amazing glue from work that we use to bond magnets to the rotor on electric motors. Im going to glue the spacer on. Im pretty sure it wont leak because Ive seen this stuff hold up to 5500 RPM on a flat surface. Its amazing stuff. Ill have to look and see what it is called tomorrow.

[Pumashine]

Originally posted by slamdak8782
I posted pics of the cylinder yesterday.

Sorry I was busy all weekend. I think you were talking about the bridge on the outside over the intake? Leave it there if you can. He only took it out because he said it was in the way? Of what?
I wanted to be able to hook the head stay uo to that bracket.
Definately use your bonding agent. Looks like you are on the right track. Keep us updated!

[slamdak8782]

Actually pumashine I was referring to the intake itself there is a cross. Do you see the steel in the liner covering the intake passage towards the top? On yours it is gone. I think it is there for torque reasons. Possibly increasing velocity?

[slamdak8782]

Does anybody else have a good picture of the porting. I hogged mine out with the 1/2 drill bit. The drill kept trying to break my arm but I got it through. Worked a little on smoothing the casting edges. I need some advice on the porting.

[Pumashine]

Originally posted by slamdak8782
Actually pumashine I was referring to the intake itself there is a cross.

Yes, you have the later model cylinder. Kinda like the difference between the 86 and 87. It is there for the better. The bridge gives more support to the piston.

After getting my 408 puma cylinder together I believe porting is over rated. The engineers designing these cylinders are not stupid. With no porting whatsoever these cylinders pull like a jeep hauling the mail. The hole you drilled makes about 80% of the difference. Just take out the ruff edges and copy any professionalls ported cylinder for the best results. Too much porting has been the biggest mistake of all first time builders IMO.

[slamdak8782]

Ok well Im really working on this thing got some new pics. Here are some little pieces I made to mount up the cylinder and to add some strength to the cylinder

[slamdak8782]

Here is the top of the cyinder I wacked off the water outle and Im going to weld it in and then install a fitting so that I can get the water out where the temp sensor was.

[slamdak8782]

Here is a pic of the porting i did it is still rough im going to bead blast it to make sure it is relatively smooth. I try not to knife blade anything but the boost ports are difficult to smooth. I tapered the inlet on the intake to make it flow a little better removed the really rough casting areas and hogged it out with a 1/2 inch bit as suggested. It seemed to work pretty good but it kept trying to jump off of the table. Now I need to figure how to get the spacer plate.

[slamdak8782]

Here is a picture of the water inlet orientation im going to try and use. We'll see if some flexible hose from summit will do the trick. It is steel braided and looks nice so, I'll post part numbers when I find the right stuff if it works out. It looks like it will.

[slamdak8782]

Does anybody know how to get a spacer plate for this build? I plan on using the ktm rod.

[Pumashine]

Are you going to move your cylinder studs to get the cylinder to fit the 250r bottom. I can cut you a spacer but need to know which stud pattern you are going to use.

[woodsracer144]

holy balls! your really jumping on porting... What about the new bolt patteren? I was doing one of these builds as well but it kinda got put on hold, If you dont mind, I'll post some pics, I use the honda studs and moved it on the cylinder, Mine doesnt look very nice IMO but oh well, work in progress...

This is the first real day i started on stuff, those front to lobes were broke off as well so I really went to town...

[woodsracer144]

and heres a pic with it on the cases. I still have to mill my cases out and then get a trans and most of that stuff for it, I have my piston for it though, STD bore.

[slamdak8782]

Pumashine I am going to be using the honda bolt pattern to bolt the jug on. Thanks for letting me know Im not sure how thick it needs to be im going to use the KTM rod if that helps on the thickness of it. Thanks for contributing woodsracer.

[woodsracer144]

What piston are you useing? cause i have a stock polaris one and the skirts in the crank shaft...

[slamdak8782]

well I think Im going to have to use an oversize 83.25 or maybe 84

[Pumashine]

Originally posted by slamdak8782
Pumashine I am going to be using the honda bolt pattern to bolt the jug on. Thanks for letting me know Im not sure how thick it needs to be im going to use the KTM rod if that helps on the thickness of it.

Mine had a 3/8 spacer with the 132mm KTM rod. But some guys use 1/4" spacer. Once you get everything set into place you can use some shims to find out what spacer you need. Let me know and I will get it cut the same week.

[woodsracer144]

do you have a pick of your cases milled out?

[slamdak8782]

i dont have the cases milled yet.

[slamdak8782]

Ok well after doing a bunch of fabricating to get the little pieces cut for the jug. I had a buddy of mine take it to work, hes gonna weld and fill the holes so that I can redrill the holes to honda size. Now Im not sure exactly what rod to run. I was thinking the KTM rod but im not sure if that or the yz490 rod would be better. Does anybody know what piston I need to run in this thing or what all needs to be done to the rod in order to make it fit right.

I'll be getting the jug matched to the cylinder studs soon and I'll put some pics on then of the issues that Im having.

[woodsracer144]

I would run a pro x polaris piston. as far as rods im not sure..

[Pumashine]

Originally posted by slamdak8782
Now Im not sure exactly what rod to run. I was thinking the KTM rod but im not sure if that or the yz490 rod would be better. Does anybody know what piston I need to run in this thing or what all needs to be done to the rod in order to make it fit right.



The KTM rod works fine. The YZ490 rod takes alot of machine work to make it fit. The Wiseco Polaris 400 pistons are pretty cheap and have the polaris windows already cut in them.

[slamdak8782]

So I opened pandoras box. Ok well its not that bad. Anyways I got a bottom end for the polanda build had some progress this week I hope i can put it back togethor

[slamdak8782]

hmm opened it this way

[slamdak8782]

Rusty pump

[slamdak8782]

the moment Ive been waiting for

[slamdak8782]

progress thus far after a lot of elbow grease not as shiny as pumashine but my first sucessfull polishing

[slamdak8782]

little closer

[slamdak8782]

Battlescars. Shift lever

[slamdak8782]

more old damage hall sensor. I read over at trx250r.net that this was a very common issue on Rs.

[slamdak8782]

scar

[Pumashine]

Oh geeze, the bottom end is looking bad. The break in the cases at the shift shaft is going to be hard to fix. All those fixes usually end up leaking. Welding and machining will fix but cost some $$$. If you want your covers touched up just give me a holler.

Its great to see guys put so much effort into building a strong R!
I've heard they make real good power done correctly.

[slamdak8782]

Yeah that is my main worry with that case. It was repaired in the past. but there is evidence that the shaft obloned the hole a bit. Im thinking of installing a shim in there to correct the misalignment. I have a lot to do to it for sure but Im having fun. Transmission looked really good. Its in a million pieces now.

[slamdak8782]

Pumashine the longer bearing I need. Is this the ktm or the polaris wrist pin bearing? Do you know what P/n thanks

[croat1]

hey slamdak8782: did you get the shift lever area repaired. if you did can you post a pic of the repair. i'm in ther same sitaution with a 88 motor i have. it was repaired before but it still leaks. pm me the name of who repaired it/is going to repair it.
i'm just south of cleveland.

thanks
joe

Last year the case pictured below had a cracked shifter bore similar to the one you posted. It now has been repaired, does not leak, you can see a slight nit line in the bore at the point the sleeve is pressed in at, can not see it once the shift lever is in place...

The shifter bore was bored out and an insert plug press fit and welded, then it was rebored to the OEM shift bore diameter, not cheap, however; works great and saved the left case. Call the BDT Motorsports @ 909-802-6516 they are in SoCal

[slamdak8782]

I think im going to have dave moore racing repair the shifter on mine and also due the case boring for the polaris top end

[Pumashine]

Originally posted by slamdak8782
I think im going to have dave moore racing repair the shifter on mine and also due the case boring for the polaris top end

You picked the right guy for the job. Dave built both my polonda's and knows what he is doing when it comes to this. He was the originator of the polonda in my book. He has the most knoledge since he has built dozens of them. He also has blueprint for the spacer plate.

Looks like your on your own from here forward. Good luck!

[slamdak8782]

Hey Pumashine I still want to get the spacer from you. You said you did the KTM rod with yours and that is what im going to do so I want to get one of those from you if your still interested

[Pumashine]

Dave Moore built my polondas and the spacers were included. He's been building 250r stuff since he could ride. Knows all the in and outs on the conversion. The pics I have are a couple years old. Sold the polondas and moved onto the Puma's. Never could get the spacer plate to stop leaking. Be sure to use some sealant.

I heard the conversion never got aff the ground becasue the horsepower they made was less than expected. Its a Polaris not a Honda. Good cylinders use engineering simplicity for good results.

The puma cylinder in the box will make more horsepower than a ported polonda. I took the stock stroke 408cc puma cylinder cleaned up the flashing and sent in for plating myself. Once installed the bike walked all over the polonda I was riding. Going up the dunes I would look behind me and the sons front end would come off the ground and he would wheelie past the polonda with his puma. The grin on his face could not be wiped off.

Polonda
http://i37.tinypic.com/k9c3nc.jpg

Puma
http://i36.tinypic.com/353aa0z.jpg

[genoapb]

You can give cometic a call and they will be able to make a spacer for you, no problem. When I built a polonda that is what I did. Just tell them what your doing, you need a honda base bolt pattern and the polaris outside shape and whatever thickness you need. But they will only go up to .500" thick.

I also had problems getting the base gaskets to stop leaking or actually blowing out from the case pressure and the remedy to that was I dimpled the spacer on both sides and used cometics metal gaskets with a viton coating and no more blow outs. I dont believe the gaskets cost any more than normal ones either!

[slamdak8782]

That is good info did you take any pictures of that? I like to get a clearer picture in my head of that

[slamdak8782]

Been doing alot to the polanda check out the progress

[slamdak8782]

heres one of the other side finally got it to fit

[slamdak8782]

Here is a picture of the shifter fix. A borze bushing cut to fit from a guy from work. Its nice to have talented friends I designed it a little tight threw som jb weld in and knocked it in with a hammer after a little dremel work 320 600 and 1000 sandpaper fits like a glove.

[slamdak8782]

Well I got the cases cut after about four hours of hard work and some deliberating. The head studs reall were hard to get out. I finally sprayed some pb blaster in there and put two nuts on it then heated with mapp gas and pulled at the same time slowly broke loose on all four wasnt bad after figuring that out. I still have a lot of port matching and filling to do with some devcon but feeling pretty good about it

[Pumashine]

Originally posted by slamdak8782
Here is a picture of the shifter fix.

That fixes the shift shaft alignment. But where the seal is pressed in will leak if you dont fix the crack. Just a heads up on case repair. Most weld up the crack and bore a hole for a sleeve to slide in. Then put in a new seal.

You are doing a heck of a job on this one. I have to praise your work because thats what got us big bores today. Single efforts to make a big bore come alive. Keep up the good work. If it were not for people like you Calvin would have never built the Puma.

[slamdak8782]

The cracks are epoxied in the rear and I'm not sure if it leaked before but if it does back to the drawing board. Thanks for the compliment. I hope this becomes a sticky someday when I'm done. I figured why not show people what all is involved. I'm going to try a rotax when this is done. This will go in my build the legenadery 250r build up when I'm done. The rotax is going to be a all out big as can be done stroker on a white blue r. One will be cross country all stock parts converted and this one will be on the red one for motocross even though I don't jump much I like the plush suspension.

[slamdak8782]

I ordered some longer head studs and acorn nuts to bolt the cylinder down. Cant seem to get a hold of Dave Moore he must not be checking his email. I need a spacer to get this thing lined up better. Im gonna fill the holes on the head and redrill them

[Pumashine]

Originally posted by slamdak8782
I need a spacer to get this thing lined up better. Im gonna fill the holes on the head and redrill them

Have you figured out what spacer you need? I will cut you one that is close. Will have the same shape at the bottom but I'm not sure about where the cylinder meets the spacer. Let me know what thickness is needed and I will get you one pretty quick.

[slamdak8782]

If you cut it 3/8 with a little extra meat on the outside that way I can cut back what I dont need. If you cut it like the stock ports on the inside like the 250r then I port match it to the polaris top. That would be great. Should be alot closer with that couple hours of dremel work it will fit like a glove.

[Pumashine]

Originally posted by slamdak8782
If you cut it 3/8 with a little extra meat on the outside that way I can cut back what I dont need. If you cut it like the stock ports on the inside like the 250r then I port match it to the polaris top.

Yeah, I forgot I have the cylinder for matching. You are using the stock Honda base right?

[slamdak8782]

yes stock 250r base. thanks

[Pumashine]

I made a prototype from scrap material. What size clearance holes do you want on the spacer plate? Here a pic in the motor.
http://i51.tinypic.com/e6sjnl.jpg

And one on the cylinder. The holes are now stock honda gasket size. But will make them whatever size you need to get it to fit on the 3/8" spacer.

http://i54.tinypic.com/2qnz23o.jpg

[slamdak8782]

go ahead and make them ten 10mm that is what I am going to use. So that should work great thank you. Do you think you could clearance the holes for the boost ports on the polanda? Send me a pm for the price. Thanks

[Pumashine]

Originally posted by slamdak8782
go ahead and make them ten 10mm that is what I am going to use. So that should work great thank you. Do you think you could clearance the holes for the boost ports on the polanda? Send me a pm for the price. Thanks

Sorry, I don't do any motor work. Cut your 3/8 spacer today. The 10 mm holes are real tight and do not slide on my bottom end. I think my studs are bent. Just letting you know you may have to drill them out a hair. Other than that it fits like a glove on the polaris top end.

http://i53.tinypic.com/2m7yn0p.jpg

[slamdak8782]

Awesomeness as usual from the chisel and hammer specialist!! :devil: Yeah getting this thing lined up has been a challenge still working on that. After that it is onward to the exhaust issue. I ported the transfers a massive amount to be a a little more similar to what the 250rs intake looks like. I think this project is a bit of a pain in the rear. I will finish it but I dont think i'd build another one. A alot of cutting and what not to get it all togethor but after its all done maybe I'll change my mind.

Pumashine may have a shiny hammer & sharp chisel, however; the work on that spacer plate was done on a much more accurate mill…

Looks good!

Carlos.
:)

[Ruf Racing]

Originally posted by acecarlos
[B]
Looks good!

/B]

Now that's how you should post comments, :D Ace!

[slamdak8782]

Hey Pumashine I sent you a picture of what i needed. Here is what the spacer needs

[Pumashine]

Originally posted by slamdak8782
Hey Pumashine I sent you a picture of what i needed. Here is what the spacer needs

Looks pretty easy, you don't need to send the spacer back. I have a cylinder to go off of. The cylinder I was using was cut for the 250r bottom end. Yours will match the polaris cylinder. Not a problem.

[woodsracer144]

hey sorry its been a long time since i've been on here. you choose a rod yet?

I've had too many projects going on right now so this has been kind of been put hold for a little while.

puma how much you charge for those spacer plates?

[slamdak8782]

Ok so here is the final on the case milling now I need to fill it with JB Weld. Im going to use some styrofoam cut it out to my fill dimension and fill er up. Oh yeah my mill was a dremel and a sharp chisel and im not joking about that either

[slamdak8782]

Getting there

[Pumashine]

I followed Tom's directions for the new 3/8" spacer plate from the pics above. I put it on a polaris 400 cylinder and this is the final part. Took 2 hours and 4 tries before this one fit perfect. Top view

http://i51.tinypic.com/2vi5a2o.jpg

Front and back. Had to fill in one side and cut out the other.

http://i52.tinypic.com/r1y16s.jpg

http://i52.tinypic.com/wi4ox0.jpg

[slamdak8782]

Umm how much you gonna charge me for that? Im worried now. Actually, Im not but Thanks Pumasine you the man. Are you gonna sell those now.

[Pumashine]

Originally posted by slamdak8782
Umm how much you gonna charge me for that? Im worried now. Actually, Im not but Thanks Pumasine you the man. Are you gonna sell those now.

I am not here to make money off of unsuspecting 250 enthusiasts. I cannot say I will sell these now. But if another guy wants to build a Polonda I will be happy to cut him a spacer plate. The more 250R's there is, the better this world is. You gotta love this hobby to survive.

My chisel is getting dull and my hammer is still shiny.

[slamdak8782]

I know if I had this done by someone else it would cost me alot more. Thanks for your help.

[Pumashine]

Originally posted by slamdak8782
I know if I had this done by someone else it would cost me alot more. Thanks for your help.

Hey Tom your mailbox is full. I am sending you the spacer and a tree ornament today. Merry Christmas !!!!!!!

[slamdak8782]

Well I got the spacer and ornament today. Spacer fits awesome, That ornament is too cool for a tree that sucker is getting pop riveted to the quad somewhere.

[woodsracer144]

not to high jack but what freaking rod do i need to use? i thought i could use a stock Honda 250r rod but that is a big negative for this guy! I picked up a oe polaris piston and i cant rotate it the full 360* i pull about 280 from when the skirt of the piston hits the crank.


is your running yet?

[woodsracer144]

not to high jack but what freaking rod do i need to use? i thought i could use a stock Honda 250r rod but that is a big negative for this guy! I picked up a oe polaris piston and i cant rotate it the full 360* i pull about 280 from when the skirt of the piston hits the crank.


is your running yet?

[slamdak8782]

Well from what I have read you can use a stock rod. But a lot of people use the hotrods ck111 ktm250 rod. Mine is not done yet havent got the exhaust flange piece, and Im taking a break from it I will finish it though. Maybe it has to do with the year of rod that you are using. There is a long and a short one i forget which years. Definitely need a longer rod from what you are saying.

[slamdak8782]

I can confirm that the ktm rod 8111 hotrod does indeed fit to the polaris piston for the 400l.

It was stated in this thread earlier that I would need a different wrist pin bearing or spacers to make this work. What is it that I need spacers or larger bearing on the wrist pin? Can anyone comment on this issue? Thanks

Getting closer to bolting this thing all back togethor

[WeTDrEaM]

What do think the total cost is about to do this build to a stock 86 250R?:confused:

[slamdak8782]

My personal opinion is that I wouldnt do this again. It is much to time consuming and there are cheaper and more reliable options out there. Also I saw a guy who made a rotax motor fit which in my opinion looks a lot better than any Polanda. It also has a more modern port layout and there is entirely too much cutting involved on the cases. Lastly I don't really like the idea of a lowly polaris touching such a Legen as the 250r. To answer your question as to price this is ballpark figures now too so. But here goes

piston 100
rod 120
Not sure on how much getting the rod pressed on costs yet but guessing 200
Then there is balancing which IMO with such a large piston and everything should be done.
guessing 200
Then there is a spacer issue on the wrist pin dont know guess 40

The exaust flange issue say 100

bearing kit for bottom end 100

seal kit 100

assembly 100

hardware 50.

So I guess ballpark 1000 plus bottom end cost

So it could range between 1500 to 3500 depending on how good you are willing to make it.


If you were a machinist It could be done for much less otherwise its a pain in the butt.

So I say buy an ESR or a puma and be done with it unless you are up for a lot of headaches.

[woodsracer144]

You can do it cheaper, im just using a long rod and spacer plater, OE piston and had a guy just turn some mild steel that will be pc'd black and made a flange I know when im done i'll be under 300

[slamdak8782]

Yes it can be done cheaper. It all depends on how many corners you want to cut. But woodsracer is right. It can also be one of those projects that draws you in and sucks your wallet empty :D

[slamdak8782]

Woodsracer can you post a picture of your flange when its done?