I wrote my first post about a month ago saying I bought this ’94 sportsman & decided to rebuild most of it. I never had a atv or dirtbike, this is all new to me. So anyway its neatly in a hundred pieces in my garage. My main concern is the ring end gap. Book says up to a .015, I’m reading a .020. It’s a wiesco piston kit. Should this be a concern or is that alright? I’ve bought a lot of aftermarket parts for it, reedcage, 38mm flatslide, & RCR Stage 1 kit. The heads been milled .020 & cylinder has been ported. Just thought of something else. I didn’t have anything done to the squish band, how is this going to effect the engine? Bottom-end is being rebuilt with all new parts. I have a lot of money in the engine alone & want to take every precaution not to f it all up & want to avoid having to doing it over. When it gets all put back together how do I start to tune this thing, meaning should I put it back together with the stock parts, or just put it together w/ the all the aftermarket stuff & see what happens? The 38mm flatslide is used but will be getting a good cleaning once I get my new jets from Rick. Also when I go to put the clutches back on how far should the drive clutch slide on that shaft, or do I really need that alignment tool? What about oil for the break-in, I already got the polaris blue but may go to amsoil, is one better than the other for breaking it in? I’m removing the oil injection & will be mixing. Anything else of importance I should remember besides the keep it clean, take it easy on the first tank stuff? Theres lots of different questions in here, help me out w/ what you can. Thanks for all your help. Justin…

You guys don’t know how excited I am, I can’t wait to start it up..

 

I'm going from memory here but check with rick or someone knowledgable because when I hopped up my Xplorer, I specifically remember the gap as being different from the Polaris stock specs when using a Wisco. Can't remember if it was more or less but it was different.

 

There should be a piece of paper in the box with the piston,it should have the clearance on it.I have seen where alot of people have had a bad lean spot with the 38 flatslide in the mid range ,so be careful.Another thing to keep an eye on is the counterbalance oil.Check it very often for water invasion from the water pump seals,this alone could save you a bunch of money.Break it in with the old blue oil and you should be ok with the Amsoil if you wish to change later.If you can get your hands on a 39 PWK from Rick,i would highly suggest that you get it.These motors run very strong and with no lean spots with this carb.Just do some plug checks when you get it going again.Hope this helps.

 

Thanks Snow & CED for the help. I looked at the paper again from wiseco & in bold it just says 'IMPORTANT: Always check the rings for proper end gap'. Maybe I'll call rick tomorrow & ask if my kit got sent out yet & about the end gap, & squish band not getting done. I had a feeling about using the polaris oil first. You got me worried about this carb now. What to do.. Any other suggestions?

 

See what Rick say's about the carb,he may be able to get you close to where it needs to be.Good luck.

 

I guess I'll find this out when I call a little later but how much does that 39pwk go for?

 

I believe they list for around $230.

 

i have a highly modified 95 400 xplorer with the 38mm TMX flatside carb and i have not had any problems. i have set mine up to be just a little bit rich and have different air settings for the winter and summer. i have a 390 main and a 35 pilot jet with usually 1.5 turns out on the air screw. i run premium gas with a 44:1 mixture of Klotz Supertech(red label). i trail ride and flat track race some in the summer in western ky. To fine tune the carb air setting i will find a night that it is cool and then do plug checks. if i can help just email me
later
hunt

 

Well I just got off the phone with Rick. He basically said the ring end gap should be larger than stock. I told him the manual's limit was .015, & I was measuring about a .020-.022. He said that it's probably a little on the tight side, but should be fine. He said some formula like for every mm the cylinder is bored you want another 10 thou to the ring end gap; something like that. My other question had to do w/ the squish band not being touched while the engines been ported & head milled 20 thou. He also said that wont cause any problems what-so-ever. I talked to him about the carb situation, he said on the '94's the 39 pwk is a tight fit, but like everyone else on here said it's awesome. He said I could just bore out the stock so it would fit real well & I would get performance inbetween the stock & the 39pwk. I checked Ebay out before calling him & found that they were basically starting about $190. It was $250 from Rick & thats brand new w/ a couple different parts for it for our rides. I've been working my *** off & gots me some over time the last couple weeks so I decided to go for it. So I'm pretty excited now with all these worries out of my head. Thanks to all with the help & suggestions. I think I'll be hanging around here more often..