I will be finishing my polaris rebuild tonight, just have to put the recoil cover on and button upo the top end.
I picked up a 260 and 250 mikuni main jet with the purpose of running the motor fat at break in since I do not have oil injection any suggestions as to what ratio to use?

I had my head decked .020 do I need to run a richer main jet as a result of this? Also has anyone used a power jet? Bubba you may be able to give some feed back here. I have seen you mention them in the past.

lastly my local dealer is a friend of mine and has a hpd 40-38-36 helix he is not using and will sell to me for $20.00 with my mods is there any point in going to this helix? he is recomending the polaris gold or blue spring as well. If youwere me would you pick this helix up? Or considering I have no pipe and don't really plan to get one is it unneeded? Bubba I could use your help here as well.

I have a tacometer installed two so I can use that for tuning.

Mods.
polaris yellow primary.
open element uni.
straight through silencer( looks like hpd's)
12 to 1 compression.
0.20 wiseco piston.
V-force 2 reeds.
50 pounds of removed weight
12 tooth front sproket.

 

Hey Conig, raising compression doesnt require more jet, only more octane if needed. You will be fine on pump gas, but make sure to run the premium (92 or 93). The best oil/gas mix IMO is 32:1 or 4oz to a gallon. Going up on the jetting is a good idea when removing the injection system. The oil will displace a little of the gas and make the air/fuel ratio a little leaner. Not anything to speak of, but if a person was right on the verge of burning one up then changed it around he might just cross the line.

the 40-38-36 would be great for a trail mod or if you were going to run a pipe that turned more rpms. For a stock pipe I would personally save the money on the helix and get the violet HPD secondary spring or the Aaen blue secondary. That will greatly help with backshift and help hold a lower gear ratio longer for slower trails. They make an incredible difference. Dont get the gold for the 400, they are better for the 250's.

A powerjet in the carb can be a great addition. They give the opportunity to achieve a range of around 5 main jets and can help tune for altitude or temp changes. The drawback to them are that they only work above 1/2 throttle, and mainly above 3/4 to wide open. if the weather or altitude changes too much then it could still burn up at part throttle, or where a lot of people ride at. The best thing I always recommend is to get a flatslide 34-36mm carb, either a mikuni TM or a PWK keihin. They have awesome throttle response and are better in the midrange than the stock 34mm roundslide.

By the way, no matter what mods you do to the machine, as long as your running the stock pipe you need to have the top rpms around 5700-5900 to make the most power you can. Any more rpms and your starting to fall off the peak power.

Hope this helps,Bubba

 

what do you think of the polaris blue secondary? I can get this for a pack of cigarettes.


thanks bubba I figured that would be the case on the helix. I have a feeling im turning two many rpm's, thats why I bought a tachometer to try and tune it. I'm going to try some different primary springs in the future so I can vary them to different trails etc.

I bought a 260 main jet to use for break in so I should be covered there. my motor builder told me to run the mixture as 20-1 for the first 1/2 a tank and not to get on the throttle much. didn;t think I needed to rejet for a compression change just wanted to be sure.

I thought about getting a flat slide there not that expensive just didn;t know if it would be worth it.

 

I dont have the specs on the Plaris blue, and they aren't listed in my book. The two I mentioned are very well known and work great. Dont buy or trade for it unless you really know what your getting.

To keep the top rpms in check with the stock pipe you need to stay below 150lbs on top pressure. The green is slightly more than the stock white. If you like a good holeshot or hard takeoffs then go with the purple. It will engage higher but still be correct on top end. The yellow is 176lbs on top and that is too much.

A flatslide will outperform a roundslide carb. They also make greater bottom end power and response in comparison.

 

I have an EPI orange stashed in the shed. 79 at engagement 140 on shift out. I was thinking of trying an epi yellow 95 engagement 145 shift out for situations that don't need tons of traction.

 

found this on aaen's website.

Aaen Blue 308 Torsion Rate
in.-lbs./rev

Polaris Blue 312 Torsion Rate
in.-lbs./rev

if you want to add this to your records, they seem about the same.

 

HPD doesnt state what the torsional rate is for the violet, but they do say that the polaris blue has an aggressive backshift. The violet must not be as stiff as the blue.

The epi orange or violet sounds like it would be a good choice to stay in the boundaries that you want

 

cool, thanks for your all your help.

you wouldn;t happen to know the size and thread count of the cylinder nuts do you? I managed to loose mine in disassembly and can' t finish putting my motor back together until I get the cylinder held down.

 

They are either going to be a 10mm X 1.5mm thread, or a 10mm X 1.25mm thread. I think the 1.25mm pitch should be right, but I am not 100% sure on that.