Jetting Reccomendations

[mycat8urskidoo]

Just picked up my first banse, its a 97, havent tore it apart to find out what jets are in it yet, but its definately evident that its not jetted properly. I tried searching to avoid asking this question, but everyone elses shee either had way more stuff done to it, or a little less so i wasnt really sure where to start as a baseline. Heres whats done to it. Bills Pipes, HMF PCII silencers, K and N Pod Filters (2) with no air box (theres a little slush guard type deal there but no actual box), aftermarket reeds, and the head is shaved (not sure how much but the guy runs 110 octane in it) . Not sure if it has an aftermarket timing advance or anything, he didnt really say. Basically just looking for a place to start, ive been reading 300's a good place to start with pipes and no air box lid, but wasnt sure how much more fuel i'll need with a basically open air box and the shaved heads.

[mycat8urskidoo]

Elevations under 1000 ft, main riding temp will be 65 to 75 or so, right now its about 30 degrees which may be part of my problem. Also just did a compression check, 120 psi on both sides, motor was stone cold, and throttle was closed , does this seem pretty low for shaved heads?

[GrMeyer]

I try to do my compression test on a warmed up motor if i can. Turn your gas off and pull the throttle all the way open. Kick that bitch tell the needle stops moving. Just keep both spark plugs out so it kicks over easier. Also, does your compression test have a check valve in the fitting that screws into the head.

 

http://bansheehq.com/forums/index.php?showtopic=70901&view=&hl=compression

 

If you do and the compression is only at 120psi. you are fine with 91-93 pump depending on timing.

 

Read up on this site to help you with understand jetting

 

http://www.dfn.com/benkaren/jetfaq.html

 

As for a starting point.

 

Mains: 320's if your in the 30s and 300 if you in the 60's for a starting point.

Needle: middle clip

Pilot: 27.5

Airscrew: 1-1/2 turns from fully seated.

 

Also you have the tors kit on your bike?

If not then I would really end up buying one. Around $50 and makes jetting 50X easier for jetting.

Also make sure your carbs a synced or you will have some shitty bottom end.

[mycat8urskidoo]

I try to do my compression test on a warmed up motor if i can. Turn your gas off and pull the throttle all the way open. Kick that bitch tell the needle stops moving. Just keep both spark plugs out so it kicks over easier. Also, does your compression test have a check valve in the fitting that screws into the head.

 

http://bansheehq.com/forums/index.php?showtopic=70901&view=&hl=compression

 

 

 

 

I'll have to look at my compression tester, but i believe that im using the Matco tester that is mentioned in that post there. I'm using the shorter of the two i believe, you kind of lost me on the whole compression tester thread haha

 

but anyway, still have the TORS Top, but all the wiring is disconnected, I will be eliminating that shortly, also not sure on the timing, he said something about timing , but i cant remember if he had a 4 degree key or an adjustable plate, or maybe if i was just hearing things. He told me he had head work done at a local shop, and i called them and asked them what kind of compression i'd have if they had done what he said they'd done, and they said 185 fresh, and 150 to 160 when its starting to get weak, the guy at the shop told me theres no way ive only got 120 on his head, but who knows, i may be getting a line of BS From both of them haha. The bike itself runs great, has a few little rough spots here and there but im hoping its just hte jetting, its a bitch to start, but also kind of hoping that its jetting as well. I havent had it out in anything above 30 degrees or so , i'll start to dial her in when it gets warmer. Thanks for the jetting start point, I'm going to go ahead and order probably 300's to 400 jets or so and a couple pilots here shortly.

[GrMeyer]

I dont see really go any higher then around 350 unless you get really cold. You should be fine with just a set of 27.5's in the bike. If it was me. I would try to get the jets from around 270-350's. That is what I have for my set up and I have only gone to 340s out in the dunes at night time due to being cold. If the guy had is porting done, the guy that did it should have a file or what he did to the jugs. If you can get those numbers. The builders on here can really help you in the right direction on what compression should be and what kind of porting the guy did to the jugs. If it was just a shaved head with stock jugs. Then they would need to know how many thos they took off.

 

The only thing I was trying to show you on the compression tester page was what I was talking about with having a check valve in the adapter. Of then the compression has to go all the way up to the tester and you will get a low reading.

[mycat8urskidoo]

I dont see really go any higher then around 350 unless you get really cold. You should be fine with just a set of 27.5's in the bike. If it was me. I would try to get the jets from around 270-350's. That is what I have for my set up and I have only gone to 340s out in the dunes at night time due to being cold. If the guy had is porting done, the guy that did it should have a file or what he did to the jugs. If you can get those numbers. The builders on here can really help you in the right direction on what compression should be and what kind of porting the guy did to the jugs. If it was just a shaved head with stock jugs. Then they would need to know how many thos they took off.

 

The only thing I was trying to show you on the compression tester page was what I was talking about with having a check valve in the adapter. Of then the compression has to go all the way up to the tester and you will get a low reading.

 

 

I just looked at the tester, and it has a check valve at the fitting, then it has about a foot of hose, and a air hose type quick disconnect that connects to another hose which has the actual tester at the top, its a nice kit, came with a couple different short whips with different threads, the total length from cylinder to gauge itself ends up being 3 foot, so maybe between the length, the check valve, and the quick disconnect fitting its reading a tad low. I've checked it for accuracy against a couple other compression testers and they're all pretty close