Main jet size issues, help?

[yagermeister_07]

I am doing a rebuild from the bottom up. I am new to this and it's my first banshee. I have made it all the way to the carbs. on putting everything back together. Heres the thing, do i need a bigger main jet if I have aftermarket exaust? The main jet that is in there now is 200. Help please I'm lost..... Thanks.

[Larry's Shee]

YES !!

 

List your complete set-up, elevation, temp and someone will help you further.

 

Welcome to BHQ !!

[yagermeister_07]

Thanks, here we go

 

1. Exhaust: toomey T-3's with FMF silencers

2. air filter type: K&N

3. type of air box: no air box

4. elevation: 590 feet

5. pilot jet: stock

6. main jet: stock /200

7. temperature: 55-90

8. port job: no

9. carbs: stock

10.carb size: stock

 

is there anything els that is needed for info?

[figuare9]

Thanks, here we go

 

1. Exhaust: toomey T-3's with FMF silencers

2. air filter type: K&N

3. type of air box: no air box

4. elevation: 590 feet

5. pilot jet: stock

6. main jet: stock /200

7. temperature: 55-90

8. port job: no

9. carbs: stock

10.carb size: stock

 

is there anything els that is needed for info?

 

 

When I got my FMF SST's they sent me a 300 main. You're definitely too low. I would try going up to a 27.5 pilot, and a 270-300 main. Search on here how to do a plug chop to dial it in from there, but that might be a better start for you. Hard to give you an exact idea, as I'm 1500ft, with a closed airbox with way different mods. I'm actually going to post another topic about getting my shee jetted right as well. Good luck to you!

[yagermeister_07]

thanks, i just bought it from a guy at work and knew almost nothing about it other than it had a bad "piston" is what i was told. i took it all apart to find out that i needed a whole new crank it had a bad rod bearing. luckly i found a good crank on CL for $50 i think that was a good deal.

[06specialedition]

Start big on the mains and work your way down from there. Better to be too rich, then lean that motor out.

[yagermeister_07]

Thanks for all the advice I have been going nuts over this all day lol. but at least i know that if i start off big and work my way down i wont burn it up. And is it necessary to do a leak down test?

[figuare9]

You better be damn well sure that crank isn't bad. Check the gaps, slack, etc. Per clymer manual. Or have it looked at. 50 dollar crank sounds like bullshit to me. Also, yes. The safest way to put that motor together is by doing a leakdown test. Make damn well sure to use a good sealant, Yamabond 4 or the red hightemp silicone works best. Be sure to replace all seals.

[yagermeister_07]

You better be damn well sure that crank isn't bad. Check the gaps, slack, etc. Per clymer manual. Or have it looked at. 50 dollar crank sounds like bullshit to me. Also, yes. The safest way to put that motor together is by doing a leakdown test. Make damn well sure to use a good sealant, Yamabond 4 or the red hightemp silicone works best. Be sure to replace all seals.

 

 

 

 

I checked the crank good, all the gaps and slack were all in spec. as refering to my clymer. the guy i got it from originally had it on there for $175 but i got it for $50 because he forgot how much he had it on CL for. He changed it out because he put a long rod in both of his banshee's. He had two cranks but i only bought one. I have replaced all seals and gaskits, and use yamabond 4 on the case. thanks for the advice