Just picked up a shee had a few ?'s about the mods....

[25THZ28]

I just picked up my first Banshee yesterday. It's a 2004 Limited with Toomey T6 pipes. stage 4 head and the single carb and intake kit on it. The guy mentioned a while back about it having a 420 big bore kit in it, but I forgot to ask him more about it. I was going to take the head off and look at the cylinders, but is there a quick way of checking to make sure if it's got the kit or not? I'm sure I can measure the bore size, but is the stroke different?

 

I also had a question about vibration. How much do these vibrate? This one seems to vibrate more than what I would think is normal. I was contemplating taking the crank out to have it trued, what do you guys think?

 

Is the single carb intake kit really the way to go? I'm sure it's easier to tune, but does it add a decent amount of power? Does anyone else have this kit on theirs? If so what's your set up, jetting, air screw ect?

 

With the stage 4 head, what should the compresion be? Are you suppose to run a different plug or stick with the stock one? What is the standard plug for these? Also what is the mixing ratio? Most of the two strokes I've had were 32:1, the guy said it was 40:1.

 

Is there anyplace to download a service manual for this?

 

Is there anything I should do or look out for, other than the general maintenance items?

 

I appreciate all the help,

 

Thanks,

Zach

[25THZ28]

Found the service manual.

[lowbuckracing]

If it is a 420 then the carb set up is holding back some power.Ask Snopzinski here on the hq about them..He has dyno results for single carb set up and dual carb set up.Also the t-6 toomeys are great pipes,but not for that motor.the t-5 or cpi,shearer,set up will get you a lil more pop.Does the cylinder have a spacer plate on the bottom of the cylinder?As far as the vibration goes it depends on how radical it is.Most banshees have a lil vibration just from being the twin cylinder design.If you do end up pulling the head off for some reason you will need a mic to measure the id of cylinder,also get a mic to measure how far the piston goes down into the cylinder.Hope this helps you out a lil....Do a search on some of the questions and alot of them will be answerd..JB

[25THZ28]

Checked the compresion, engine cold, 15 kicks each side I had 150 psi, so thats good. I still may rip it apart to have the crank trued just to be safe. I'm gonna pick up new plugs and jets and engine oil tomarrow on my way to work. I took the carb apart and found out why it was flooding. Had a chunk of rubber under the float valve. I researched the carbs and it looks like I may go to a twin set up, but I think I'll run the single for now just to see how it runs. I plan on ice racing it next winter so I'll need all the bottom and mid I can get. Not sure what I'll do about the pipes, I'll probably just leave them until I can do more research. Right now I think I'm going to concentrate on cleaning it up and getting it set up for my riding style. I also have to get the rear of the frame straight. It's a little tweaked, but not by much.

[fastrthnu]

if you have access to a small enough telescoping bore mic, you can prob measure it through the exaust port w/o pullin the head.

[25THZ28]

I printed out Trinity's instructions for their 420 kit and it didn't come with a spacer plate, just pistons and gaskets for the most part. I will just have to order a gasket set some time and just take it apart just to make sure. That way I can get an accurate measurement with the mic. I think I am probably going to look into getting a dual carb set up for it and Trinity stage IV pipes, I was never a big fan of mixing aftermarket parts. So if you know someone with a set of Trinity pipes, that might want to trade for my Toomey's let me know.

 

I also need to find out what domes I have in the head. With the compresion I have I am going to have to run some spendier fuel. What is the best mixing ratio for the fuel? I have seen in the book it says 20:1, but I have seen people recomend up to 40:1.

[DallasGDub]

I have know idea about the stroke on a 420 kit, but know 1 way you can measure the stroke to see if it is stock with the head on. Just measure TDC to BDC with the drop probe on a caliper thru the plug hole. If you can not Zero out your caliper at TDC, just make a note of what you start with, and minus the diff from what you end up with. 54mm is stock stroke.

 

If Trintiy heads are like other brands, they will etch the size of the dome on the side of the dome itself. I am sure someone will be able to tell you if they do it this way or not.

[bode1]

I had a Trinity head. It had a number stamped on one of the domes when you took them apart, don't remember exactly where though. I only took it apart once after I put it together the 1st time and one of the o-rings looked a little iffy would have replaced it if I was reinstalling it.

[BoostedRex]

I just picked up a used trinity motor with the stage 4 head and stage 3 jugs. My domes have 18cc and 420 etched into them so you will be able to know what they are :thumbsup: . But the thing that blows my mind is that the jugs are resleeved and bored out to 69mm.

[BumpaD_Z28]

Congrats on the BANSHEE purchase ...

 

BUT "I" noticed the screen name .. are you running a 1992 Z28 ???

 

If so PICS !

 

~DaVe

[25THZ28]

Congrats on the BANSHEE purchase ...

 

BUT "I" noticed the screen name .. are you running a 1992 Z28 ???

 

If so PICS !

 

~DaVe

 

 

I do have a 92 Z. I bought it when I was in South Dakota for college. It's been sitting for some 6 years now. I'm not in to big of a hurry to get it on the road. The roads up here aren't the greatest. I'll see if I can find a pic and post it with the writeup on it.

 

 

As for the shee, whee on te dome was the cc etched? I'm guessing I will have to remove the head to check.

Yeah, I was going to check the stroke with a dial caliper tdc to bdc, but from the instructions that trinity had there wasn't a new crank in the kit, unless he bought the aftermarket stroker crank.

 

Say, are the swing arms weak? I am pretty sure mine is tweaked a bit.

 

Also, are all the frames from 1991 on all interchangeable? were there any differences? I may pick up an extra ust in case.

[C&B]

I printed out Trinity's instructions for their 420 kit and it didn't come with a spacer plate, just pistons and gaskets for the most part. I will just have to order a gasket set some time and just take it apart just to make sure. That way I can get an accurate measurement with the mic. I think I am probably going to look into getting a dual carb set up for it and Trinity stage IV pipes, I was never a big fan of mixing aftermarket parts. So if you know someone with a set of Trinity pipes, that might want to trade for my Toomey's let me know.

 

I also need to find out what domes I have in the head. With the compresion I have I am going to have to run some spendier fuel. What is the best mixing ratio for the fuel? I have seen in the book it says 20:1, but I have seen people recomend up to 40:1.

1st off welcome to the HQ. I had the motor youre talkin about and FROM experiance the CPIs i have now were tons better than my Trinity pipes. I ran 34mm mikunies and the motor responded well to them. I had a 4mm crank in with this set up and it ran hard. If anything else comes to mind let us know..... Oh BTW youll be sellin that motor for a bigger one sooner than you think lol i also ran/run redline at 40 to 1, the dome size is stamped in the front of the dome. Mic youre base gasket so they get you set up right.

[25THZ28]

I am pretty sure I'll be happy with the engine the way it is as long as I get it tuned properly. The trails are a little to tight for anything bigger and we don't have any dunes to speak of up here. The closest thing we have is a place called Jim creak, and it's mostly just silt. The riding is ok, but the scenery is better, but lots of maintenance afterwards.