34pj idle difficulties

[Bansheenate]

I used to have a trinity 420 big bore with drag pipes using 34pj carbs. 172 main. 58 pilot and cel needle middle clip. Ran and idled perfect. They stopped re-sleeving that motor.trinity told me it was outdated. So I built a small bore motor with triple exhaust ports and used same pipes with 17cc domes. Dynatech ignition. Race fuel and so on.i have had other banshees run same carbs without triple exhaust ports idle fine with a 58 pilot. I could not get my new motor to idle. I finally went down to 42 pilots with the cel needle one notch down from top. 1-1-2 turns out on the air screw and 160 mains.choke/idle adjust like 9turns out. For anyone out there trying to get their 34pjs to idle "don't give up". It took a lot of time and effort.just wanted to put that out there because I searched for help and saw a lot of people trying to help someone else,and they never told the outcome when finished. which doesn't help anyone. Thanks.

[trickedcarbine]

How are you trying to help people when your entire post is missing the actual info to set the idle on PJ's? They are simple yet finicky. Just turn the choke knob in all the way. Put a mark on it with a paint pen. Back it out 6 1/2 - 7 1/2 turns.

[Bansheenate]

It wasn't the choke/idle knobs alone that got it to idle. I did state how many turns out I put them. My post was about how perfect your slow jet needs to be,in order to get them to idle.when I had the 58 pilots in,it wouldn't idle no matter how far out you turned in or out the idle/choke knobs.on a pwk you can simply turn the idle screw in to raise the slide,and make it idle,even if you are running a little fat on your pilot jet. With pj carbs its not that easy.you make it sound like you simply adjust the choke knobs and it should idle fine. I have worked on many drag ported banshees with 58 pilots that idled no problem on pj carbs. This was my first experience with triple exhaust ports on a 350. I've heard other people post that the Cubs,which have triple exhaust ports also,don't like a lot of fuel down low.even Duncan racing suggested starting out with a 58 pilot.sorry if my post wasn't perfect enough for you to understand.it was mainly for people struggling with the same problem I had.

[jbooker82]

Or just get PWKs and be done with it.

[trickedcarbine]

Fire the motor and use throttle to idle the bike while you establish if it's rich or lean on the pilot. Make the proper jet change. Now set idle.... That simple. The main and needle changes you mentioned have nothing to getting the PJ's to idle.

 

Not trying to bash you, but you are making a simple process sound way to complicated and your jets posted won't work for everyone. Also, if you are 9 turns out on the choke to idle that is usually an indicator that the pilot is a bit rich as your air screw settings are pretty much spot on. The PJ's can certainly be a pain in the ass, but with the right understanding of how they work and good tuning knowledge they can definitely be made to run decent.

[Chukkinsod]

This is good stuff...Ive struggled with this for a little while now. Only diff is on Alchy and only drag. Have to stay on the throttle at initial clean out as well as on Shutdown "blip it' or it will stall....Im ALL ears on this discussion!

[trickedcarbine]

This is good stuff...Ive struggled with this for a little while now. Only diff is on Alchy and only drag. Have to stay on the throttle at initial clean out as well as on Shutdown "blip it' or it will stall....Im ALL ears on this discussion!

Weren't you from Michigan? One of Doc Fang's sled guys?

[Chukkinsod]

From Mi ...not a sled guy though. Outside Lapeer...Race at WMSD and PHMC and Phils for the first time last year.

[Bansheenate]

I am new to banshee hq.we are on this site because we are all into the same type of quad.you say your not trying to bash me,but you have a very negative way of expressing your points and views. I am well aware about the main jet not affecting the idle process.the needle,if lowered enough,will tell you if you are rich or lean on the pilot. The circuits overlap each other.just because you seem to think you have it all figured out,doesn't mean that other people don't want to know about what people have tried. Anyone who knows about jetting,knows that there are many factors involved. People just want a baseline to start with. Not everyone has a million dollars to spend on purchasing a bunch of jets,or a new pair of pwk carbs. In fact,the pj carbs might be outdated,but they force you to dial in your slow jet perfectly,if you want your bike to idle.I agree that I'm probably still a little rich on the pilot. Until I put a load on the motor with paddles I still won't be 100% sure. I was stoked that after starting at 58 and dropping one jet size at a time,all the way down to a 42,I was relieved that I was getting close. As you know,opening your dual carbs and changing jets can be tiresome. That's why most riders stay clear of jetting.I stated my main jet size just to put it out there. Maybe someone with Vito's stock bore jugs with triple exhaust ports might be looking for a baseline main jet size.I built my motor myself. Welded up the water jackets and ported my own triple exhaust ports.and no I did not weld up the entire water jacket area.thats probably what you would pick apart about my post. Anyways,this website should about helping people figure out problems,without having to go through the trials that guys like you and I have gone through the hard way.i am 39yrs old and wish that back in my younger days we had websites like this one to help you out with a problem you were struggling with. Remember that what seems easy for you,isn't easy for everyone.

[sleeper06]

Chuck, you might need to drill out the carb body in the pilot circuit, I've done it plenty of times on Alky bikes. The tiny lil hole that faces the intake doesn't flow enouph fuel at idle

[trickedcarbine]

I am new to banshee hq.we are on this site because we are all into the same type of quad.you say your not trying to bash me,but you have a very negative way of expressing your points and views.

(Yes, my apologies. Just trying to prevent misinformation.)

 

I am well aware about the main jet not affecting the idle process.the needle,if lowered enough,will tell you if you are rich or lean on the pilot.

(Not quite)

The circuits overlap each other

(No, they don't. Just the main and needle over lap. Put the carb in your hand and really examine what is happening in there. The pilot is on the motor side of the slide. When the throttle is closed the motor tries to suck through the bore but can't so the pilot feeds it like its sucking through a straw. Follow where that choke circuit goes though and see where it feeds from, there is a correlation there between the way the pilot and the choke circuit work in sync to a degree)

 

just because you seem to think you have it all figured out,doesn't mean that other people don't want to know about what people have tried. Anyone who knows about jetting,knows that there are many factors involved. People just want a baseline to start with. Not everyone has a million dollars to spend on purchasing a bunch of jets,or a new pair of pwk carbs. In fact,the pj carbs might be outdated,but they force you to dial in your slow jet perfectly,if you want your bike to idle.

(Right, but not every one can use your experience as a baseline. And in my opinion, it's far easier then you made it. Why make things hard on your self?)

 

I agree that I'm probably still a little rich on the pilot. Until I put a load on the motor with paddles I still won't be 100% sure. I was stoked that after starting at 58 and dropping one jet size at a time,all the way down to a 42,I was relieved that I was getting close. As you know,opening your dual carbs and changing jets can be tiresome. That's why most riders stay clear of jetting.I stated my main jet size just to put it out there. Maybe someone with Vito's stock bore jugs with triple exhaust ports might be looking for a baseline main jet size.I built my motor myself. Welded up the water jackets and ported my own triple exhaust ports.

(That's pretty friggin' cool! Skills like that and another couple years of tuning and you could be a force to be reckoned with)

and no I did not weld up the entire water jacket area.thats probably what you would pick apart about my post. (Nope, and it wouldn't matter if someone did and it was a strict drag bike)

 

Anyways,this website should about helping people figure out problems,without having to go through the trials that guys like you and I have gone through the hard way.i am 39yrs old and wish that back in my younger days we had websites like this one to help you out with a problem you were struggling with. Remember that what seems easy for you,isn't easy for everyone.

(If you can't take constructive criticism without needing to be defensive at 39, I doubt you would of took any advise back then.)

I only picked it apart because of your comment about picking it apart. You know you need to be right so I coddled you a bit.

[trickedcarbine]

Chuck, you might need to drill out the carb body in the pilot circuit, I've done it plenty of times on Alky bikes. The tiny lil hole that faces the intake doesn't flow enouph fuel at idle

Especially once you're over 400cc's

[Bansheenate]

Tricked carbine. Explain this. since you know so much at not even 30yrs old.after I figured out my main jet size by being out in the sand with paddles and putting a load on my motor. Next I wanted to work on my pilot circuit. Unfortunately,I had no pilot jets with me at the time I was somewhere where I could put a load on the motor. So the bike wouldn't idle and had a bog at lower end whenever I tried to launch.so I dropped the needle one notch at a time to see what it would do. Once the clip was all the way at the top in its leanest position the bike idled but had trouble idling down after a quick pass. This is when I knew I needed to lower the pilot to get it to idle without running lean at mid throttle.so lowering the needle will affect idle which I proved while jetting the bike.now that I have the 42 pilot instead of a 58. I am able to put back the needle to the 2nd down from top.next I'm gonna put in a 40 pilot and I bet I will have the clip in the middle and I will have my low mid and top dialed.so explain to me again how the needle has no effect on idle on a pj carb?and no I don't need to be coddled by you.everything I have learned is by trial and errors. Yes I have blown a few motors learning over the years and I definitely have lots more to learn. But I can say that I have never had to have my bike built by someone else. Every race I have ever won in the dessert was from my own doing.and yes I would listen to someone as long as they don't have a cocky attitude. Young guys tend to speak before they think. I know I used to be just like you.

[IsuckDIX]

 So the bike wouldn't idle and had a bog at lower end whenever I tried to launch.so I dropped the needle one notch at a time to see what it would do. Once the clip was all the way at the top in its leanest position the bike idled but had trouble idling down after a quick pass. This is when I knew I needed to lower the pilot to get it to idle without running lean at mid throttle.so lowering the needle will affect idle which I proved while jetting the bike.now that I have the 42 pilot instead of a 58. I am able to put back the needle to the 2nd down from top.next I'm gonna put in a 40 pilot and I bet I will have the clip in the middle and I will have my low mid and top dialed.so explain to me again how the needle has no effect on idle on a pj carb?and no I don't need to be coddled by you.everything I have learned is by trial and errors. Yes I have blown a few motors learning over the years and I definitely have lots more to learn. But I can say that I have never had to have my bike built by someone else. Every race I have ever won in the dessert was from my own doing.and yes I would listen to someone as long as they don't have a cocky attitude. Young guys tend to speak before they think. I know I used to be just like you.

You haven't proved shit. I am not sure about you, but I have never launched a bike from idle aka zero throttle. 

At idle, the main jet, and needle have zero effect. This is air screw and pilot jet that effect idle. Once you open the slides, then main jet and needle come into effect.

[trickedcarbine]

Tricked carbine. Explain this. since you know so much at not even 30yrs old.after I figured out my main jet size by being out in the sand with paddles and putting a load on my motor. Next I wanted to work on my pilot circuit. Unfortunately,I had no pilot jets with me at the time I was somewhere where I could put a load on the motor. So the bike wouldn't idle and had a bog at lower end whenever I tried to launch.so I dropped the needle one notch at a time to see what it would do. Once the clip was all the way at the top in its leanest position the bike idled but had trouble idling down after a quick pass. This is when I knew I needed to lower the pilot to get it to idle without running lean at mid throttle.so lowering the needle will affect idle which I proved while jetting the bike.now that I have the 42 pilot instead of a 58. I am able to put back the needle to the 2nd down from top.next I'm gonna put in a 40 pilot and I bet I will have the clip in the middle and I will have my low mid and top dialed.so explain to me again how the needle has no effect on idle on a pj carb?and no I don't need to be coddled by you.everything I have learned is by trial and errors. Yes I have blown a few motors learning over the years and I definitely have lots more to learn. But I can say that I have never had to have my bike built by someone else. Every race I have ever won in the dessert was from my own doing.and yes I would listen to someone as long as they don't have a cocky attitude. Young guys tend to speak before they think. I know I used to be just like you.

You are so all over the map with your approach. I was polite and even said I wasn't bashing you. You are the only one getting huffy because you were told what you are doing was wrong and now you wanna do this "I'm older then the young punk, so I must know more" thing. Get over your self. Your post was that of someone new to tuning, and had no real relevance to tuning a PJ carb properly. You then back it up with a story about how you build your own stuff in effort to turn your words to gospel. Fact is, I knew at 16 what you are just now starting to figure out, and I was putting info you needed, but for some reason you needed to act offended and get all defensive. At this point, I have nothing further to add as you are clearly 39 going on 13. I'm sorry I offered insight and will no longer continue any input. Remember guess and check can melt motors before you check. You may commence to doing it the hard way again.