Bandit Alley
MODEL SPECIFIC => SUZUKI BANDIT 600 thru 1200 - AIR/OIL COOLED TECHNICAL => Topic started by: Bazza on April 30, 2005, 04:56:29 AM
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I have been toying with the idea of going to 17.5 pilots on my B-12 with Ivan's kit. I have not been entirely happy with the idle on my beast.
Just wondering if anyone has done this and were they happy with the results.
I get a fair bit of surging on cold days (many of them here) but it does idle ok on warm days.
I now have the bike set up to run like a dream just a little rough on the idle. It appears that after 3.5 turns out on the screws, meetering is not as percise so I thought perhaps the larger pilots might cure this.
Any thoughts?
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I would syncronize the carbs, assuming all your other tune up stuff is in good shape. Even if you did sync them, I would do it again before changing pilots. Are you running an ignition advancer? The bike idles smoother at stock advance. Are all you intake boot clamps snug and the vacuum plugs snug in place, no intake air leaks right? All vacuum tubes are good. Check them all, any fresh air getting in between the carbs and the block will cause irregular idle.
If, after you are sure that you have good carb balance, you are still not happy, call Ivan. He certainly knows his stuff and has a good reputation for helping his customers. He has taken calls from me, and he doesn't know me from Adam.
My guess is that if your bike runs like a dream except for idle, changing out the pilots will degrade performance.
Steve
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Hey Steve:
I did speak with Ivan on one occasion and I would agree he was very helpful. In our conversations, Ivan put blame on the climate I live in and he is very correct.
In a regular riding season, we can go from 40 degress 10% humidity to 75 degrees & 85% humidity. I can safely say bless the genius who can make a jet kit with these climate conditions and to be fair, I do not think anyone can tune a bike on the phone. (Alititude here is 2200 ft above sea level)
I am down to the 2nd clip position on the needle valves (which Ivan stated is very rare during our conversation) but the bike has no hesitation or dead spots at all on the 2nd clip here.
I have tried just about every combination imaginable with screw positioning and needle valve settings. Someone mentioned in a very early post on the old site that the 2nd gen B-12 A/F mixture screws function becomes less accurate after 2-3.5 turns and this seems to be the case on what I am experiancing.
I will emphasize that the bike runs very strong with Ivan's kit, I am just trying to perfect it at this point. This is why I threw out the question if anyone had gone with a 17.5 Pilot.
I would buy another kit from Ivan in a second.
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Not sure about the gen II models but we Gen 1'ers used to raise our idle to the point where she's smoother on the transition in Georgia corners when rolling on the throttle and to keep the oil circulating better to keep the cam lobes well lubed.
When I got my Bandit, it was idling at about 750 and smooth as silk. Bringing it up to about 1100 where I like it and where recommended has it trying to run on both the idle and pilot circuits so it's a little uneven. This is normal. If I turn it down, it goes even again. Behaves like this with 32.5, 35, 37.5 or 40 pilots. It's just characteristic of the carb design.
I just wanted to mention this. You could be wasting your time. If the idle's high, turn it down to "stock". If she's even and pulls clean from a stop, the pilots are fine. YMMV
Good luck!
Marc/Atlanta
'99 Green B12
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Hey Marc:
Thanks for the comments.
The problem I am having is lumpy idle which gets better with the screws out to 4 turns. Anymore than that it appears that the screws loose their fine tuning capabilities (Best way I can describe it is that after 4 turns, its like opening up the garden hose all the way).I have not been the only one to experiance this.
I know Dale recomends larger pilots in the 2nd gen up to 3000 feet above sea level. (Humidity is also a factor)
Oh and I should point out all the carbs have been synced etc. I usually run the idle at 1300 rpm.
I will be trying the 17.5 pilots this weekend so I wil find out soon enougn.
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I would definitely go with the 17.5 pilots.
I'm thinking about doing the same thing myself. 4 turns out with the A/F screws seems too much... like it's overcompensating for insufficient pilot size.
Let me know how it works if you do it.
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I'm over 3.5 turns out too and it sounds like a lumpy cam.
Please post as soon as you test this.
My carbs are coming off soon and I was thinking I might have to do this along with the stage 1 kit.
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I have Ivans kit in my 01 B12. I'm out to 4.5 turns on the fuel screws and that seems to work good. I've got my needle clip right in the middle. I'm at 3,700 feet.
I should also say that I have 110 mains. With 112.5's as it comes with I was getting some heasitation at certan throttle openings.
With the 112's, four turns on fuel screws worked good.
Let us know what you find out. Will be interesting to see if 17.5's help.
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Hey Bazza, I slipped in some 17.5 pilots. Haven't tryed them yet because it's raining.Seems to work better at an idle so far.
Have you tryed them yet?
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Bump.
Whats happening Bazza?
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Well the 17.5 pilots have my 12 pulling the front wheel again!!! It hasn't done that for quite some time now. There are some issues however. It has developed a nasty hesation if you grab a handful (like wide open) of throttle at anything below 6,000 rpm. I'm going to mess with the fuel screws and/or the vent tubes to try and fix this.
So far however I really like it !!!!
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Got her spotted now !!! Tryed pulling the Vent tubes but that didn't help so I upped the fuel screws to 4.0 turns. That did the trick !! Runs really good and I'm a happy biker again !!
If you are thinking of 17.5 pilots keep in mind that I'm running 110 mains. I think with the 112.5 mains somewhere around 3.5 turns for 17.5 pilots should be ideal.
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I have still not got the 17.5's in yet as I have been way too busy at work. I promise I will get them in in shortly!
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Well I tried the 17.5's today and the beast ran very rich. So rich in fact I could light unburned fuel in my pipe with a match. I am back to the 15 pilots needless to say.
I am now at 3.5 turns out with the clip on the 2nd position with a shim. I am hanging a bit when I blip the throttle so will crank the screws out a 1/4 turn tomorrow.
I am getting close to a perfect idle now though.
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Thanx Bazza.
I'm going back in.
Wish me luck. ;)
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Well I tried the 17.5's today and the beast ran very rich. So rich in fact I could light unburned fuel in my pipe with a match.
Not to doubt your thoroughness... but are you sure everything was put back right? Going up to 17.5's from 15's shouldn't come close to causing that kind of problem. Some people even recommend using 27.5 pilots, in fact.
Did you turn your A/F screws back in a little after you put in the 17.5's?
Before you rip out the 17.5's... I'd double check your work.
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You described the garden hose effect do you mean it gushed fuel? if so did it escape from your large fuel hose connected to the carb plastic nipple?
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Hey Guys:
When I installed the 17.5 pilots, I turned the screws back from 4 out to 3.5. When I started the thing, it began to belch white smoke (and I mean lots). I took the carbs back off, and inspected, everything was normal. Re-installed the carbs and set the scres to 3 turns. Less white smoke but still smoking. The pipe was wet with unburned gas. (I could light it with a match)
Took the carbs out, put the stock pilots back in, and it ran fine after I moved back to 4 turns out. I can't believe what happened, and have no explaination for it. I would agree with PaulVS here, I would have never believed this would have occured. I thought I might run a little rich but nothing like what happened. (I did add 17.5 pilots to a friends Bandit with Dales stage 1 kit and the difference seemed marginal on his bike)
I am curious to hear what any others experiance.
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just thinking out loud---i read somewhere that if you change pilots,some have 6 holes in them and others 8,and the reference said under no circumstances use the pilots with 6 holes,may be worth a look as ive run 27.5's and the only obvious diff is the 1/4 mile time. slo.
slo coach
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Keep us posted Steve!
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Ok kids, I did get the 17.5's to work. (I think I may have had a stck float bowl on my last attempt.)
I am now at
3rd clip
Airbox Mod
112 mains
17.5 pilots
Screws at 3.25 turns out.
Did it make a big difference? From what I can tell, I am getting a slightly better idle but now there is a real fine line between running rich (RPM's dropping with a slight throttle blip at idle) and running lean (RPM's hanging while blipping the throttle slightly at idle.
I am now at 1/8 turn adjustments, but it is almost perfect at 3.25 turns out. (I was at 3 3/4 turns out with the stock pilots)
I maybe see a slight increase in power when I spool it up from idle but I would emphasize it's very slight, and probably could have got the same affect with the stock pilots had I tried fine tuning them as much.
The general consensus here is that it's not worth the effort if your getting a good idle.
Bazza