Bonneville America Forums Forums Technical Forums Performance Mods Tuner issues!!

Here is my set-up. Stock pipes all baffles gutted. K&N Filter and all snorkels gone. The bike is running....kinda hard to explain. If I pull it to say 2500-3500 RPM it runs up fine. IF I hold that RPM it starts to stutter almost like you flicked the kill switch off and on really fast?? It also idles a lot rougher than it used to .

Here is the progression, changed out stock air cleaner for K&N no problems. Pulled the snorkels= problem started. I have never been into the carbs but am willing if anyone has any idea what I need to look for. Jets, needles, air mixture tweak? Just looking for some direction. I am new to the ride and really not wanting to take it to the dealer. However, if that is my best or most direct route I will. Thanks in advance for any help.

Check your vacuum caps and hoses to the airbox. Sounds like something is knocked off? Those simple mods would in no way have made the engine suddenly falter.

I forget, but believe this is a new bike, right? If used, check the in-line fuel filter, they clog easily. If you had the gas tank off, check the vent tube, they kink easily.

Ok, before this gets ugly

Start here and here.

I'm no tuner, but if you increase airflow in and out, you will have to increase fuel.

Thanks Al. It is used, I bought it mid December. I will check the stuff you referenced, thanks.

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Ok, before this gets ugly

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Don't want that!! I am at work and have to keep my eyes peeled for the network nazi...thats why I didnt do an indepth search. Thanks for the links I am headed there now.

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I have never been into the carbs

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You are running way lean if you have never rejetted. Rejet to about 128-130 and I bet you see a marked improvement.

Yup sounds like the lean surge thing. You need to re-jet. Hit pat's site and fire up the jetting calculator.

Yep,got the same setup,mine went way lean with the snorkle out.Rejet or put the snorkle back in.

Thanks all. Based on Pat's handy dandy jet thingy I need some 128's. I called my dealer, doesn't have any jets in stock...orders them on request. I guess the snorks go back in till I can get it re-jetted...GRRRRRRR!!!

most jap bike dealers carry the jets.
you should be able to find them in stock somewhere.

Thanks Pete. Put the snorks back in and did a little test run....aint that just the $^%*&'s. It is running fine again. I will see if I can find some .128's tomorrow.

Thanks all.

If you can't find 128s don't give up, some 130s would probably be fine. Either way you will want to tweak the idle air screws.

And balance the carbs

130's will work just fine.....Angelis

I remember when I first pulled my snorkle it ran worse til I got rpms up at WOT. When I re-jetted, 130's were too rich, ended up with 125's.

Nah, the pipes were already gutted. Weird isn't it.

when I first gutted my pipes , with air box , uni filter and no snorks, I was running 142 jets.
Now with very free flowing pipes and as open an intake you
can have without porting the heads I am running 170's

I still think you're nuts.

yup

Awe c'mon now Kenny, you saw my exposed valves!! Wouldn't even let me adjust your idle?

ya know I saw that jetting calculator and decided to play with it and I tell ya what. It seems to work. I was sceptical but it hit my jetting right on what I had already done and dynoed and my mixture is optimal and it is what the calculator said too. So on that note I can reccomend that if for no other reason a place to start!!

I don't let anyone touch my motor. Except what I have to have machined since all I have is a lathe and milling machine well and drill press and welders and such.

More accurately I don't have some of the tooling.

You're way ahead of me on the machines.... I have a not so true drill press, and a sheet metal brake and bead roller. That's about it. Oh and a bench vice and large hammer

How far north and easy in PA are you? Hoping to hit the Hawk's nest this year...

Update: I got in late tonight and started tearing her down. I had Pat's blow by blow on the puter and was trottin back and forth. Pat's instructions are priceless, everything just fell in step. Oh yeah, Pat, big thanks for the tip on rotating your carbs....just before I put them back in the pit I checked the throttle, sure enough it was bound up. I rotated the carbs to the right one time and everything works fine. I woulda been some kinda P&$^%# if I had buttoned the thing back up to find the throttle sticking.

O.K. here is the weird stuff. 02 BA all baffles out of stock exhaust, all baffles out of the air box. Whoever had the bike before me was running 142.5 mains and 42 pilots with all the baffles and stock air cleaner in the air box? The air screws were twisted out almost to the end of their adjustment. I put a set of 132's( big thanks Tom ) in drilled the slides to 7/64 and installed 1 shim under the needle, adjusted the mixture to 3.5 turns out. I have not run the bike yet, I had to install new airbox rubbers ( thanks Grump ) and new intake boots(picking them up from the dealer in the morning). Just for giggles I pulled the plugs, they were WET with black sooty gunk on them. The other thing I noticed, when drilling the slides, the intake side of the slides had the same black damp soot on them??? I will post the results tomorrow after I get the final assembly done. Thanks to everyone who provided advice/suggestions and especially the "free parts dudes" ya'll know who you are.

Man were you ever running rich! Darn near sabotage. I'm betting you'll see a vast improvement. Good job!

Sounds like you are on the right track. We were all fooled. We all guessed you were lean. I hope you replaced those fouled up plugs. Only clean, new plugs will give you a good reading on your new setup. Pull the plugs after a few hard miles. They should be a nice light tan or light gray.

I hope you have a big when you get back from your test ride.

Cody

Thanks Tom. Cody, again, good advice. I will pick up a set of plugs this morning before I fire it. Thanks.

New plugs are on the list of things that are just so cheap and such good insurance, there is no good reason not to! Good on ya.

By the way, bar ends going in today

I am just above Mt Pocono south of Scranton very close to where rt 80 and 380 meet. Ezcue has machines too from what he said I was telling him about the oil pressure gauge I made.

Yup Ezcue made me some goodies
At any rate, we should get a ride in this year.

Sorry for the lag on my results...been way busy at work. The thing runs like a scalded azz ape when you get in the fuel......dang near pulled me off the bike the first time I nailed it in third!!! It is still doing the stutter with the throttle barely cracked, no matter RPMS or gear. If I try to slowly roll through the stutter it feels "mushy" and then comes to life in a big, head snappin way. Stock pipes, all baffles gone, airbox de snorked and drilled K&N drop in, 132/42 3.5 turns on mixture screws. I cant help but think I am dangerously close to having it dialed in but do not know where to go from here. Thanks in advance for any..more, advice. Really, thanks fellers, no tellin what my bill would be at the dealership without all the help, thanks!

put it on a dyno, that will tell you if its dialed in or not

Frank

Ezcue, I had the stutter when the throttle is barely cracked and 1 shim under the needles did the trick, fwiw.

mike

Mike, thanks. I have a shim under each needle. I installed Nology coils and wires today but have not had a chance to run it. I did pull the plugs, left side is black sooted but not wet....right side is light tan to white?? Both mixture screws are out 3.5 turns. I have a friend who has a balancer. I am headed that way in the A.M. before I go any further.

Ezcue,
Ok, this is what you need to do first.
Warm up the bike, then set the idle to about 1100 rpms.
Turn both pilot screws in to about 2 turns out each. Then start the bike with one of the plug wires pulled off. Adjust the pilot screw on side that is running out until you notice th motor getting goofy - you will hear it, then back off until the motor is fine again. repeat for other side.
Then sync the carbs - carb sync is LAST thing you do.

Pat, thanks....I have really been struggling with this thing. I sincerely appreciate the advice. Headed out to do that right now.