Bonneville America Forums Forums Technical Forums Performance Mods Running Rough after Putting on SS pipes

Hi all.

Before I go out and pull my carbs apart, I wanted some advice on my situation at present.

I put on the SS pipes that arrived yesterday (awesome sound) and without doing any adjustment (got dark) I decided a quick fang was in order.

Well she was running fine for about 5k's and then all of a sudden it was like she was running on 1 cylinder.

So I ran up a side street before stalling and being dark I wasn't able to do much. She would start after a while but mainly with the choke out but again, like she was on one cylinder or something. I then adjusted the leanest air/fuel screw out a turn and she ran a lot better but still not great.

Got her home and now this morning plan on pulling both carbs apart to change jets, needles and do adjustments etc.

Now my theory is she was too lean and probably mainly cos of the pilot jets but just for interest, I was hoping some of my learned mechanical gurus out there could give me their wisdom on what they thought happened.

I would also appreciate advise on whether I should keep the 150 jets in or change them for 155's, use stock with one shim or tbs needles and fyi, I will be changing to 145 pilots.

Thankyou to anyone who has an opinion on this one for me.

Staffo

ps: Holy Dooley, the SS pipe's are simply awesome compared to the tors. Like a growling tiger or something.

leave the mains, could try a shim, and turn the screws 3 turns to start and see how it feels then go from there

Frank

Don't monkey with the mains yet, put in the 45s wiggle the mix screws a bit and give us an update. The pipes are awesome, aren't they?

Excellent, thanks guys. Yeah, I'm thinking the 155's might be a tad rich I don't know, but for now I'll keep the 150'
s in like you suggest and just put a shim under the stock needles. I'm also hoping that with the 45 pilot jets, the difference in the air/fuel ratio adjustments screws aren't as different to each other as before (see signature)

Cheers guys, I'll keep you posted.

Out to the shed now

Oh, I forgot to ask. Is there anything I should know about changing the pilot jets cos I haven't done them before?

I've just put the shim on the stock needles and now I'm at the point of trying to unscrew the pilots. You're right regarding finding the right sized screw driver though. I've got one which is just a little bit too long so that when it's up the spount so to speak it's not perfectly straight. Anyway, I tryed with a little bit of force to unscrew but stopped just cos like you say, don't want to bugger it.

So now I'll do exactly what you said and engineer if I have to the best screw I can, then I know I'll be able to apply enough pressure to get it out.

Thanks for the tips fellas.

Back to it.

Ok, 45 pilots are now in but not without having to make the screw driver smaller and using plyers to assist turning.

Anyway, the pilots I took out on my 05 speedie were 40's. so hopefully the 45's will be on the money.

Back to it:

You're good to go...rumble on brother

Thankyou my friend.

To finish up then, I initially adjusted the air/fuel mix screws to be at 2 turns, and with the choke on, pushed the starter button.

Vroom. Straight off the cuff there she is putt putting away in her new rumbling voice. MMM, may need to give my Sheila a bit more respect out there on the tar.

I then gave her a couple of twists of the throttle and, VROOM VROOM, she barks back at me like she's saying, I'm a new women and don't you forget it .

Well the response is excellent with no hesitation at all and I'm thinking, this is nice and easy

Anyway, after a bit of tweaking it looks like about 1 turn out is about right for now, so I'll leave her there for the test ride in about an hour after lunch and syncing the carbs.

Thanks for your comments and opinions too, I really appreciated them. Sort of like you're working in a garage with a bunch of mechanics who are there ready to help as necessary. Fantastic

Just tried to drop you a note, your PMs are full.

Righto, I'll delete some of em

I would be interested in you final set up. I have the Freak and SS and will be changing my jets soon.

Hi Anthony,

what settings do you have at the moment, cos I believe I've got mine pretty close considering everything.

After my hour ride yesterday for instance, she just ran so well it was euphoric. In fact I can't remember a time lately where I felt as good or confident with my Sheila's performance. Really responsive and strong through the entire range. Of course I'm just not convinced yet there may not be a little bit more there to be tweaked, but maybe I'm just a greedy power freak, drunk on the exiloration .

Then of course there's the pipes sound. You've got to be kidding, how nice is that. For me it's been a classic case "you don't know what you don't know".

here's an idle clip but it doesn't do them justice


Anyway, The rest is just tweaking to squeeze out that little bit more, so I've spoken to the local dyno shop and should be booking in within the next few weeks or so.

What I love about these open type pipes and the K&N's though is the settings are pretty much a standard now.

For instance at the moment I have 150 mains jets but some think you can get away with 155's. Then there is the 45 pilot jets which from reading other's posts etc seem pretty well right I think. Regarding needles, there's debate whether tbs needles may do a better job than stock with one shim, but again only trial and error and preferably a dyno will determine which. The only other factor is how many turns of the air/fuel ratio which in my case appeared to be a bit over 1 turn but it's early days yet.

So I'll be going for another ride later because it's a beautiful sunny day out there, so I'll see what 1 1/2 turns feels like but whatever, she's running beautifully now and I'm pretty bl#ody happy.

Don't forget guys, your altitude has a lot to do with your set up so what is good for one person may not be for the next.

I am below 1000 ft sea level.

Right now my jets and a/f screw is stock. I just put the pipes on, but have not had anytime to play with the jets.

Right now, I have the 45's that I will install, I need to order the D-tool from Brent @ newspeedmaster.com and an assortment of other jets. Probably start at 150's, but order the 152's and 155's. I have some 160's but fear that it may be too rich.

While everyones situation is different. It seem that the consensus starting point is 45/150's.

yep I would say that's a good starting point. You can get the mixture screws out with needle nose pliers or hemostats then carefully cut a slot in the head , then you don't need a D tool. You can also make a D tool by flattening 1 side of a piece of break line.

Tony-

I have SS short slashes, open pods (Freak-like) and also am below 1000 ft. I run 150 mains with 45 pilots. I'm at about 2.5 turns out on the mix. Also drilled the vacuum ports, but I think your year are already wide enough. Runs like a bat outta *^%$ with almost no decel popping. I'm a happy guy.

yep, I agree with the 150/45 jets being a good starting point as well. I have been following what other's have as their setup for a long time now which is why I started their.

I also asked many people what they thought (as you are) and it's just couldn't be too far off given how she is performing.

I must say though, when I open her up she is just so smooth in acceleration, there is no difference between one part of the throttle to the next. This makes me think I must be very very close to optimum. In fact I've been thinking of maybe putting in the 155 jets I've got but I have the sneaking suspition they WILL be too rich. Mainly cos I am at 2000', meaning thinner or less air requiring less fuel.

So 152's may be alright, as may be tbs needles. In fact, for fun I was thinking I could put them in today just to see how she goes.

So that's me at the moment.