FUEL SYSTEM PROBLEM, CARB. SPUTTERS AT HIGHWAY CRUISING SPEED. NEW STAGE 1 INTAKE. V&H EXHAUST. REJET OR OTHER PROBLEM?

[mleach72]

Can you guys save me a test ride?
OLD CARB= 076 main (078 is stock for 117), auxiliary plug was still installed, excellerator pump was in bad shape plugs dark, stage 1 air filter, V&H exhaust.
NEW CARB= new excellerator pump, 078 main, pulling out auxiliary plug, new Moroso plug wires, would like to use stage 1 filter but for testing just putting teardrop back on. V&H exhaust.
Should I start with 031 intermediate or start out with next higher intermediate?

31 should be fine. Get it running, adjust the idle mixture screw and take it for a ride.

 

[QMChief]

Should work!
Too bad XXX Carburetors is gone (Bob Maltz died).
He made some killer Super G modified carbs.
Gave him my engine and exhaust specs and when I received the carb it was dialed in!
View attachment 125505

Dave come to think of it I was considering the ZIPPERS THUNDERMAX which looks like Bob's carb but not as nice looking. Are you running one of Bob's carbs? Is it still going strong?

 

[DynoDave]

Dave come to think of it I was considering the ZIPPERS THUNDERMAX which looks like Bob's carb but not as nice looking. Are you running one of Bob's carbs? Is it still going strong?

Sold my bike a couple years ago but it ran great!
Going from the stock Super G carb to one of Bob's carbs made a big difference.
It's a good thing the bike had a rev limiter because it would hit it really fast!
S&S Super G carbs have been around a long time. They work very well, are dependable, and are easy to tune and work on.
One of their drawbacks is that they are a two circuit carb; low speed circuit and high speed circuit. If you tune them to run well in the midrange (most do) you lose optimum power on the high end, and vice versa. Adding the thunderjet effectively added a third, high range circuit. In addition, Bob made several other performance enhancing modifications to the carb. He was a wizard with carbs! Many other Big Dog owners installed his carb with great success.

 

[QMChief]

Guys I'm stuck on the throttle return spring. Not a lot of info that I can find. I heard a slight pop when I took the cables off and after changing parts I'm trying to figure out if you just put the spring back in place or is there a bit of torque involved such as winding the spring slightly to put it in place. If I get that solved I should be riding in a day or so depending on the weather.

 

[DynoDave]

I don't think you wind the spring. It's a good idea to use a good lube on your throttle and clutch cables. This is the stuff I like; https://www.amazon.com/Bike-Aid-Dri...752c75c07ae337bdb92efc741f387888&gad_source=1

 

[HMAN]

Guys I'm stuck on the throttle return spring. Not a lot of info that I can find. I heard a slight pop when I took the cables off and after changing parts I'm trying to figure out if you just put the spring back in place or is there a bit of torque involved such as winding the spring slightly to put it in place. If I get that solved I should be riding in a day or so depending on the weather.

Just put the spring back in place and procede as usual.

 

[john sachs]

Should work!
Too bad XXX Carburetors is gone (Bob Maltz died).
He made some killer Super G modified carbs.
Gave him my engine and exhaust specs and when I received the carb it was dialed in!
View attachment 125505

Removed the booster, on 3 different "G" carbs. Re-installed the S&S main discharge tube, properly jetted, and picked up 3-5 H.P. on the dyno.
John

 

[QMChief]

I finally found a youtube vid on winding the spring. It's not found in any s&s video, probably because IT"S A ROYAL PAIN IN THE ASS. I'm a day or so away from the final "oh shit" moment when I start her up for the first time after all the work. I appreciate all the help up to now from you guys. My back has been an issue in not getting her fixed up as fast as you young assholes so no haters please. I may need help fine tuning so I take back the asshole part.

 

[QMChief]

Removed the booster, on 3 different "G" carbs. Re-installed the S&S main discharge tube, properly jetted, and picked up 3-5 H.P. on the dyno.
John

Where do those go? Never seen them but if I'm going to use them now's the time! What do they do, where are they installed, what do they replace?

 

[Rottweiler]

I finally found a youtube vid on winding the spring. It's not found in any s&s video, probably because IT"S A ROYAL PAIN IN THE ASS. I'm a day or so away from the final "oh shit" moment when I start her up for the first time after all the work. I appreciate all the help up to now from you guys. My back has been an issue in not getting her fixed up as fast as you young assholes so no haters please. I may need help fine tuning so I take back the asshole part.

Hey I resemble that remark. It took me a week and a half to put rear shocks on mine. It doesn't matter. It's the smile on your face when you get done and back on the road.

 

[HMAN]

Dont take back the 'asshole' part until ya meet some of us! There are a few of us that wear that label proudly! And you may be one of the 'young ones'. 64 aint old in these parts.

 

[Rottweiler]

Also a few of us that might be in the old label as well. Damn it.

 

[QMChief]

Got her started and I was pleasantly surprised. Of couurse getting her to idle properly and running good on the highway are two different animals. I am just praying for steady cruising at highway speed and tan plugs.
I'm 66 years old and feel like 76. I hope someone can relate to that, but riding my great running Dog in nice weather makes me feel young again!!!

 

[john sachs]

Where do those go? Never seen them but if I'm going to use them now's the time! What do they do, where are they installed, what do they replace?

They replace the main jet discharge tube. They take up space in the carb bore, . Supposed to atomize the fuel better.
John

 

[john sachs]

Where do those go? Never seen them but if I'm going to use them now's the time! What do they do, where are they installed, what do they replace?

You would be better off, installing a "Thunder Jet" in your carb.
John

 

[QMChief]

Here’s my plugs after first test run it looks lean what do you guys suggest idle mix screw out a little?

 

[QMChief]

Here’s my plugs after first test run it looks lean what do you guys suggest idle mix screw out a little?
View attachment 125708

I'm on 040 air bleed, 031 intermediate, 078 main jets right now, teardrop filter, V&H exhaust 117 motor

 

[john sachs]

How many miles are on that plug ? What cylinder, front or rear ?
John

 

[QMChief]

How many miles are on that plug ? What cylinder, front or rear ?
John

Only 10 miles or so on the new plugs, 3 of them with the rebuilt carb. That was the rear cylinder. I can't tell if they are showing lean or acceptable. I did hear a spit from the carb. Not sure if I need to re-jet or keep trying to tune.

 

[mleach72]

Here’s my plugs after first test run it looks lean what do you guys suggest idle mix screw out a little?
View attachment 125708

I would say that plug is probably in acceptable limits. Plugs give you a ballpark idea, but shouldn't be relied on for perfect tuning. Sooty is very rich. White is very lean. There are many shades in between. If the bike runs well, you probably got the right jets installed. If you are getting excessive carb sneezing or if you feel the bike surging under steady throttle, you probably need a bigger intermediate jet.