Yet another single carb thread :) Dan's 1" runners from plenum to custom head flanges

[slabghost]

Sounds like great news to me.

 

[Steve83]

I'm smelling success!

 

[ekvh]

You named this thread right. Good job, Dan. Now who's gonna put one of these on each side??? Come on, you know you're thinking about it. Dual 2bbl down drafts!!

 

[backlander]

Nice job Dan, that's a very clean, neat set up. Initial ride report sounds very promising.

 

[joedrum]

I don't know eric ..I like having it all tucked away ...where it suppose to be

 

[dan filipi]

Talking with Joe, we don't like this whole power valve deal in the highest possible mpg equation so we're looking to eliminate it and control fuel with jets alone like it used to be before EPA crap and lean burn idle.

I went and pulled the power valve diaphragm spring out and went for a short test ride.
Can feel the power valve definitely richens up the mixture because take off power was reduced quite a bit.

So....I swapped the primary and secondary air bleeds.
That made it 160 secondary, 175 primary.

On this ride take off power was better but still low.
Can feel it's too lean because there's a slight surge when the accelerator pump dumps gas in then the power drops back.
WOT is awesome and probably where I'm going to leave it.

Joe and I are looking to increase the primary jet size from 107 to 110 or 115.

Anyone know an inexpensive source for jet or micro bits?

 

[backlander]

I'm building a set of modified OEM carbs and found some micros locally at an Ace Hardware store for 1.84 each, they had from about #30 up to the #60 but ended up finding some on amazon.com for anywhere from 9.00 to 30. dollars for drill sets #61 through #80. I haven't ordered these yet. I bought a set of 4 different size collets (Dremel Brand) at Walmart for 10.00 to hold them. This is the cheapest place I've been able to locate weber jets but I've never ordered from them. https://www.carburetion.com/Weber/weberJets.asp Seems they all run 5 to 8 dollars each at the different places I've looked at.

 

[slabghost]

Here ya go.
https://www.ebay.com/itm/New-21pc-Micro- ... 3f1a93b0f4

 

[dan filipi]

I'll probably have to get these weber bits. https://www.ebay.com/itm/280932387076?it ... m=&vxp=mtr
So many of the others don't have the right size.
I need a #56, 1.15 mm and a 1.20.
I could just buy the jets but since I'm after highest mpg and performance I'll be doing changes, not just to the primary jets but maybe the air jets also.

 

[dan filipi]

Start this morning at 52 degrees in the garage,
3-4 twists to shoot gas in, then a few twists while running to keep it running.
Held rpm at 2500 and set the throttle lock.
After a couple minutes it would idle at 600 rpm.
A minute or so later it came up to 950.
Engine temp was at beginning of thin white line.
Acceleration sluggish but no spits or pops.

It's becoming evident to me that although this carb does well out of the box, there's a lot more can be done to tweak it.

 

[westgl]

Wow! I am not on here for a few days, & come back you guy are kicking a$$ and taking names.

That is GREAT!!!!

Dan

As you are leaning the jetting, I am wondering if you may have a need to start using the choke during your idle up & hold startup, to pull more fuel in, which is fine, just a thought.

You are going to go richer on the primary main jet for better take off, sounds good.

When you swapped the primary and secondary jet stack did you also swap the main well tubes?

I was just trying to get a sense of what jets are where

 

[dan filipi]

Cold start right now is pretty good.
Granted it would be super nice to have an automatic choke and I'd settle for a manual cable, but I don't think with my year round riding weather I'll need it.

Right now as it sits the only change I have in place to jetting is going from a 210 secondary air bleed to a 160.

I went back to what the jetting was otherwise so I can get in my mpg test tomorrow. This way I'll get a accurate comparison with the new runners.
After that I'll be experimenting.

 

[westgl]

wow!

You went 210 down to 160.

I have 220 in mine, so there is some more power & MPG's to be had by leaning the jets some,

I have not gone that far, yet.

Good to see it is running much better.

I look forward to some good MPG ##

 

[dan filipi]

westgl » Fri Nov 01, 2013 7:13 pm[/url]":z7rpo6r5]
wow!

You went 210 down to 160.

I have 220 in mine, so there is some more power & MPG's to be had by leaning the jets some,

I have not gone that far, yet.

Good to see it is running much better.

I look forward to some good MPG ##

Actually the air bleeds work in reverse.
A smaller hole in the top will enrichen the mixture.

I'm not sure what effect this has on the secondary main jet, possibly it could go leaner but I'm happy with secondary and real world riding I won't be in the secondary barrel very often except for fun and passing.

There are so many possible combinations with these carbs and lots of experimenting and test rides to be done.

So far I'm happy with the 1" runners.
Other than cosmetics, they are done.

As far as the carb goes, the first thing I want to do is get rid of the power enrichener.
I might have the jet bits tomorrow :music:

 

[dan filipi]

Latest on the carb, I've got some problems with it,,

I've sealed the power valve/enrichen passages in a way I can go back if needed.
Gas was dripping past this valve when it should be closed, I could here it as the idle speed would change in time with the drips, and also with a slower return to idle with less engine breaking coming to a stop.

I found both primary and secondary throttle plates were not squared up in the bore. Doubt it's suppose to be like this so I loosened the 2 screws an got them squared up nice.

The venturis are removable.
Both of these are ever so slightly loose when seated. I'm pretty sure this has at least partly to do with my lean power condition.
I can't see any way that I can safely tighten them up to maybe seal better, if they even are suppose to be tighter and for a better seal. I don't know.

The logical next step is to jet the carb to what the engine needs.

 

[Dusterdude]

Dan,as i was re-reading this again,a couple of thoughts.i believe your power valve drip issue was caused by the valve not having the correct vacuum rating on it.power valves are rated by inches of vacuum and it would appear yours wasnt rated for the vacuum the engine is pulling.i wonder if different power valves are available for these carbs?and number two,where did you get the orange hoses for the runners?thanks

 

[dan filipi]

Could be on the power valve.
Mine was dripping gas at rest with the cover off.
Truthfully I don't know if that's normal or not.

The orange coupling came with the vw plenum I bought on ebay. There's a vw site that sells them but I lost the link.

 

[Dusterdude]

I would say that isnt normal,sounds like a bad valve.after some searching i found some boots.thanks

 

[Gashog]

backyardtrouble » Wed Oct 09, 2013 8:37 am[/url]":3afqo5dt]
I want to thank everybody for all the good info and being so nice here with your suggestions...I always try to rebuild my bikes back to orginal condition as much as possible, i guess that has to do with my nature about these goldwings, and now there are so many harley's here for sale now.. :smilie_happy: Most of them ask me..what year is that..so i'll them an 81 or 82 or so on.
Then it's like..are you kidding me...so i'll tell them...bring your harley back in 30 years and show me what it looks like, they'll all laugh and tell me..it will be in the scrap yard.. :smilie_happy: but sometimes someone wants something different like this single carb set up. I can unserstand that process too, so i am very thankful for all the info..I built my first honda when i was 11, but I know If it wasn't for Dan having this site when i bought my first Goldwing, i'm sure i wouldn't be doing these restorations now. I've spent the last 3 years building Goldwings, and serving customers in north west arkansas and surrounding states. I don't know everything, but i sure have learned alot. so i want to say.. :thank_you: Dan for the best Goldwing Forum.. :salute:

Not all 30 year old Harleys are in the scrap yard. 1978 Shovelhead (AMF too).