carb overflow mystery

[wompin]

Wow, Big T, do I really need to go up 11 sizes on my main jet? Stock jet for my vm26ss carbs is 95. Keep in mind I am going to baffle my pipes so exhaust flow will be reduced. For Now, I have ordered 5 sizes up.

I took Steve's advice and went with 3 sizes up for pods and another two sizes up for custom baffled exhaust. Prior to that I was going off a suggestion of 3 sizes for my setup. I dont want this beast to drink fuel like its going out of style, so Im leary of going crazy with main jet sizing.

Ill get a photo of my carbs up.

Ive set my fuel screws at approx 7/8, hows that? I suppose air screws will then be at approx 1 3/4. I do have my pilot jet up one size from stock too. throttle stop screw is set at 2 turns in from just touching. Anyone got issue with these settings?

[Big T]

Wow, Big T, do I really need to go up 11 sizes on my main jet? Stock jet for my vm26ss carbs is 95. Keep in mind I am going to baffle my pipes so exhaust flow will be reduced. For Now, I have ordered 5 sizes up.

I took Steve's advice and went with 3 sizes up for pods and another two sizes up for custom baffled exhaust. Prior to that I was going off a suggestion of 3 sizes for my setup. I dont want this beast to drink fuel like its going out of style, so Im leary of going crazy with main jet sizing.

Ill get a photo of my carbs up.

Ive set my fuel screws at approx 7/8, hows that? I suppose air screws will then be at approx 1 3/4. I do have my pilot jet up one size from stock too. throttle stop screw is set at 2 turns in from just touching. Anyone got issue with these settings?

That's the baseline you should go for -122.5, info taken from what others have had success with for pods and a 4-1. Most people end up in the 120-127 range

You'll find your fuel mileage to be aorund 30, rather than mid 40s like stock

[wompin]

Thats good info to know. The main reason I went for pods was to eliminate the hassle associated with pulling the airbox/carbs. Its a matter of convenience for me. If I end up needing to jet at 120+ and wrecking fuel economy, I may just put that airbox back in...

Ill not give up just yet tho. One thing I do know is that opinions and information on pods and jetting varies about like opinions on politics or religion. Ultimately, I like to verify advice first hand. Wish me luck and thanks for the heads up.

[Steve]

The main reason I went for pods was to eliminate the hassle associated with pulling the airbox/carbs.

I am always intrigued by reading this statement.

Just how many times were you anticipating removing the stock airbox?

If you clean your carbs properly and winterize the bike properly, you won't have to remove the airbox for many, MANY years.

Yet, you are willing to go through all the hassle of removing the carbs MULTIPLE times to get the jetting right for the pods and pipe.

.

[chuck hahn]

122s will have ya way to rich...you can go there if you want, but 102.5 to 107.5 will be more to the bikes liking AND youll have less cussing and swearing doing the fine tuning of the system. Remember, once it up and running, you tune from the "bottom up" on VMs. Meaning you screw IN or OUT the pilot jet screws to get the best idle and lower range RPM ( think about 1/8 open throttle here ) response. Then you do plug chops or use something like a Colortune and adjust the mixture screw ( on the side of the throats).

[wompin]

I am always intrigued by reading this statement.

Just how many times were you anticipating removing the stock airbox?

If you clean your carbs properly and winterize the bike properly, you won't have to remove the airbox for many, MANY years.

Yet, you are willing to go through all the hassle of removing the carbs MULTIPLE times to get the jetting right for the pods and pipe.

.

I guess we all have our own brand of crazy, steve. Anyway Im mostly enjoying the learning process of this build. Hell, 5 months ago I had wouldnt have known a GS from my ASS.

[mrbill5491]

Last time I had my air box off before this rebuild was probably 12 years ago.

[wompin]

UPDATE:

I installed my dipped and rebuilt petcock, inline fuel filter, and carbs. I was unable to get my bike to fire up after much tweaking of pilot fuel/air screws and throttle stop screws, and choke. I even tried heating the garage (only got it up to 45 deg. or so). Note that I did install glass packed, perforated baffles in the pipes.

So, I was a bit at a loss. I decided to redip my carbs just for good measure. Before I put them back on I may try to wedge in that air box just to eliminate possible suspects. If the airbox supporters are right, this should be a cure all (or most) for the gremlins Ive been dealing with. If this works, Ill ditch the pods and rejet closer to stock. If it doesnt work, I think most likely my head will just explode right there on the spot.

[barnbiketom]

keep us posted!!

Although pods or airbox makes no difference in the initial post.. gas flowing out of the wrong place!!

gotta be carb problem not pod/airbox UNLESS cheepo pods are covering up the air bleed holes in the back of the carb then that's another can 'o worms haha

[cowboyup3371]

Honestly, unless your tank is extremely rusted inside, you don't need the inline filter and maybe restricting so much fuel as they just don't work the same with our petcocks/carbs like they do on cars. Try getting rid of that too when you put the airbox on for testing purposes.

[wompin]

Cowboy, I agree that normally an inline filter would be mostly unnecessary. I think it's more necessary now though, since my petcock has lost its filter screen. I did plug the ends of the petcock inlet tubes with stainless faucet aerator screens, but my theory is, last time I had the carbs on little sediment bits were keeping my needle jets open - hence the random overflow. The filter I got has a glass housing, and I can see fuel flowing through.

[Steve]

Good luck with the in-line filter. I don't' say that to be mean, but to let you know that there are differences in in-line filters.

Most filters are made for cars, which have fuel pumps to push the gas through the filter media. Our bikes only have gravity to pull the gas down the few inches from the tank to the carbs, which is not nearly enough to get the gas through some of the filters. The best filters to use for the bikes are ones that are made for gravity-fed gas systems. How do you know, you ask? Easy, just look for a filter for a lawn tractor. Easily found at your "Big Box" home supply store (Lowe's, Home Depot, etc.).

.

[wompin]

Good luck with the in-line filter. I don't' say that to be mean, but to let you know that there are differences in in-line filters.

Most filters are made for cars, which have fuel pumps to push the gas through the filter media. Our bikes only have gravity to pull the gas down the few inches from the tank to the carbs, which is not nearly enough to get the gas through some of the filters. The best filters to use for the bikes are ones that are made for gravity-fed gas systems. How do you know, you ask? Easy, just look for a filter for a lawn tractor. Easily found at your "Big Box" home supply store (Lowe's, Home Depot, etc.).

.

I got a drag sp*cialites brand one from motorcycle s*perstore. Fluid flows with a bit of negative pressure. About the same as it takes to operate the vacuum petcock. Ill be leaving it off for further testing and running gas straight through an axilliary tank hose

[wompin]

Well I wrestled the airbox back in. Took me just short of an hour, which I am quite proud of.

The bike now starts on full choke and runs at about half choke. I think this has to do with the 30 degree F air and air screw settings. I am quite pleased.

Although I feel I have failed by not getting the pods to work, I am tickled to finally have the motor run happily. Now, as long as no further issues come up (knock, knock, knock) with fuel/idle/engine performance, I am off to seal up a few gaskets, pop on a headlight, tailight, and seat, and get the hell out of the garage (as long as the snow holds off a few more days).

If things arent all roses from here on out, you can bet Ill be back to post my frustrations. Thanks all

[BigD_83]

Excellent,

now see what you can do about those Vikings...