Making a Temporary Tank?

[Pelikan]

I'm going to be rejetting soon, and will want to sync the carbs after.  According to Haynes and elsewhere, I need to make a temporary fuel tank.  Poked around a bit, didn't see anything.

What do you guys do when you need a temp tank?  I imagine it involves getting some vessel that holds gas and adding a barb/valve that fits the fuel hose...but I want to make sure I'm getting the right stuff first time out.

[Twisted]

Plastic soda bottle

[burning1]

I usually just stick a large 2-stroke oil pre-mix syringe in the end of a length of fuel hose, and use a liter size bottle of gas to fill it. Volume is large enough to idle the bike for a few minutes.

[Suzuki Stevo]

A piece of Tygon tubing slipped over the fuel hose (1/2 ID 5/8 OD is quite common and is what I use). You can slip the Tygon tube over the fuel line an inch or so, then add a funnel to the other end, Ny-Tie it to the bike, Ninja 250R shown.. I use the same hose and funnel for the GS500, it doesn't leak a drop. Transfer the fuel to a small controllable container before you start, you don't want to try and fill that funnel with a 5 Gal can..you might spill gas all over.




See the fuel just below this text


I threw this photo in just because...

[Paulcet]

 I used a  generic radiator overflow tank from the auto parts store. It has a few mounting holes on it, so its easy to Ny-tie it any where.

[The Buddha]

You can run a long fuel line set to the stock tank which you can place next to the bike on a table.
You can also synch it by eyeball, vacuum isn't neccesary, the eyeball is accurate enough.
Cool.
Buddha.

[tb0lt]

I use an empty 1 gallon milk container turned upside down with a brass air nipple threaded into the cap (also threaded).

[Suzuki Stevo]

vacuum isn't neccesary, the eyeball is accurate enough.
Cool.
Buddha.

You'll have a hard time convincing me of that. If it was true I would only have to sync a bike once and then forget about syncing ever again. I check all my bikes that have more than one piston at the start of every season, and they are always off. Eyeballing will get you in the ballpark and that's all, good mechanics know that you set the valve lash first and then perform a carb/TB sync.....there is a reason for this. dynamic tuning will always trump static eyeballing anyday. IMHO

[scratch]

I just use a 4x4 under the back end of the tank, and a short screwdriver.  But, I don't know if that can be done with the '00 or newer models.

[gearman]

I stopped by the local mower repair shop and picked up one off of a push mower for $3.

[the mole]

Temporary tank:




You can make one very quickly with one of these:

[Pelikan]

^^^ Awesome!!  You think I can trade my GS in on one of those?

[Porkchop]

I use the gas tank off of my lawn mower when I need a temp tank.  I just have to remember to put it back on the mower when the weather warms up.

-Porkchop

[The Buddha]

vacuum isn't neccesary, the eyeball is accurate enough.
Cool.
Buddha.

You'll have a hard time convincing me of that. If it was true I would only have to sync a bike once and then forget about syncing ever again. I check all my bikes that have more than one piston at the start of every season, and they are always off. Eyeballing will get you in the ballpark and that's all, good mechanics know that you set the valve lash first and then perform a carb/TB sync.....there is a reason for this. dynamic tuning will always trump static eyeballing anyday. IMHO

The thing actually moves with the vibration etc ... not a whole lot but a wee bit.
Of course setting the thing with engne vacuum means if the vacuum changes you're synch is off. The other thing is the bike can well make more vacuum in 1 cyl @ idle but lose it faster with rising rpm. You can also have valve gap change and have it change the synch. I'd seriously say the vacuum method is no better than eyeball, however eyeball requires you to remove the carbs completely which is a PITA, if you synch by eyeball and end up with a very buzzy bike that is a symptom some serious is off in the motor.
The corollary to that was my 48K mile 89, which through much of its last few years (35K on) would vibrate a lot @ idle only to go buttery smooth ~3500. Weird, but I can see how a vacuum synch would have messed that whole thing ... or not. Past 1/4 throttle it matters little.
Cool.
Buddha.

[tt_four]

I made a nice bottle last spring. i took some pictures and posted them here, but I don't think they're on my flickr page anymore so they'd just be little red Xs by now. I took a think plastic bottle, something like a gatorade bottle, bought some fittings from the plumbing/aircompressor department of home depot with some rubber washers. Screwed them into the lid.

Just for creative points, I also took one of those skinny valves from a bicycle presta tube, cut it out of the inner tube, drilled another hole in the bottom of the bottle, tightened that in with the little nut that came with it, and then put some gorilla glue around the outside. That way air can flow into the bottle easily so the gas doesn't have to deal with a vacuum trying to come out the other end. When I'm done I just screw the valve shut.

[Suzuki Stevo]

vacuum isn't neccesary, the eyeball is accurate enough.
Cool.
Buddha.

You'll have a hard time convincing me of that. If it was true I would only have to sync a bike once and then forget about syncing ever again. I check all my bikes that have more than one piston at the start of every season, and they are always off. Eyeballing will get you in the ballpark and that's all, good mechanics know that you set the valve lash first and then perform a carb/TB sync.....there is a reason for this. dynamic tuning will always trump static eyeballing anyday. IMHO

The thing actually moves with the vibration etc ... not a whole lot but a wee bit.
Of course setting the thing with engne vacuum means if the vacuum changes you're synch is off. The other thing is the bike can well make more vacuum in 1 cyl @ idle but lose it faster with rising rpm. You can also have valve gap change and have it change the synch. I'd seriously say the vacuum method is no better than eyeball, however eyeball requires you to remove the carbs completely which is a PITA, if you synch by eyeball and end up with a very buzzy bike that is a symptom some serious is off in the motor.
The corollary to that was my 48K mile 89, which through much of its last few years (35K on) would vibrate a lot @ idle only to go buttery smooth ~3500. Weird, but I can see how a vacuum synch would have messed that whole thing ... or not. Past 1/4 throttle it matters little.
Cool.
Buddha.

Syncing makes the cylinders work together as a team, right off an idle, the farther you get from an idle, the less it matters. But it does matter enough to do it correctly with a manometer. My Carb Stik is 33 years old, look at the hoses, I am the original owner....trust me, it matters. I have never had a customer come back after a carb sync and say that their bike didn't run better or smoother...quite the contrary.

The big variable in the equation is the big fuel/Air pump in front of the carbs that we call the engine, the exhaust system is a variable, valve lash is a variable, state of tune is a variable, mileage is a variable, you sync because of all of the variables that just setting the butterfly's the same doesn't accomplish . The second you rotate the throttle off an idle you need both cylinders pulling as a team, this is where syncing shows it's worth. If you don't mind a stumble or a hesitation, don't worry about about the carb balance/sync. My point is with all the variables the engine poses to the process of syncing, expecting to eyeball or even use drill stock as a measuring device to set the carbs, if your not using a manometer..your just getting a ballpark setting.  

If you race..no big, the transition from idle to partial throttle is no big thing, you have it WFO anyway.

EDIT: Let's just say that I put allot of value on a good carb/TB sync and you...not so much?  

[the mole]

^^^ Awesome!!  You think I can trade my GS in on one of those?

Sure, and its just as good as a bike at getting through the traffic.

[The Buddha]

vacuum isn't neccesary, the eyeball is accurate enough.
Cool.
Buddha.

You'll have a hard time convincing me of that. If it was true I would only have to sync a bike once and then forget about syncing ever again. I check all my bikes that have more than one piston at the start of every season, and they are always off. Eyeballing will get you in the ballpark and that's all, good mechanics know that you set the valve lash first and then perform a carb/TB sync.....there is a reason for this. dynamic tuning will always trump static eyeballing anyday. IMHO

The thing actually moves with the vibration etc ... not a whole lot but a wee bit.
Of course setting the thing with engne vacuum means if the vacuum changes you're synch is off. The other thing is the bike can well make more vacuum in 1 cyl @ idle but lose it faster with rising rpm. You can also have valve gap change and have it change the synch. I'd seriously say the vacuum method is no better than eyeball, however eyeball requires you to remove the carbs completely which is a PITA, if you synch by eyeball and end up with a very buzzy bike that is a symptom some serious is off in the motor.
The corollary to that was my 48K mile 89, which through much of its last few years (35K on) would vibrate a lot @ idle only to go buttery smooth ~3500. Weird, but I can see how a vacuum synch would have messed that whole thing ... or not. Past 1/4 throttle it matters little.
Cool.
Buddha.

Syncing makes the cylinders work together as a team, right off an idle, the farther you get from an idle, the less it matters. But it does matter enough to do it correctly with a manometer. My Carb Stik is 33 years old, look at the hoses, I am the original owner....trust me, it matters. I have never had a customer come back after a carb sync and say that their bike didn't run better or smoother...quite the contrary.

The big variable in the equation is the big fuel/Air pump in front of the carbs that we call the engine, the exhaust system is a variable, valve lash is a variable, state of tune is a variable, mileage is a variable, you sync because of all of the variables that just setting the butterfly's the same doesn't accomplish . The second you rotate the throttle off an idle you need both cylinders pulling as a team, this is where syncing shows it's worth. If you don't mind a stumble or a hesitation, don't worry about about the carb balance/sync. My point is with all the variables the engine poses to the process of syncing, expecting to eyeball or even use drill stock as a measuring device to set the carbs, if your not using a manometer..your just getting a ballpark setting.  

If you race..no big, the transition from idle to partial throttle is no big thing, you have it WFO anyway.

EDIT: Let's just say that I put allot of value on a good carb/TB sync and you...not so much?  

OK this is a bit too precise for a GS, or any 80's bike. You really should do a eyeball synch and compare how far you're off from your vacuum method.
I do eyeball for every carb that comes to me ... 2 reasons for that - 1 I dont have their engine so I cant vacuum synch, 2. Fitting it on a bike and getting the rest of the parameters (pipe or air filter etc ) matched is probably an hour of work which I dont have to charge my customer for.

A vacuum synch may be better except in the most uneven bike where the 2 cyls are too far off, but an eyeball synch will work almost as well in all bikes. You have to remember the 2 cyls dont have nearly the same flow rate, the 4 cyls are even worse where the outers are nearly 10% off from the middle ones.
If you want to measure the distance between NY and LA - you dont have to be accurate to the nearest millimeter. An eyeball synch will eliminate the carb uneven ness from engine problems. If you synch to the engine, you would get 2 uneven carbs that would cover the engines problems till it gets to ~3k, where it would start acting up and you could have trouble detecting it for a while.
Cool.
Buddha.

[Suzuki Stevo]

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