Rebuilt carbs #1 not firing.

[pvasc]

This is not a drain. This is a vent. If you see gas coming out of these, you definitely have a stuck float, bad petcock, or both. And you'll have gas in other places it's not supposed to be.

I had a feeling that was what it was. I was at a loss to describe it so I went to Babbits fiche for nomenclature. I will get a new one, this one is hard.

[pvasc]

So here is what I see to be the theme or cause of my problem. I fail to drain the carbs. Why? It is a pain in the butt and messy. I am a previous Honda owner they had nice drains with hoses that I could easily drain. The 850, I have to cram something under the carbs then try to reach the drain plugs of 2 and 3, gas goes everywhere. Tried my Harley oil filter drain without success, going to try a small bread pan. Maybe a flexible cutting board to funnel the fuel to a container? Last time I gave up and put a shop towel on the engine and let the drains go.

[Rich82GS750TZ]

I had a feeling that was what it was. I was at a loss to describe it so I went to Babbits fiche for nomenclature. I will get a new one, this one is hard.

Just to be clear, your carbs have 2 vent hoses, just get both.
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[allojohn]

And you'll have gas in other places it's not supposed to be.

Just making sure you didn't miss this pvasc.... you could have gas in your crankcase.

[pvasc]

Just making sure you didn't miss this pvasc.... you could have gas in your crankcase.

I could, I don't smell it though. It happened before when the petcock failed. New petcock 2007ish.

[greg78gs750]

tuna can is close to the right size for getting into those drain screws, for next time

[pvasc]

Just to be clear, your carbs have 2 vent hoses, just get both.
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I can't get the screen shot to post. Those hoses are ok. Look at the airbox fiche just above the carb one part #11.

[pvasc]

tuna can is close to the right size for getting into those drain screws, for next time

Thanks. That will make things easier. Never thought of a tuna / cat food can. I have cats so plenty of cans.

[pvasc]

Well I been playing. Carbs on, no airbox, still running on 3. Swapped slides 1 and 4. I know it won't run well without the airbox, but I can see if a carb is flooding. So now it is sitting aux tank installed and a half gallon of fuel for head pressure. I will look in a bit to see where the fuel is coming out. I did notice fuel coming out of the main system hole, (bottom right), on #2 a running cylinder, but then I had been spraying cleaner and starting fluid. It looks like I will not be able to escape performing the full monty this time.

[Rich82GS750TZ]

I can't get the screen shot to post. Those hoses are ok. Look at the airbox fiche just above the carb one part #11.

We're talking about different things here. The hose #11 and #12 on the airbox fiche are drain hoses for the airbox and they do not/should not connect to your carbs, they go to ground between the rear of the engine and swing-arm.


The 2 carb vent hoses route over the airbox, i think on just about all GS models, under the seat and are just open to air.

[pvasc]

We're talking about different things here. The hose #11 and #12 on the airbox fiche are drain hoses for the airbox and they do not/should not connect to your carbs, they go to ground between the rear of the engine and swing-arm.


The 2 carb vent hoses route over the airbox, i think on just about all GS models, under the seat and are just open to air.

Exactly the hose I am talking about. I know they don't go to the carbs. I have read about how critical it is to have a well sealed airbox. This hose attaches to the upper chamber...I think. My question is would that cause problems if it was in the air box but not in the place where it is supposed to be. Or am I wrong and it mounts to the bottom of the airbox? However that hole is too big. Or is it insignificant?

[Rich82GS750TZ]

That I do not know. Sorry

[pvasc]

So, I did spray the intake boot with starting fluid, the red straw did not fit the can nozzle. Just went out to check for leaks / overflow, #4 was a little wet. Fired it up and again with the fluid of start this time as precise as possible I aimed at the connection to the cylinder head. You would have thought the o-ring went bad just sitting. Idle went up, exhaust temp went up. Double checked with carb cleaner, same, not as good, but same results. Sprayed starting fluid down carb, nothing, in pilot jet hole, and idle went up.
It will be a week or so before I can post results, replacing all o-rings and screws.

Thank-you all for your input.

[Steve]

First, do your bike a favor and throw the starting fluid AWAY.

Not sure why you feel the need to drain the carbs. If it's for storage, just add some fuel conditioner to the tank, go for a short ride to make sure it's gotten through all the carb circuits then park the bike.

If you are going to remove the carbs for work, just remove them. You can leave them mostly upright without losing any fuel until they are put back on the bike. If you need to remove the bowls, it is easy enough to hold them over a pan for draining.

.

[pvasc]

First, do your bike a favor and throw the starting fluid AWAY.

Not sure why you feel the need to drain the carbs. If it's for storage, just add some fuel conditioner to the tank, go for a short ride to make sure it's gotten through all the carb circuits then park the bike.

If you are going to remove the carbs for work, just remove them. You can leave them mostly upright without losing any fuel until they are put back on the bike. If you need to remove the bowls, it is easy enough to hold them over a pan for draining.


.

It is an old winter storage habit from the days before Stabil, and when Stabil would dissolved plastic floats. I did put stabil in the tank, but didn't run it through, (bike wasn't running well enough) the gas that came out of the carbs was Mountain Dew colored.

Toss the starting fluid. I agree. But sometimes, and this comes and goes, it won't start and I hate grinding on the starter. Right this minute, it starts right off, this is even with the airbox off, and 3 cylinders that run.

Is Stabil 360 a good conditioner for storage? Anything to keep from draining the carbs.