Fuel system questions

[Anonymous]

I have a 1985 GS550 that I have a REALLY hard time getting started.

Now, it DOES eventually start after I've nearly killed the battery and sprayed copious amounts of starter fluid into the carb. After that, it runs quite nicely.

I'm just wondering -- what causes this difficulty? Is it the fact that the float bowl on the carb is cold, which chills the gasoline and prevents most of it from vaporizing? If so, could you make it easier to start the bike by just keeping the float bowls warm (i.e. directing a warm-air heater at the carb itself in the garage)?

Another question:
I finished a short motorcycle repair class at the local tech college but I'm still fuzzy on exactly how/why the choke works. My understanding is that the choke actually restricts the air flow through the carb. If that's the case, wouldn't this cause less gas/air mixture to go to the cylinder and make it harder to start the engine? I know I obviously must be wrong because if you leave the choke on once the engine is warm it'll rev right up.

Finally:
What does it mean when an engine is "flooded"? Does that mean there's too much gas/air in the cylinders? If so, why is this bad? I would think that would make it even easier for the engine to start. Or do I just not understand the basics?

Thanks in advance for your answers.

[SqDancerLynn1]

MC choke is an enrichment circuit it alows more fuel to flow to the engine
Conventional auto choke blocks the intake when the mixture is sucked into the engine it draws extra fuel because the air is cut off

How old is your battery?? If it is the least bit weak it could cause problems, have you checked the choke adjustment

[Anonymous]

How old is your battery?? If it is the least bit weak it could cause problems, have you checked the choke adjustment

The battery is new. I just manage to drain it because it takes so long to actually get the engine to start. I'll spray starter fluid in the carb, run the starter for 7-8 seconds and then let the starter rest. It usually takes 6 or 7 repeats of this for the engine to start.

Today, however, this procedure didn't work. I must have tried 10 times. The engine would start up, run long enough to burn off the starter fluid and then die. I checked that the float bowls had fuel in them and all appeared well.

[RacingJake]

Next time I'd check for spark at each cylinder just to make sure it's not an electrical problem, then check your timing. If that all checks good then I'd check flow flow from the tank then go into the carbs.

Many years ago my 1100 had a hard time starting and it was caused by clogged passage in the bowls. The enrichment circuit drawed fuel from this port, couldn't removed the blockage so I drilled it out.

[Mr. Jiggles]

When was the last time the bike was ridden?

[Anonymous]

How old are your plug boots? They break down with time and cause ignition problems and missing. If your battery is new, the boots are the next thing to check.

Kim
I did a major at MIt in plug boots. :-)

[Anonymous]

Thanks for all the replies!

I've removed each spark plug and confirmed a blue spark on each one. It would appear there is no problem with the ignition system.

I've removed the carburetor and will take it apart and clean it (again!) today.

[Anonymous]

In my carburetor when u turn on the choke it alows the vacuum being created to flow to the top of the rubber diaphram on the carb, doesnt this open the jet and make more fuel flow........and my bike doesnt rev up when i put on the choke it just idles rough or stalls.. when its warm......I know when you restrict the air the vacuum will suck up gas from the bown but howcome theres this passagway to the diaphram?

[Anonymous]

Sounds like it is time to clean the carbs.