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hard to start

  • Thread starter Thread starter mordantmonkey
  • Start date Start date
HAHA, electric start... my legs will be begging me to get that working soon.
which reminds me of two more questions if anyone could answer.

one, seems that the starter is ok, but i'm not getting enough juice from the battery to start the engine. it'll do a half turn and then just click the next time i try the electric start. could it just be that i don't have enough cranking amps on the battery?

two, in the VM carb rebuild guide it says i need a set of o-rings, but that i should also buy OEM suzuki "o-rings for carb/cylinder head boots". that's part 09280-28003, right? or does he mean 09402-42306? they should be visible in this link http://www.flatoutmotorcycles.com/f...y=Motorcycles&make=Suzuki&year=1979&fveh=2106
 
(Good question, Mike!) Without knowing what has been tried already it's hard to point you in a particular direction...

Having said that, there IS one thing that I recently learned almost universally helps our Suzis start when they're cold ... that is switching the petcock to "prime" and allowing the float bowls to refill with fuel (when the bikes sit the bowls can empty). This little gem has proven VERY useful to me and others. ALWAYS put the bike on full choke and NEVER twist the throttle when it's cold.

One more thing ... DON'T FORGET TO SWITCH THE PETCOCK BACK TO "RUN" AFTER IT STARTS!!!!! If you don't switch it back the engine will get too much fuel, run poorly, and after you shut it down the excess fuel could leak into the crankcase and contaminate the oil.

If the bike is still problematic using this strategy you'll definitely need to look into carb cleaning, electrical/ignition issues, or a combination of both...

Good Luck with it!
There is a lot of misunderstanding about the "prime" petcock position. The engine will NOT get too much fuel, OR run poorly!
This prime position is the same as the "ON" position of a non-vacuum operated petcock, such as used on 80's Hondas.
The only reason for the vacuum petcock is that the rider doesn't have to remember to turn it off after a ride.
The only way excess fuel can get through is if the float needle valves in the carbs are leaking.:?
 
HAHA, electric start... my legs will be begging me to get that working soon.
which reminds me of two more questions if anyone could answer.

one, seems that the starter is ok, but i'm not getting enough juice from the battery to start the engine. it'll do a half turn and then just click the next time i try the electric start. could it just be that i don't have enough cranking amps on the battery?

two, in the VM carb rebuild guide it says i need a set of o-rings, but that i should also buy OEM suzuki "o-rings for carb/cylinder head boots". that's part 09280-28003, right? or does he mean 09402-42306? they should be visible in this link http://www.flatoutmotorcycles.com/f...y=Motorcycles&make=Suzuki&year=1979&fveh=2106

Item 22 is the o-rings you will need and www.cycleorings.com is where you want to order the ones to rebuild your carbs.If you order your o-ring for the boot (item 22) from the dealer you wont have to pay shipping.Also a good sight for parts is www.bikebandit.com.Also,have you tried charging your battery? Is it the right one for the bike? Advanced auto or any parts store will be able to look up your bike and tell you what battery you are suppose to have.If its been sitting for a couple of years the battery is probably no good.
 
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thanks. oh and thanks for the suggestion on motorcyclecloseouts. got a great deal on my gear.

the battery looks like a cheapo with only a one year guarantee so i'm thinking it just doesn't have enough power, but i'll try to give it a full charge this weekend. but i don't mind the kickstarting for now.
 
thanks. oh and thanks for the suggestion on motorcyclecloseouts. got a great deal on my gear.

the battery looks like a cheapo with only a one year guarantee so i'm thinking it just doesn't have enough power, but i'll try to give it a full charge this weekend. but i don't mind the kickstarting for now.
Its a good place to shop! Use only distilled water in your battery.You should replace it asap cause a bad battery will cause problems with your electricals.It most cases of buying old vehicles or bikes a new battery would be the first thing to buy.You could take it to the auto parts store and have it tested.I also replace my fuel line with polyurethane clear or blue line so I can see the fuel going in when i turn the prime on after it has been sitting for a few days.Most dealers have it.Its only a buck a foot and does not require clamps.i always have a couple of foot of it lying around in 1/4 and 5/16th's if you want to try some.I use 1/4" for mine and I do run an in-line filter.There are lots of pro's and con's on filters.I have had no problems with mine though,as long as they sit vertical and not horizontal you should be ok.Do you know how to adjust your clutch cable?If not I can scan my clymers manual and send it to you via e-mail on how to do that.It's easy.
 
There is a lot of misunderstanding about the "prime" petcock position. The engine will NOT get too much fuel, OR run poorly!
This prime position is the same as the "ON" position of a non-vacuum operated petcock, such as used on 80's Hondas.
The only reason for the vacuum petcock is that the rider doesn't have to remember to turn it off after a ride.
The only way excess fuel can get through is if the float needle valves in the carbs are leaking.:?

Allow me to correct you on this and it comes from personal experience ... if you leave the petcock on "Prime" a 1983 GS1100G (and presumably some of the other models, if not all) WILL get too much fuel AND run VERY poorly.

I know this because of an unhappy experience about two years ago when Skreemer and I were headed down to the Brown County Rally. Skreemer and Nerobro came over a week earlier to do a carb clean with me on my then "new to me" 1983 1100G, and when the bike was reassembled Nerobro switched the petcock to "prime" without my knowing it. He forgot to switch it back, and since my other bike is a 1980 GS550L with the leverless petcock (ALL '80 GS's had this) it never occured to me to even look at the petcock before we set off.

The bike seemed to run normally at lower speeds, but when we got over about 45mph the engine bogged badly and ran VERY rough. We initially thought a plug wire was loose, and we stopped several times to try and narrow down the problem. It was only after an hour and a half on the road that it dawned on both of us to check the petcock setting.

Sure enough, switched it back to "run," let the vacuum pressure control the flow, and the bike again ran FLAWLESSLY. If I had problems with leaking float needle valves I would not only expect the bike to continue to run poorly regardless of petcock setting, but also to get very poor fuel mileage, which isn't the case. Even with a fully dressed bike ridden in a "spirited" fashion my mileage seems to be on par with the norm for an 1100.

So again, DON'T FORGET TO SWITCH THE PETCOCK BACK TO "RUN" OR YOU MORE THAN LIKELY WILL EXPERIENCE PROBLEMS DUE TO TOO MUCH FUEL FLOW...

Regards,
 
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Allow me to correct you on this and it comes from personal experience ... if you leave the petcock on "Prime" a 1983 GS1100G (and presumably some of the other models, if not all) WILL get too much fuel AND run VERY poorly.

I know this because of an unhappy experience about two years ago when Skreemer and I were headed down to the Brown County Rally. Skreemer and Nerobro came over a week earlier to do a carb clean with me on my then "new to me" 1983 1100G, and when the bike was reassembled Nerobro switched the petcock to "prime" without my knowing it. He forgot to switch it back, and since my other bike is a 1980 GS550L with the leverless petcock (ALL '80 GS's had this) it never occured to me to even look at the petcock before we set off.

The bike seemed to run normally at lower speeds, but when we got over about 45mph the engine bogged badly and ran VERY rough. We initially thought a plug wire was loose, and we stopped several times to try and narrow down the problem. It was only after an hour and a half on the road that it dawned on both of us to check the petcock setting.

Sure enough, switched it back to "run," let the vacuum pressure control the flow, and the bike again ran FLAWLESSLY. If I had problems with leaking float needle valves I would not only expect the bike to continue to run poorly regardless of petcock setting, but also to get very poor fuel mileage, which isn't the case. Even with a fully dressed bike ridden in a "spirited" fashion my mileage seems to be on par with the norm for an 1100.

So again, DON'T FORGET TO SWITCH THE PETCOCK BACK TO "RUN" OR YOU MORE THAN LIKELY WILL EXPERIENCE PROBLEMS DUE TO TOO MUCH FUEL FLOW...

Regards,

I agree with you on that.I also left my petcock on prime and rode off.2 miles later she's started bogging down and sluggish on idle.I reached down and put it on the "on" position and it straightend right up.Just last week I put a new fuel line on and it "purged" my carbs when i tried to prime it and some gas went in the air box.My guess is the gas going in the new fuel line created a "wave" action cause the bowls were already full and the gas followed the path of least resistance, sort of like overfilling a glass.Nest time I put on a new fuel line I will drain at least one carb bowl to allow for the fuel flow.
 
I agree with you on that.I also left my petcock on prime and rode off.2 miles later she's started bogging down and sluggish on idle.I reached down and put it on the "on" position and it straightend right up.Just last week I put a new fuel line on and it "purged" my carbs when i tried to prime it and some gas went in the air box.My guess is the gas going in the new fuel line created a "wave" action cause the bowls were already full and the gas followed the path of least resistance, sort of like overfilling a glass.Nest time I put on a new fuel line I will drain at least one carb bowl to allow for the fuel flow.

Before I attempted to kiss a guardrail, my bike ran fine on either "ON" or "PRIME."

I'm thinking that if your bike runs different on "PRIME" then you've got a petcock problem, or it's sucking in crap from lower in your tank. Shouldn't the carbs only pull so much fuel if they're in working order, regardless of petcock setting?
 
Before I attempted to kiss a guardrail, my bike ran fine on either "ON" or "PRIME."

I'm thinking that if your bike runs different on "PRIME" then you've got a petcock problem, or it's sucking in crap from lower in your tank. Shouldn't the carbs only pull so much fuel if they're in working order, regardless of petcock setting?
yes, if they're in working order you could run a line from the tank to the carbs and have no petcock and it will make no difference, which is what the prime position does.
 
Before I attempted to kiss a guardrail, my bike ran fine on either "ON" or "PRIME."

I'm thinking that if your bike runs different on "PRIME" then you've got a petcock problem, or it's sucking in crap from lower in your tank. Shouldn't the carbs only pull so much fuel if they're in working order, regardless of petcock setting?

Ditto here -- no difference between prime and on on my bike.

Since vacuum isn't actually pumping the gas, only actuating a valve to allow gas to flow, and since a properly working petcock/vacuum hose/vacuum port should always have enough vacuum to be actuated when the engine is on, there shouldn't be any difference that I can see when the bike is *running* between prime and on. When the bike is off, though, if gas is leaking past your float needles, you'll have a problem.

Perhaps for the people whose bikes run differently between prime and on there is an issue with float height *and* petcock? If the float height were too high and the petcock wasn't flowing as well (diaphragm not moving freely?) on "on", maybe the restricted gas flow would compensate or something? Ok maybe that's far-fetched but there has to be some explanation... ;-)
 
Ditto here -- no difference between prime and on on my bike.

Since vacuum isn't actually pumping the gas, only actuating a valve to allow gas to flow, and since a properly working petcock/vacuum hose/vacuum port should always have enough vacuum to be actuated when the engine is on, there shouldn't be any difference that I can see when the bike is *running* between prime and on. When the bike is off, though, if gas is leaking past your float needles, you'll have a problem.

Perhaps for the people whose bikes run differently between prime and on there is an issue with float height *and* petcock? If the float height were too high and the petcock wasn't flowing as well (diaphragm not moving freely?) on "on", maybe the restricted gas flow would compensate or something? Ok maybe that's far-fetched but there has to be some explanation... ;-)

I know that my petcock is working fine ,but Im not a carb guru,I wish i was! The next time I go riding I will put it on prime and see if there is a difference and report back.I do get 58 to 60 mpg.and everthing seems to be in working order.I do run an inline filter.That might have something to do with it.
 
Thanks for your contributions, guys.
The simple fact remains that the engine should run exactly the some on "On" or "Prime"
If it doesn't, there is something wrong, it's as simple as that!
Just for the record, I have owned 5 Suzukis and they all ran identical regardless of which was used.
 
Thanks for your contributions, guys.
The simple fact remains that the engine should run exactly the same on "On" or "Prime"
If it doesn't, there is something wrong, it's as simple as that!
Just for the record, I have owned 5 Suzukis and they all ran identical regardless of which was used.

In theory I would agree with you that there shouldn't be a difference between the two settings ... and yet there is.

I know the carb is clean and I know that it performs efficiently ... and since there are absolutely no adverse performance issues there is absolutely no reason to go searching for a problem that functionally doesn't exist.

By the way, many others have stated that if the petcock is left on "prime" when the bike isn't being ridden that excess fuel will contaminate the oil, so regardless of whether there is a difference during running I would be extremely wary of leaving a petcock on "prime" and risk destroying the motor through oil contamination. I'm not a carb guru either, so I don't know the "whys" relating to these issues. Only that for whatever reason there does seem to be a difference for a lot of people.

Regards,
 
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In theory I would agree with you that there shouldn't be a difference between the two settings ... and yet there is.

I know the carb is clean and I know that it performs efficiently ... and since there are absolutely no adverse performance issues there is absolutely no reason to go searching for a problem that functionally doesn't exist.

By the way, many others have stated that if the petcock is left on "prime" when the bike isn't being ridden that excess fuel will contaminate the oil, so regardless of whether there is a difference during running I would be extremely wary of leaving a petcock on "prime" and risk destroying the motor through oil contamination. I'm not a carb guru either, so I don't know the "whys" relating to these issues. Only that for whatever reason there does seem to be a difference for a lot of people.

Regards,

Gas should only get into the oil if your floatneedle o-rings leak.
 
Gas should only get into the oil if your floatneedle o-rings leak.

That may be, but is that a risk you want to take when it can be so easily avoided??

Oh, and incidentally, mine would appear to be just fine. How do I know? Because the bike sat on "prime" for a week before the Brown County Rally that year, and not only DIDN'T I see any leaking fuel outside the bike, but the oil never smelled of gas, nor did it appear contaminated when it was changed ... and I haven't suffered any catastrophic engine damage almost two years after this happened...
 
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Gas should only get into the oil if your floatneedle o-rings leak.
I just went for a ride and found no difference in on or prime while running.HOWEVER,i will not risk leaving my petcock on prime while sitting or not riding.I have never had gas in my oil and dont want to know what it's like if it does happen this way.Why do some people get gas in the airbox?I had that happen last week when I changed fuel lines.I wiped it out and cleaned my filter and everything is fine now,but what makes that happen?
 
I'm not advocating leaving your petcock on PRIME.
I know you wouldnt do that.Ive just heard so many horror stories of gas filled crancases that I always make sure that once the gas fills the line to the petcock I turn it back to "on".I have a urethane fuel line that I can see threw. I just wish i had a spare set of carbs to disect and learn more about then I wouldnt be so paranoid about taking my good ones apart.Mine seem fine but Im sure they could use a good cleaning.
 
When I first got my bike there was lots of gas in the oil because the float valve o-rings were shot. Since I replaced them, no amount of leaving it on prime will have any adverse affects. The vacuum petcock is an extra layer of protection against that, though, so leaving it on "on" is definitely what you want to do. You never know when you'll get a stuck float or an o-ring will go out again.

Incidentally gas in the oil does not mean certain death for your motor. It means the oil's capacity to lubricate has been diminished and you risk excessive wear. Over time that may mean engine failure, but not if you catch it within a reasonable amount of miles. Just keep an eye on oil level and smell.
 
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