Starting on One Cylinder

[needlongerlegs]

Hi Peeps,

I've got a 1991 R100 thats giving me grief,

Starting from Cold it always fires up on one cylinder,

After a few seconds the second pot chimes in,

I've rebuilt carbs, checked chokes ect,

Repaced plugs and checked all connections,

An I missing something

Hellllp NNL

 

[bumpmuncher]

have you tried a kettle of boiling water over the carb on the side its slow firing up on

 

[(RIP) maverick]

have you tried a kettle of boiling water over the carb on the side its slow firing up on

Yes and it works every time, problem is finding a kettle of boiling water if I stop somewhere away from home

I rebuilt my carbs recently with all o-rings/diaphrams and made sure every single hole is open. Then made sure the choke assembly is the right way around.

It now starts easier and on both cylinders.

 

[Timpo]

It now starts easier and on both cylinders.

Maverick, would you say it's fixed it or just 'easier' but still a worry to start?
NLL, have you made any further progress, as my R100 is doing the same. The l/h pot won't fire up without a struggle.

Timpo.

 

[needlongerlegs]

Nope, Getting Depressed now,

I'm about to set fire to it,

Carbs Cleaned again and rebuilt all new jets, and diaphrams etc,

Have check choke function by lifting arms both cylinder stall about the same if chokes are lifted

New Plugs and Leads, I removed coil cleaned it up all looks good,

Bloody thing still starts on one and then second one chimes in,

Could it be coil?

Needlongerlegs
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[DrFarkoff]

try turning off both taps When you park up?

 

[Les Rice]

re Starting on one cylinder

Ive just had tis same problem with my 1991 R100GS.
I did loads of stuff to try and sort this problem, but the thing that sorted it was to replace the choke disks with "old type disks" as they have four holes in them whereas the newer type disks such as the ones that I suspect you have on your bike only have two holes, so it stands to reason that you get a more progressive choke action with the old type disks.

Hi Peeps,

I've got a 1991 R100 thats giving me grief,

Starting from Cold it always fires up on one cylinder,

After a few seconds the second pot chimes in,

I've rebuilt carbs, checked chokes ect,

Repaced plugs and checked all connections,

An I missing something

Hellllp NNL

 

[ChasF]

On my bike it was one of the early signs of the coil breaking down.

Defies logic, I know, as the coil fires both cylinders but once I changed the coil the starting on one cylinder and various other traits disappeared

 

[Beemerboff]

Mine only does that when I forget to turn the petrol on - have you pulled the float bows off and checked that when you turn one tap on you get a good flow of gas at both carbs?

 

[Redboots]

OK, I give in. What is it with the boiling water on the carbs

Is it to do with the floats?


John

 

[bumpmuncher]

I am not entirely sure. I think It is something to do with the choke disks ? (or something in the cold start system) a sign of worn parts or incorrectly assembled carb. It seems to be becomming the airhead version of the displaced throttle cable outers problem that seems to occur regualy for first time tank removal from an 11XX.

My bike can be a bit slow starting on very cold mornings. both pots equally slow to fire up. this morning I tried a kettle of boiling water over both carbs and it started almost the instant I pressed the button so thinking my carbs could be getting a little worn so it maybe be an idea to rebuild the carbs intime for next winter. But you know what they say about assumptions

 

[(RIP) maverick]

Maverick, would you say it's fixed it or just 'easier' but still a worry to start?
NLL, have you made any further progress, as my R100 is doing the same. The l/h pot won't fire up without a struggle.

Timpo.

Hi Timpo,

It is sorted now and fires up easy. Haven't had that sub zero conditions of December again and that would be the ultimate test. There is a little o-ring on the choke body shaft which needs to be checked as well. Mine was well knackered and think the choke did not close fully some times either hence struggling to get it idling properly when hot.

It now fires up and idles just touching 1150 rpm when nice and hot. I can set it slower but hate that bloody little red alternator light flickering

 

[needlongerlegs]

On my bike it was one of the early signs of the coil breaking down.

Defies logic, I know, as the coil fires both cylinders but once I changed the coil the starting on one cylinder and various other traits disappeared

You know I'm thinking exactly the same, double checked everything today,

Cleaned choke circuits again, eveything looks fine,

Choke on full, hit button catch it on one gentle rev and in comes pot two dooooooooh, then all is fine, and only dos this from cold

B*****dy Thing LOL

And its the left Pot.....Timpo....

NLL

 

[needlongerlegs]

Swopped Sides

Yup just run down to workshop and checked again nothing changed and it fired up on left hand side this time....Coil Ordered NLL

 

[Timpo]

Hi Timpo,

It is sorted now and fires up easy. Haven't had that sub zero conditions of December again and that would be the ultimate test. There is a little o-ring on the choke body shaft which needs to be checked as well. Mine was well knackered and think the choke did not close fully some times either hence struggling to get it idling properly when hot.

It now fires up and idles just touching 1150 rpm when nice and hot. I can set it slower but hate that bloody little red alternator light flickering

This sounds promising... I'll be on it at the weekend.

Thanks.

T.

 

[Mike the Bike]

Yup just run down to workshop and checked again nothing changed and it fired up on left hand side this time....Coil Ordered NLL

I know this sounds like a dumb question, but how do you know if its the left or right side thats firing ? It all just sounds like a struggling engine to me

 

[ChasF]

I know this sounds like a dumb question, but how do you know if its the left or right side thats firing ? It all just sounds like a struggling engine to me

Touch the exhaust headers

 

[Timpo]

Touch the exhaust headers

I often wonder how some people get their usernames?

 

[Mike the Bike]

Thanks ChasF

Mike the Bike - Mike Hailwood's nickname, and it rhymes, and my name's Mike

 

[needlongerlegs]

Touch the exhaust headers

Yup, b****y thing is random, first couple of times it fired up on one side then couple of hours later it will be other side, pain is once its fired up once its fine, so have to leave it couple of hours before trying again, coil should be here tomorrow so we'll see, NLL