Non-MG bike question ( ZX12R Choke lever stuck )

[MotoGuzzi750]

( Sorry about posting here, since its not about MG bike, not sure how terribly out of place this is, but I thought I will ask anyways )

Choke lever/cable on Kawi zx12r was working normally, until one morning it stopped moving from its choke-OFF position.
I don't remember anything was wrong with choke cable/lever before it stopped moving.

Anyone with any experience/ideas ?

Thanks in advance !

[Ncdan]

( Sorry about posting here, since its not about MG bike, not sure how terribly out of place this is, but I thought I will ask anyways )

Choke lever/cable on Kawi zx12r was working normally, until one morning it stopped moving from its choke-OFF position.
I don't remember anything was wrong with choke cable/lever before it stopped moving.

Anyone with any experience/ideas ?

Thanks in advance !

Any motorcycle conversation or inquiries are welcome.
Someone will probably be along shortly to help you out👍


Dan

[Kev m]

Interesting bike - so it's a 4-throttle body EFI setup with a "choke" cable (I'm assuming that's a fast idle lever in reality that works on the synchronized throttle linkage?).

What have you checked so far?

Condition of lever, cable (including routing, look for kinks or damage), and where it attaches on the linkage.

The throttle is working normally opening and closing smoothly? If it is, and I'm right that it's a fast idle lever, then something must be binding mechanically on the lever/cable/linkage.

[rschrum]

Mine came to me not working, froze up. Turned out to be the cable and no amount of lube or persuasion would budge it. Found a good used one on ebay.

[MotoGuzzi750]

Interesting bike - so it's a 4-throttle body EFI setup with a "choke" cable (I'm assuming that's a fast idle lever in reality that works on the synchronized throttle linkage?).

What have you checked so far?

Condition of lever, cable (including routing, look for kinks or damage), and where it attaches on the linkage.

The throttle is working normally opening and closing smoothly? If it is, and I'm right that it's a fast idle lever, then something must be binding mechanically on the lever/cable/linkage.

I have not checked anything yet. Throttle works normally.. and I actually drive the bike without any issues.
( Only issue is starting the bike in early morning ( when is it colder ). It is a bit of struggle to get it fired up, but it does fire up eventually even on colder mornings )

You are right, it may not be the 'choke' ( but a fast idle like you said )
My guess is something is binding mechanically as well ( as you said ).
( First will be removing the body panels on any sports bike, so a there is a bit of hesitation in me about that. )

[smsw]

Not much choice about removing the fairing.  You will have to get to the other end of the choke cable to figure out if the cable is binding, or something else.

[Kev m]

I have not checked anything yet. Throttle works normally.. and I actually drive the bike without any issues.
( Only issue is starting the bike in early morning ( when is it colder ). It is a bit of struggle to get it fired up, but it does fire up eventually even on colder mornings )

You are right, it may not be the 'choke' ( but a fast idle like you said )
My guess is something is binding mechanically as well ( as you said ).
( First will be removing the body panels on any sports bike, so a there is a bit of hesitation in me about that. )

I would want to fix it

But if it's truly just a fast idle lever, can you not just crack the throttle slightly on cold starts to compensate (until it is fixed)?

[MotoGuzzi750]

Mine came to me not working, froze up. Turned out to be the cable and no amount of lube or persuasion would budge it. Found a good used one on ebay.

Could you please describe a bit more how to replace the cable, since this is my first time on zx12r ?
Any ideas/tips would help.

I am thinking it would be very useful to know from someone who has actually worked on this, in a sort-of step by step process please ?

Thanks in advance !

[MotoGuzzi750]

Interesting bike - so it's a 4-throttle body EFI setup with a "choke" cable (I'm assuming that's a fast idle lever in reality that works on the synchronized throttle linkage?).

What have you checked so far?

Condition of lever, cable (including routing, look for kinks or damage), and where it attaches on the linkage.

The throttle is working normally opening and closing smoothly? If it is, and I'm right that it's a fast idle lever, then something must be binding mechanically on the lever/cable/linkage.

Question/thought:

Since it is fast-idle ( and not choke ), then it should have a role to play in starting on colder mornings, right? ( if I open up throttle a bit manually )
I am trying to asses how critical/urgent this issue ?
And if possible postpone the cable repair/replacement until I have some more bandwidth to do so.

Thanks!

[Kev m]

Question/thought:

Since it is fast-idle ( and not choke ), then it should have a role to play in starting on colder mornings, right? ( if I open up throttle a bit manually )
I am trying to asses how critical/urgent this issue ?
And if possible postpone the cable repair/replacement until I have some more bandwidth to do so.

Thanks!

Assuming no prior knowledge:

* A choke is used by carburetors to restrict airflow during cold starts. This restriction in effect makes the mixture richer to help with the cold start.

* An EFI motor controls air/fuel mixture based on sensors like air temperature, air pressure, engine temperature, and throttle position. As such it doesn't want/need air restriction during cold (or hot) starts. BUT since the idle system is normally physically set at a point of airflow for HOT idle, it can be insufficient air for cold starts.

EFI motors generally use various methods to deal with the greater need for cold idle air.

Many EFI system use an idle bypass/idle air control servo - this is an electronically controlled device that allows air past the throttle plates. Some EFI systems (usually fly-by-wire) don't use this device, but instead simply open the throttle more during cold starts and cold idle operation (since the ECU has direct control of the throttle plates).

A number of earlier/less sophisticated EFI systems used mechanical control - i.e. some form of fast idle lever to physically hold the throttle plates open during cold start/cold idle operation. It is why these motors will over-rev somewhat if the lever is left in that position once the motor is warm. It is literally no different than holding the throttle linkage open by hand. So in these cases, SHOULD the mechanical means of holding the throttle open fail (cable breaks in some way) then simply holding the throttle open slightly should accomplish the exact same thing.

[MotoGuzzi750]

Mine came to me not working, froze up. Turned out to be the cable and no amount of lube or persuasion would budge it. Found a good used one on ebay.

Most likely I will end up going this/your route.