carbs again

After finding the missing vacuum plug, the idle on the '86 700 is steady now, no more fiddling with the idle ajust screw. But it's still a BEAR to get started. No bike should be this cold-natured.

The choke cable is adjusted correctly and does pull the choke plungers all the way out on the carbs.

Every other carbureted bike I've ever had, once the bike starts it isn't long, maybe 10 second or less, until the rev's are racing and the choke lever has to be moved back a little bit to modulate the idle speed, further and further, until the choke is no longer needed, maybe 5 minutes in all. I understand this "choke" is actually an enrichener, allowing more air into the fuel/air ratio.

This bike, when I pull the choke lever out all the way, it still turns over easily but will barely start and only idles at maybe 700-800 rpms, no higher. Then it soon cuts off and you have to take the choke off completely to get it to run, but it is still running too slowly and should have some choke. But it won't take the choke. Then after maybe 5 minutes it's fine for the rest of the day, idles great, no flat spots or hesitation or anything. If you try to give it choke once it warms up, it stutters and cuts out just like every bike I've ever had.

Note that it acceps fuel from the throttle readily, and I can at any time cold-start the bike by giving it a little gas at the throttle grip while it warms up. But I'm not supposed to have to do that.

When I cleaned the carbs, I was very careful with the idle circuit, having danced that dance before. I did not seperate the carbs from the rack, nor did I remove any choke parts, just the jets and float needle.
I wonder if the choke is right on these carbs, or can it be dirty still?

Like I said before, nobody would mistake me for a mechanic so I am ready to hear that I need to pull the carbs again. I cannot find any vacuum leaks (WD-40 all over the place under there, the idle never changed). Any experience much appreciated.....

[image: View Post]coffeebrake, on 26 October 2010 - 10:08 AM, said:

After finding the missing vacuum plug, the idle on the '86 700 is steady now, no more fiddling with the idle ajust screw. But it's still a BEAR to get started. No bike should be this cold-natured.

The choke cable is adjusted correctly and does pull the choke plungers all the way out on the carbs.

Every other carbureted bike I've ever had, once the bike starts it isn't long, maybe 10 second or less, until the rev's are racing and the choke lever has to be moved back a little bit to modulate the idle speed, further and further, until the choke is no longer needed, maybe 5 minutes in all. I understand this "choke" is actually an enrichener, allowing more air into the fuel/air ratio.

This bike, when I pull the choke lever out all the way, it still turns over easily but will barely start and only idles at maybe 700-800 rpms, no higher. Then it soon cuts off and you have to take the choke off completely to get it to run, but it is still running too slowly and should have some choke. But it won't take the choke. Then after maybe 5 minutes it's fine for the rest of the day, idles great, no flat spots or hesitation or anything. If you try to give it choke once it warms up, it stutters and cuts out just like every bike I've ever had.

Note that it acceps fuel from the throttle readily, and I can at any time cold-start the bike by giving it a little gas at the throttle grip while it warms up. But I'm not supposed to have to do that.

When I cleaned the carbs, I was very careful with the idle circuit, having danced that dance before. I did not seperate the carbs from the rack, nor did I remove any choke parts, just the jets and float needle.
I wonder if the choke is right on these carbs, or can it be dirty still?

Like I said before, nobody would mistake me for a mechanic so I am ready to hear that I need to pull the carbs again. I cannot find any vacuum leaks (WD-40 all over the place under there, the idle never changed). Any experience much appreciated.....



Besides the idle circuit there is the enrichment circuit. I missed it more than once, resulting in pulling carbs again. Maybe you cleaned it, but maybe not. If I remember right, it is the narrow part of the carb body that extends into the float bowl. This also has a very small hole like the idle circuit jet. But this jet/oroifice cannot be removed. I used a strand of copper wire to unplg on all 4 carbs and that solved my 'choke' starting problems.

Thanks, is this enrichment circuit what comes into play when the choke lever is pulled?

I remember putting fluid through it. But I'm sure there could be more gunk in there by now, I know sometimes it takes a few times.

With these symptoms, could it be anything else?
When I got the bike it would only run on full choke, now it runs great when warm but seems that the choke isn't doing any good for cold starts. Hence my reasoning that it's the choke circuit. Anybody care to say if that's it or not?

[image: View Post]coffeebrake, on 26 October 2010 - 03:16 PM, said:

Thanks, is this enrichment circuit what comes into play when the choke lever is pulled?

I remember putting fluid through it. But I'm sure there could be more gunk in there by now, I know sometimes it takes a few times.

With these symptoms, could it be anything else?
When I got the bike it would only run on full choke, now it runs great when warm but seems that the choke isn't doing any good for cold starts. Hence my reasoning that it's the choke circuit. Anybody care to say if that's it or not?


Thanks, is this enrichment circuit what comes into play when the choke lever is pulled? - Yes
Now it runs great when warm but seems that the choke isn't doing any good for cold starts. Hence my reasoning that it's the choke circuit - Thats the same symptom I had.
On idle (don't rev it) make sure all pipes heat up too, might point you to the faulty carb.

Very cool, thanks.

I know the carbs are a little bit of a pain to get back on, but compared to my inline fours with the air box behind, the VFR is positively easy to work on....