Choke not doing a whole lot...

Firstly, thanks to all of the buying advice I received earlier this month. It proved helpful and I am now the proud owner of a shiny red 94 VFR750.

The only hiccup so far is that the choke doesn't seem to raise the idle much (maybe 100-200rpm) when cold and it sputters a tad. Raising the idle speed helps, but I know that is counter-productive.

Is this a common issue/fix?

The owner did mention that the bike is due for carb balancing since he installed a DynoJet Stage1 kit (I know that could be a can of worms).

I just want to get my bearings (and the service manual) before I start pulling things apart.

Thanks in advance & cheers!
Patrick

 

Take out some slack in the choke (actually "Enrichener Circuit", to be anal...) cable.

There's a barrel-adjuster where the cable connects to the linkage - just follow the cable down from the little lever until you find it.

Also make sure it is getting full travel - loosen the cable until very slack and manipulate the little pushrod with your fingers or with pliers (gently) a few times so it moves freely.
A shot of WD-40 into the pushrod will help if it seems gunked-up.

Lubing the cable would also be a good idea.
Disconnect the cable at the lever - use a cable-luber tool with chain lube, or carefully drip a bit of motor oil down into the end of the cable while holding it vertically.

 

Does your bike need the choke to start ??
on installing the jet kit the mixture screws may have been adjusted richer, so if your idling bike runs OK, then adding any choke would over-enrich fuel mixture and not increase idle speed.
it's not uncommon for carb-modified bikes to need little-to-no choke for starting A half-turn in on the idle adjustment screw for start/warm up will have it running best.

 

Thanks for the info guys... It's getting a little cold here, so it's a little tough to troubleshoot.

I play around with the choke cable and see if its not getting full travel.

Yeah, without choke it barely idles. I've got a Morgan Carbtune on the way, but I think that will have to wait till spring. Winterizing is scheduled for tomorrow. out:

Cheers,
Patrick

 

first you need to find and check the setting on your "Idle speed adjusting screw".

if it won't idle without choke then your carbs may need cleaning because of plugged jets.......try running Sea Foam through the fuel system or use Yamaha brand carb and fuel system cleaner.
did your bike sit unused for some time, the most common cause of plugged jets??

 

I just got my bike back from the dealer after they did some work on it. I now have a very similar problem. I just assumed it is running a little rich so therefore does not need a lot of enrichment to get it started. But now I'm thinking maybe I just need to check the cables and idle speed to make sure everything is fine.

Assuming all that stuff checks out I'll try some seafoam. I hear it works wonders. Hopefully I won't have to go back to the shop again.

-J