Engine stops when choke valve is half way pushed in

[Ucan]

Hi All,

I was out of country the last 4 months so could not ride my Yamaha VStar 650 for a long time. It has only 300 miles on it by the way. Yesterday I fired it and found out that the engine rpm is low at full choke. It used to sound really loud with high rpm at full choke, now it's relatively quiet and seems lower rpm. I warmed it up anyways and rode it for a couple of miles. The engine stopped couple of times while I was riding.

Today I started it again and left it warm up for 30mins with full choke. Again the same problem. When I push choke valve in (almost 1/2 of the way), engine stops - even if the engine is totall warmed up.

What do you think?

Thanks so much.

Ucan

[CORSCO]

Sounds like a carb clean is in store for you if it sat 4 months. Try draining the carbs and fuel tank and put some fresh plugs in her, you may get lucky. Otherwise, the carbs will need to be soaked. Good luck.

[Social Distortion]

also try some of that SEAFOAM stuff.
Dump some in your gas tank, swish er around a little and see if they helps clean them up a tad

[qwerty]

Did you change the oil before you left?
Did you change the oil before you rode?

If not, change the oil before cranking the engine again. Either way, running for 30 minutes with the choke full on probably gave your cylinder walls a good wash and maybe just voided your warranty. In the future, change your oil and filter before and after 90 days or more of no use. Do not run the engine after the pre-storage oil change or before the post-storage oil change.

Did you add a fuel stabilizer before you left?
Did you drain and refill the carbs and tank before you rode?

If not, you've varnished up your jets. You have two choices. First choice is take it to the dealer and fork over the big bucks for a carb or FI rebuild. That will work for sure.

Your second choice is to try a fuel additive if the problem isn't too bad. Since it runs, it probably isn't too bad. Here's what I do when resurrecting a neglected bike:

Change the oil and filter.
Clean or replace air filter as necessary.
Spray a little DeepCreep into each cable and work the cable well to work the oil in.
Grease all friction points.
Air the tires.
Lube the chain.
Charge the battery.
Check brake fluid and coolant (if applicable).
Check all control adjustments.
Check lights and horn.

Now I'm ready to start on the fuel system:
Drain the tank and carb(s).
Clean the fuel filter. The amount of varnish on the filter gives a pretty good indication of the level of varnishing of the carb.
Dump a can of SeaFoam Motor Treatment in a 1 gallon fuel can.
Fill the can with gas.
Dump the mixture in the fuel tank.
Turn the fuel on a minute to fill the carb(s), then turn it off.
Drain the carb(s).
Turn the fuel to reserve and fill the bowls.
Turn the fuel to on.
Move the bike to VERY well-ventilated area.
Start bike and hold at high idle (2500rpm or so, if you can see the tach through all the smoke that comes from burning SeaFoam) for about 10 minutes.
Drain the carb(s) and clean the fuel filter.
Fuel up with fresh gas (don't drain the SeaFoam/gas mixture already in the tank).

This done, you should notice a definate improvement in the way the bike runs. If it isn't quite right, just keep adding 2 ounces of SeaFoam per gallon of gas when you fill her up. Over time, the varnish in the carbs will disappear. Once the bike is feeling healthy, continue to run 0.75 ounce of SeaFoam per gallon. SeaFoam acts to keep moisture out of the fuel and also prevents fuel varnishing in storage--you'll never have the problem again.