It acted like it was running out of fuel ?

[Ponderosa]

1984 Venture Royale: I've owned it a few weeks, been riding it to work everything has seemed to be working well. Filled with fuel and came home and parked the bike. My wife got home a little less than an hour later and suggested we take the bike and go out to dinner, "great idea Honey". I get the bike out of the shed, clean the bugs off the windshield, fire it up and we head out the driveway. Everything was functioning nomally up to this point. As we headed up the driveway, the engine stumbled a little, then caught, then stumbled again, acting like it wasn't getting fuel, thumbed the choke for a second, she caught, then stumbled and quit. Tried to restart,she would fire and run a few seconds but wouldn't take much throttle, and quit again. Same thing three or four times. I thought hmmmm clogged fuel filter? malfunctioning pump? restriction in fuel line? plugged tank outlet? Pushed home and parked in the driveway and took the pickup . Next morning tried to start it, same thing, run a few seconds and quit. Didn't havetime to tear into it so left it sit for a couple of days. Came back disconnected fuel output line from filter, flow was good.... disconnected fuel line from carbs and cycled ignition, flow and pressure were good?????hmmmmm. Hooked everything back up and she fires up and runs fine.... ??????? Am a bit nerveous to get the horse too far from the barn. Any thoughts?

[Yammer Dan]

Sticking floats?? Sea-Foam it?

[Monty]

Drain the carb bowls and fill 'em with Sea-Foam.

[GeorgeS]

Next day, drain the bowls again:

 

After you get it running, put about 1/2 can of Sea Foam, per tank, and Run it " Hard " for a couple of tanks of fuel.

 

A new set of plugs might be in order, also.

 

If all this does not do the trick, then start cleaning electrical plugs, Start with the TCI, and the Plug in the cable going from the TCI down to the " Ignition Pick UP Coiles "

 

Next thing, would be to start looking for " Intake Air Leaks" above and below the Carbs, also check the Intake Manifold bolts, where mounte to the heads.

[jasonm.]

LISTEN UP....IT'S the DAMN safety switch on the kick stand!!!! Happened to me 20 years ago and by-passed it since. Never happened again. Always try the simplest thing 1st. There a 3 wires coming up the left side frame by your leg from the stand, blue/yel, green and black. You need to cross the blue/yell to black. DO NOT cut thru the wires. Just make a jumper.If you cannot solder a jumper, A scotch lock can work . This will preserve the side stand warning light but not kill the engine.

Edited June 29, 2010 by jasonm.

[dingy]

LISTEN UP....IT'S the DAMN safety switch on the kick stand!!!! Happened to me 20 years ago and by-passed it since. Never happened again. Always try the simplest thing 1st. There a 3 wires coming up the left side frame by your leg from the stand, blue/yel, green and black. You need to cross the blue/yell to black. DO NOT cut thru the wires. Just make a jumper.If you cannot solder a jumper, A scotch lock can work . This will preserve the side stand warning light but not kill the engine.

 

 

Side stand switch is absolutely, positively, NOT the problem with these symptoms.

 

Gary

[Ponderosa]

Since my initial post I decided to chance it and took the bike out for a ride (had to run into town to pick up some Sea Foam anyway). Rode to a job site, then to town, made several stops there, then returned home... about 70 miles. No reccurence of symptoms, the bike ran normally. It's hard to diagnose it and fix it if it won't stay broke.

As soon as I get a little time (perhaps towards the weekend) I will do the Sea Foam treatment as suggested, as I too consider sticking floats to be a possibility.

I will probably be looking a little deeper into the intake system in the not too distant future as the PO mentioned that he had disassembled and cleaned the carbs. A comment like that always gets my attention, as I don't think most people have any business inside of carburetors.

When I had the air box off I noticed a few things that are goning to need a little attention, some sooner than others. PO had duct taped off the spiggot on the bottom of the air box where the crankcase vent is supposes connect and I couldn't spot the hose from the crankcase vent..... will have to track that down and make sure proper crankcase breathing and filtration is happening (real soon). Also noticed that with the engine running and blipping the throttle that the slide on number four is pretty lazy and doesn't like to come to the party until you nail it pretty hard and the tach gets into the 5G territory....... probably looking and diaphrams and syncing the carbs (can wait a little bit)

Also a question....On all of the other "vintage" Yamahas that I have worked on, the float bowl overflows were connected to tubing that routed any potential overflow to a supposedly preferable location. There doesn't appear to be any tubing present that would perform that function. Should there be?

[jasonm.]

the overflow consist sof a simple pipe on the bowl. NO internal tube. And it only works when the bowl is totally full. The fuel dumps on top of the rear shock. This design is problematic, as it can allow for a very high float level and you will never know it.

[frankd]

I really don't think it's a carb problem. The odds of all 4 developing a problem and then dis-appearing at the same time is pretty remote. However, any chance you picked up some water in your fuel?? Have you (or maybe the previous owner) ridden in a downpour?? My 83 had a problem with sucking water up the fuel tank vent hose. The water that goes in the tank collects at the bottom of the tank. Then the fuel filter gets about half full and the water gets pumped into the carb bowls. When the water in the bowls gets drawn into the jets, the motor can act like it's going to quit. When you open the throttle and wind it up, it sucks more of the water in the main jet and it quits gaining speed.

 

Or maybe you have a fuel pump problem. Could you hear the fuel pump running when you turned the key on??

 

Frank D.