Prairiehammer

I think you are on the right track with suspecting the diaphragms. 'Holey' diaphragms will still dance at idle, but when you want to go fast, the holes prevent sufficient vacuum to fully open up the slides and needles. Bite the bullet and remove the diaphragms and carefully inspect them. It is an easy-peasy task. There are two sources for new diaphragms that I am aware of. SCI (SIRIUS CONSOLIDATED INC) is a Canadian company that sells diaphragms for the Venture. JBM Industries is a another source. http://jbmindustries.com/

Evansville? That's south of the Mason-Dixon Line isn't it? I'm not sure if I am allowed to return to the 'South' after my last escapade there. Perhaps if I travel incognito, I can get past those Indiana troopers.

The shift sector (or as Yamaha calls a "segment") from the Second Gen Venture: 4NK-18185-00-00, is a direct replacement for the sheet metal captured First Gen shift segment.

Definitely!

Set the idle to a bit more than the recommended 1000 rpms. Will it idle now for more than twenty seconds? Are you using the 'choke'? Does increasing the choke help to keep it idling? Or does increasing the choke cause it to die? Do you have good spark on ALL cylinders after it dies? These engines will idle, albeit slowly on two cylinders. If you remove the outlet hose of the fuel pump you should see it spurt, but it is not a strong stream. The fuel pump is a reciprocating pump with a pressure of 2± psi. Also, the fuel pump will stop operating after 4-5 seconds if the engine is not firing. So simply checking for fuel pump output while the fuel pump is connected to the bike's wiring will result in pump cessation after 4-5 seconds. To check for continuous pump operation, the pump must be disconnected from the bike harness and 12 volts applied directly. And I ask again: do you HEAR the fuel pump operate when you turn on the ignition but before you start cranking?

If the red/white wire on the relay was severed, the engine would still crank but there would be no spark. ...(I think! )

At boats.net the proper part number is 36Y-81940-00-00, $67.68. Alternately, check on eBay for any 1986-1993 Venture 'starter relay'. In fact the same part is used on many other Yamaha models; FJ1100, Maxim, Virago, VMax, etc. Plug the part number into an eBay search and get 45 hits, starting at $11 for new.

IF carb removal is required, the main fairings (and everything within) can remain. Remove the lower fairings (the "L" shaped cowlings in front of the rider's shins), the side covers and the aforementioned air box. The main fairings may remain in place. The four carbs are removed as a single unit through the left side. But, to be frank, unless the 'technician' royally screwed up, you should be able to fix the leaking float valve without carburetor removal. It IS possible, though that he screwed up the carbs during reassembly or carelessly bent the float tab or failed to renew the valve seat O-ring or failed to replace the float valve needle or it could be something as simple as debris is caught under the float valve. This debris can come from the handling of the thirty year old fuel inlet hose, causing bits to slough off from within the hose. There is a "net filter" ( a fine metal mesh screen) at the inlet to each float valve that should have caught the largest pieces of debris, but it wouldn't take a large piece of debris to wedge the float valve open.

Really!? That would be a very old poster! The 1st Infantry Division is the oldest continuously serving division in the United States Army. It has seen continuous service since its organization in 1917. Do you have a picture of that poster? I'd like to see what it looks like.

Brenner, I know the horse is out of the barn now, but I thought you might find it interesting that apparently many others have suffered with lost saddlebags to the extent Yamaha actually felt the need to publish a Tech Bulletin. From 1983: XVZ12 Saddlebag Alert.pdf

Some side stand relay may have a blue base with a blue connector. It is labeled as "OMRON 4U8-01, or similar. Wire colors: Blue/white, Red/white, Black/white, Black.

No, there will be no access to the float chamber until you disassemble the carb. However, before you send the bike back to the shop that did the work, try tapping on the float bowl of the offending carb(s) with a plastic screwdriver handle or large wooden dowel, with the hopes that this action will jar the sticking float needle valve or hung up float. If you are encountering fuel "spraying" from the vacuum dampener, you have a LOT of fuel being dumped into the intake of that cylinder. The risk of hydro lock is high, not to speak of the damage done as the cylinder wall is washed of its lubricating oil. Keep an eye on your crankcase oil level; the gasoline is likely accumulating in the crankcase and raising the oil level.

When looking down onto the top of the carbs, with the air cleaner element removed, you are not observing the 'floats' move, but you are (hopefully) seeing the carb slides move. The carb floats are not visible until the carb is disassembled. The floats control the fuel level within the carb float bowls. While it is highly likely that the carbs may require cleaning, it is not likely that your problem is dirty jets. If the engine will idle satisfactorily at the recommended rpm (950-1050) for 'twenty seconds' and then die, and you cannot restart the engine immediately, that indicates a fuel delivery problem or an ignition system problem. After idling for twenty seconds at the recommended idle rpm, does it quit suddenly or does it begin to idle slower and slower with an accompanying dropping of one or two cylinders? If so, it would appear to be fuel related. If, on the other hand, after 'twenty seconds of proper idle it suddenly quits, it may indicate an ignition issue. When it quits idling, is there spark? When it quits idling, is there still sufficient fuel in the carb bowls? After it quits idling, and when you cycle the iginition key on and off and back to ON, do you hear the fuel pump clicking as it attempts to maintain the fuel level in the bowls. For that matter, do you ever hear the fuel pump clicking, especially when turning the ignition key on after an extended shut down? To remove the carbs, the main upper fairing does not have to be removed. The lower fairing parts will have to be removed, as well as the side covers and of course, the false tank cover.

Wow! I didn't know my identical 1983 Standard was also "Custom Made".

He states that the plastic was badly repaired, so he used decals and stickers to hold it together.

Thank you, Pat for the additional information.

That plastic device is a dampener for the vacuum source for the boost sensor (vacuum advance). There should be no fuel in that hose. Perhaps, the fuel you see is actually coming out of one of the carb bowl drain hoses and running onto that vacuum hose? Surely, the person who redid your carbs didn't mistakenly hook up that hose to one of the bowl drain hoses? The bowl drain hoses should only have fuel coming out of them when the carb bowl drain valve is open or leaking.

For the '83, either a Crescent wrench or screwdriver are needed to change from OFF to ON (there is no RESERVE on most 1983), but be warned (!) that the plastic valve is sometimes difficult to change positions without breaking the exposed part of the petcock. If the slot in the petcock is vertical it is ON. (See accompanying pic). On the 1984, there is an arrow to designate position. Broadly, if the knob is horizontal it is OFF. In the vertical position it is either ON or RES, depending on the arrow (See accompanying pic.)

SOME, early 1983 exhibited breakage of the frame near the rear shock relay arm connection and the center stand mount. Is that what you are asking about?

Attached are my scans from the various manuals I own. It appears that the MKI have a more frequent valve inspection/adjustment. Perhaps, Yamaha decided after three years that the frequent valve inspections were unneeded?

There is a difference in fuel petcocks and fuel pump circuitry between 1983 (as your post title indicates) and 1984 (as your profile indicates). What is the full VIN of your bike? Look on the lower frame rail beneath the brake pedal. The 1983 fuel petcock is tool operated and hidden behind the right side cover. The 1984 petcock has a hand operable knob and is visible with the side cover on. The 1984 fuel pump circuitry has two relays, the fuel pump relay and the fuel pump control unit.

Usually, when the resume light is lit but one is unable to set the cruise it is due to either clutch lever switch, brake lever switch, rear brake pedal switch or wiring to and from these switches. Insure that the plunger within the lever switches (especially the clutch lever switch) is free and extending fully when the levers are at rest. Disassemble and clean the lever switches. Make sure there are no open or shorted wires on these switches.

All Yamaha 1983-1993 XVZs and Yamaha FJ, VMX take 25mm shims, as do many Hondas and some Triumphs, so don't get fixated on finding shims JUST intended for the Venture.

Thank you, Kim for your contribution to the database. Yes, it helps. Yours is one of the oldest in my database still on the road.

PayPal sent for two silver. Thanks.