1983 venture starts w/choke wont idle past 20 secs.

[kinsmd69]

Hi everyone. I became a venture owner a couple weeks ago. Im currently working on trying to get it to stay running.

It sat for awhile, but prev. owner new procs. to empty tank and carbs for winter storing. I can start the bike w/choke on

but only idles for 20 secs.

 

1. Where is on/off fuel shutoff. ? I've read its suppose to be by right foot peg, but still can see one. Was it option

on the deluxe model? Or hidden by chrome piece? Ive had a bike for over 30 years , but still only a shadetree mechanic.

If choke is all way on, and throttle turned 2 mm, bike starts and idles weak for 20 secs. Any suggestions???

 

2. Fuel filter is ok. Trying to find jets behind brass covers, which I have loosened.

3. Is there a easy way to test fuel pump.? Ive started it 8 times, so figured gas valve should be on or

on reserve, and fuel pump ok? ?

4. Its there an easy way to put on C clip on shifter rod?

[Prairiehammer]

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.

[kinsmd69]

Prairiehammer, thanks for the response. I actually have both. Bought a 84 project, then came across a 83. Found both fuel petcocks. what tool do u use for the 83? Would channel locks be ok, or 3/8 wrencth? The line in the petcock is in vertical pos. Is that off, on, or reserve? The 84 is in a horizontal position, which one is that? Are the two years the same? Thanks again!

I feel like an idoit. Ive had bikes for 40 years, only light shadetree work, but still didn't see them. ugh!

[Prairiehammer]

Prairiehammer, thanks for the response. I actually have both. Bought a 84 project, then came across a 83. Found both fuel petcocks. what tool do u use for the 83? Would channel locks be ok, or 3/8 wrencth? The line in the petcock is in vertical pos. Is that off, on, or reserve? The 84 is in a horizontal position, which one is that? Are the two years the same? Thanks again!

I feel like an idoit. Ive had bikes for 40 years, only light shadetree work, but still didn't see them. ugh!

 

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.)

[kinsmd69]

Thanks again. Unfortunately, that wasn't my problem. When the bike does idle for 20 secs. , w/air breather out, I can see the floats moving freely. Should I try and up the idle and set the balance

between the carbs, or bite the bullet, and take carbs off and clean the jets? Also, to take off the carbs, does the fairing have to be removed or separated?

[Prairiehammer]

When the bike does idle for 20 secs. , w/air breather out, I can see the floats moving freely.

 

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.

 

... or bite the bullet, and take carbs off and clean the jets?

 

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?

 

Also, to take off the carbs, does the fairing have to be removed or separated?

 

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.

[kinsmd69]

Thanks for the correction, slides. The bike will turnover again and idle slow again, for another short time. When give a little throttle, it just dies.

It slowly decreases in idle, and then dies. I have good spark. Will taking the "out line' off fuel pump tell me anything of fuel pressure, low or high?

[Prairiehammer]

The bike will turnover again and idle slow again, for another short time. When give a little throttle, it just dies.

It slowly decreases in idle, and then dies. I have good spark. Will taking the "out line' off fuel pump tell me anything of fuel pressure, low or high?

 

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?

[kinsmd69]

Yes, fuel pump clicks each time the key is turned on. Always. Bike will only start with choke on all the way! If not on all the way, it wont start. Also, it seems

that only the rear cylinders are getting warm when idling. Will check spark next on front cylinders.

[kinsmd69]

I have spark on all 4 cylinders. Fuel pump clicks on each time with turn of key. Will try switching out another fuel pump

tomorrow , to see if first one is weak.

[Vonwolf]

When you're starting it do you have the air filter in and the air box lid on, these bikes don't run at all without it. It took me a long time to figure that out

[kinsmd69]

No, Vonwolf. Actually, I had the air breather in, but lid off, and it would start and idle poor for 15 secs. Now, that I put

the lid on the air breather box, it wont even start with choke on full and idle. Now, there is just small backfire(puff)(?) thru carbs

sound. Will try swapping out fuel pump tomorrow afternoon.

[kinsmd69]

Ok, apparently, the fuel pump isn't clicking on everytime with the key. Is there something, fuse?, to check to see

why the fuel pump stops clicking after the second or third time to start bike?

[Prairiehammer]

Ok, apparently, the fuel pump isn't clicking on everytime with the key. Is there something, fuse?, to check to see

why the fuel pump stops clicking after the second or third time to start bike?

 

The fuel pump is an "on demand" pump. If the float bowls are full, the pump will not run, until there is a demand for fuel (fuel being consumed from carb float bowl).

[kinsmd69]

The fuel pump is an "on demand" pump. If the float bowls are full, the pump will not run, until there is a demand for fuel (fuel being consumed from carb float bowl).

 

 

Ok, I read about checking float bowls with clear tube. Can someone show a pic of flow bowl on the carb? Is it behind the brass fitting with the jet?

 

If float bowls are receiving enough gas, but bike wont start, like starving from fuel, and have spark, what's next?

 

My bike only has 7500 miles on it. The PO always ran the gas out of it, followed a check list, for the winter.

[Prairiehammer]

Can someone show a pic of flow bowl on the carb? Is it behind the brass fitting with the jet?

 

Here a couple pics that show where the float bowl drain lines are as well as the float bowl drain valve. Also a pic that shows the fuel level gage mark on the side of the carb body.

Attach a clear hose to the drain line, open the float bowl drain valve and observe the fuel level in the clear tube. The fuel level should be 14mm ± 0.5mm (according to the 1983 Yamaha Service Manual) below the mark on the carb body.

 

[kinsmd69]

Here a couple pics that show where the float bowl drain lines are as well as the float bowl drain valve. Also a pic that shows the fuel level gage mark on the side of the carb body.

Attach a clear hose to the drain line, open the float bowl drain valve and observe the fuel level in the clear tube. The fuel level should be 14mm ± 0.5mm (according to the 1983 Yamaha Service Manual) below the mark on the carb body.

 

[ATTACH=CONFIG]98970[/ATTACH]

[ATTACH=CONFIG]98971[/ATTACH]

 

Thanks for the pics. So, is the idle screw the one between the float drain lines with the big head?

[Prairiehammer]

Thanks for the pics. So, is the idle screw the one between the float drain lines with the big head?

 

Yes.

[van avery]

If you can find the right size clear tube you can insert the drain hose into it ( with tight fit) and check the fuel levels.

[kinsmd69]

Ok, drained all the bowls. Left front(1) had about 18ml, smelled old, left rear(2) had 18ml and smelled like new gas.

Right front(3) had 18ml and smelled old, right rear (4) was empty!! Is there a separate input line I should check on

number for 4 carb? If I turn key to fill up bowls, and empty them a couple times, is this good to clean out the carbs?

 

Idle mixture screws have black rubber sealant on them; is that factory or have they been adjusted before? 7500 orig. miles on bike.

[syscrusher]

If I turn key to fill up bowls, and empty them a couple times, is this good to clean out the carbs?

 

 

Drain the bowls, leaving the drain valves open, then attach your clear plastic line 6" or so on the drain lines and then attach a funnel of some kind to that (syringe without plunger, turkey baster...). Pour Sea Foam into the plastic line until it will take no more. This should be filling the float bowl with Sea Foam, if you are holding the top of the plastic line well above the carb. Close the drain valve with the line held high and repeat this with each carb. DO NOT turn on key again. Leave this for from several hours to overnight. When it's time, go ahead and drain each bowl again, closing each drain valve as you go. This should have cleaned or at least loosened deposits around the float valves and bottom of main jet, etc. Let us know how it runs after you complete this step.

[kinsmd69]

OK! Put sea foam in drain hoses, drained out of bowls 4 hours later. Replaced 3 spark plugs, 4th - right front giving trouble, its tight and socket slips, might let shop do that one.

Turned key, fuel pump clicked up, choke on high, started right up! After 60 secs. running, smoke started at right rear cylinder(4th) by exhaust connection from cyl. head to exhaust.

Cant tell anything on it. But its at where the small bolt is on the exhaust side, 2-3 inches down facing out.

Also, any hints on putting c clip back on shifter rod lever? Pics coming tonight!!!!

[kinsmd69]

Oh, and all cylinders getting warm. Will re -start on choke immediately, 20 secs take off choke, and idles at 700 rpms. Sounds smooth and no missing.

Still have to get clip on shift lever

Find smoke problem. Don't wont to over heat right rear cylinder. Have started 3 times and let run for a minute, until smoke starts, then shut off and cool again.

Top two lights on left, on control panel, are on. Looking them up now. Thanks all!!!!

[Prairiehammer]

OK! Put sea foam in drain hoses, drained out of bowls 4 hours later. Replaced 3 spark plugs, 4th - right front giving trouble, its tight and socket slips, might let shop do that one.

Turned key, fuel pump clicked up, choke on high, started right up! After 60 secs. running, smoke started at right rear cylinder(4th) by exhaust connection from cyl. head to exhaust.

Cant tell anything on it. But its at where the small bolt is on the exhaust side, 2-3 inches down facing out.

Also, any hints on putting c clip back on shifter rod lever? Pics coming tonight!!!!

 

That 'bolt' is a plug. A technician would remove that plug and screw in the CO sensor of the exhaust analyzer.

To avoid confusion: the cylinders are numbered thus: LF=#2, LR=#1, RF=#4, RR=#3.

[kinsmd69]

Ok, now I know what cylinders Im dealing with. Thankyou.

I have no vacuum gauges. Bike idles, but can tell this is missing, so guess carbs need synched.

Anyway to get the balance between the carbs close by ear?

 

Thankyou!