Bike not catching on start

[chukzelda]

Hi,

 

Find attached an mp3 audio file of me starting my bike. It's hard to describe but the bike will start, then die. I've put in a new sealed battery, changed the spark plugs and rode 40 miles yesterday with 1/4 can of seafoam in the tank.

 

What do I need to look at next?

 

Thanks

chuk

[chukzelda]

Sorry, 85 Venture Royale.

 

Chuk

[mbrood]

First, I would Ohm from the sparkplug cap to the ignition fuse, looking for right around 23k Ohm... 10 for the cap and 13 for the coil... any more and you have corrosion to clean between the cap and coil.

 

Then, pull the plugs and see what's happening... are they dry, fuel soaked, sooty...

[chukzelda]

Find attached a photo of the old 4 spark plugs I changed out yesterday. Do they tell you anything?

 

I'm new to multimeters. I watched a video on how to check for resistance. Is the procedure;

 

1. Put negative multimeter tip to negative terminal of battery

2. Put positive multimeter tip to spark plug wire cap

3. Read resistance (should be under 23)

 

Thanks Chuk

[mbrood]

The top and middle plug look good but it's hard to tell... you really want to look at the electrode and the white insulator around it... ideal is a medium tan. White and flakey means you are way too lean and that leads to detonating an engine... if that's the case it needs resolved before any futher use.

 

The other too look a bit sooty... a bit too rich, probably. The one on the left looks almost fine... not too black.

 

But you want to try and start the bike... let it run (if it will) for a bit and then shut down and pull the plugs... even wet plugs will dry out if left for awhile.

 

resistance checks don't care about polarity of the leads... there is no polarity.

 

but the resistance check is between the plug holder and the ignition fuse...

[chukzelda]

Mbrood,

 

Found my fuse box (top of battery) popped it open and see 5 fuse holders, but 4 fuses. The 1st fuse holder is empty and if you notice, the wiring has been cut to it.

 

I've looked in my 2 manuals but can't find a fuse diagram. Can you tell me which is the ignition fuse and what the empty 1st fuse is for?

 

thanks

Chuk

[dingy]

Mbrood,

 

Found my fuse box (top of battery) popped it open and see 5 fuse holders, but 4 fuses. The 1st fuse holder is empty and if you notice, the wiring has been cut to it.

 

I've looked in my 2 manuals but can't find a fuse diagram. Can you tell me which is the ignition fuse and what the empty 1st fuse is for?

 

thanks

Chuk

 

 

Top spot is for the ACCY fuse, 2nd is headlight 10A, 3rd is Ignition 15A, 4th is Signal 15A, 5th is Tail 10A.

 

Wiring diagrams are located at link below.

 

http://www.venturerider.org/forum/showthread.php?t=42358

 

Gary

[dingy]

Listened to your sound clip.

 

First guess is idling to low.

 

Carbs need sync'ed.

 

Idle mixture screws may need adjusted.

 

Carbs may need tore down and cleaned, there are 4 jets in each carb and one is very tiny, happens to be the idle one.

 

Gary

[mbrood]

It would help to mark them... When trouble hits out on the road, it's real handy to know what you are touching.

[chukzelda]

Thanks for the Fuse information Dingy. Putting 1 tip of the multimeter on top of the metal end of fuse 3 and another tip touching the metal cap inside the spark plug cable, I get a reading of about 16 for each one (I tested all 4). Is this good?

 

I started and ran the bike for 2 minutes. Attached is a closeup of one of the plugs.

 

Chuk

[mbrood]

The coil should read 13k Ohms to the ignition fuse +/- 1K... I will have to assume you are using a different plug holder that has no 10k resistor... ?

 

That plug look like it's been TOO hot... I would open the idle mixture screw about a 1/4 turn. But FIRST I would gently turn it IN (CW) until it gently seats, counting the turns it took, including 1/8th turns... then back it out the same number plus that extra 1/4... I would also write this down for a status of where you are currently at that adjustment.

[chukzelda]

Mbrood,

 

I've read through the posting in the 1st gen library on how to synchronize the carbs. Looks like I'll have to order up a carbtune or find one at the auto parts store.

 

I've also been pouring over the PDF manual and am having a heck of a time finding the idle mixture screw. Can someone point me at a good picture of it or snap a shot and post it? I've pulled over the side panels and put a light in there but can't figure it out. Either I'm getting old or it's well hidden :}

 

thanks

Chuk

[bkuhr]

idle screw likely under brass plug needs pulled out. (drill small hole, then screw in sheetmetal screw, then pull on screw with pliers to remove plug)

[frankd]

When I listened to your audio clip, it sounded like you didn't have enough choke on. Did you use the choke?? How much?? Are you sure the choke cable is connected and adjusted correctly? If so, I agree, turn the idle speed screw (the knob under the back of the left front carb) clockwise about 1/8-1/6 of a turn. Another thought....you do have the airbox cover on and a filter installed don't you?

 

Did you buy the bike in this condition or did this just happen??

 

Frank D.

[chukzelda]

Hey guys,

 

It's been suggested to me that I replace the fuel filter before I start fiddling with the carbs. I read the postings on how to do this, pulled the fuel filter, ran to the auto store for a match, installed the new filter and it looks good so far.

 

To recap, in the past 2 days I've;

 

installed new sealed battery

changed spark plugs

installed new fuel filter

 

Up to this point the choke has had a negative effect on starting the bike. Today with the choke on full, bike fired up and was running at a high RPM. I quickly pulled the choke back a bit so bike was idling around 1k on the tach. However, after letting it run for a few minutes, I pulled the choke to off and the bike was idling around 400 on the tach.

 

If the tach is accurate, I'm idling too low, right?

 

If I understand the advice, what I need to do now is adjust the idle on each carb (4 of them) to get the idle up to 1k??? I've never adjusted the idle on a 4 carb bike, what's the procedure for doing this?

 

Attached is a photo of one of my carbs. Is the idle adjustment screw the red arrow (and the idle screw is in the deep slot) or is it the green arrow (and I have to remove that silver plate thingie)?

 

I'm working the program guys :}

[mbrood]

The photo below is of the carbs upside down... with the left carb bank on the left. To the hard left, hooked to the gold bracket holding the drain tubes, in the middle is the large silver knob. THAT is the idle adjust. The single slotted screw there adjusts the sync balance between the #1 an #2 carb... while the 2 on the right bank adjust the balance for #3 and #4 and the other balances the left and right bank. The slotted screws should really only be tinkered with using a sync tool.

 

http://www.bergall.org/temp/venture/carb3.jpg

[chukzelda]

Ok,

 

I think we finally have this thing licked. After much searching by touch, I found the idle adjust screw. I don't know if it's my bike or what, but there are a number of hoses that completely hide this screw. By reaching both hands under and up, I was able to turn the screw a partial turn and the idle went up smoothly.

 

Went for a ride and the bike has more pep and sounds a lot better. Idling at 1100 at the moment and the bike starts each time without any need for the choke.

 

A big thanks to everyone who helped me through this. At some point I'll get my hands on a carb synch tool and tackle that job, but for right now I'm a happy venture rider.

 

peace,

Chuk