problems with the throttle, vmax 92

[lsflp]

Good evening friends, I have a little problem with my old vmax, my bike when it reaches a high temperature, and without reaching the red line, it gets stuck the throttle I mean that the bike accelerates itself and is accelerated.
What can I check to correct?,
Thank you very much.

 

[Fire-medic]

Please check the routing of your throttle cables! A stuck-open throttle on a VMax is a potentially life-threatening event! Pull-in the clutch, and activate the "Engine-Off" button on your handlebar. Once you get to the side of the road, and you have changed your underwear, check this out thoroughly.

You can find a copy of the Yamaha Service Manual on here, and there are diagrams for the correct placement of cables, wires, brake hoses, vacuum lines, and drain lines.

Anyone want-to post up the link?

 

[lsflp]

I know, it's deadly, it' s only with the hot bike, when it' s cold, she accelerates normally.

 

[Fire-medic]

The links that used to be on here to give you the Factory Service Manual do not appear to be working. I tried Sean's site for VMaxoutlaw, but it doesn't work for the service manual there, either. Anyone got a link that does work?

 

[William_]

Here is a link for the service manual, the throttle cable routing is near the end.

http://vmoa.net/VMX12-Service-Manual01.pdf

Maybe the heat is causing an air leak.

 

[lsflp]

Here is a link for the service manual, the throttle cable routing is near the end.

http://vmoa.net/VMX12-Service-Manual01.pdf

Maybe the heat is causing an air leak.

Can you explain me please a little more.

Thanks

 

[William_]

To check throttle routing you will need to remove the left scoop (one screw on top and one at front near radiator) and possibly the plastic panel holding the relays (I think its held on by 2 or 3 screws). If you look in the manual near the end you'll see pictures of were the cable should be routed. Make sure yours is the same, that operation is smooth and that it snaps back fine.

All of that being correct and the bike still revs itself then check throttle butterflies are opening and closing smoothly and not sticking (remove fake tank and air box lid and you can see them).

 

[lsflp]

To check throttle routing you will need to remove the left scoop (one screw on top and one at front near radiator) and possibly the plastic panel holding the relays (I think its held on by 2 or 3 screws). If you look in the manual near the end you'll see pictures of were the cable should be routed. Make sure yours is the same, that operation is smooth and that it snaps back fine.

All of that being correct and the bike still revs itself then check throttle butterflies are opening and closing smoothly and not sticking (remove fake tank and air box lid and you can see them).

Thanks William, I will check tomorrow and lubricate everything

 

[Oneal Cutinho]

Hi,
My bike is a ‘92 and has the same problem.
As per the manual I checked the throttle line and even lubricated it before closing it up.
Next opened the air box and checked the sliders and it moves freely.
After closing everything back up and taking it for a test run, it still did the same.
Bike warms up and then the throttle stays on a high idle on Nuetral.
When I put it in gear and slowly leave the clutch, the idle goes back to normal.
Not sure if Isflp has the same issue.
I have been thinking of getting my Carb’s completely removed and cleant. Do you reckon this would help sort this problem.

 

[lsflp]

Hi,
My bike is a ‘92 and has the same problem.
As per the manual I checked the throttle line and even lubricated it before closing it up.
Next opened the air box and checked the sliders and it moves freely.
After closing everything back up and taking it for a test run, it still did the same.
Bike warms up and then the throttle stays on a high idle on Nuetral.
When I put it in gear and slowly leave the clutch, the idle goes back to normal.
Not sure if Isflp has the same issue.
I have been thinking of getting my Carb’s completely removed and cleant. Do you reckon this would help sort

Hi,
My bike is a ‘92 and has the same problem.
As per the manual I checked the throttle line and even lubricated it before closing it up.
Next opened the air box and checked the sliders and it moves freely.
After closing everything back up and taking it for a test run, it still did the same.
Bike warms up and then the throttle stays on a high idle on Nuetral.
When I put it in gear and slowly leave the clutch, the idle goes back to normal.
Not sure if Isflp has the same issue.
I have been thinking of getting my Carb’s completely removed and cleant. Do you reckon this would help sort this problem.

I have the same issue, but I clean everything, everything inside of carburetors are new,

The butterfly are freely

 

[[email protected]]

The vmax has a push/pull dual cable setup. If you roll the throttle forward does it close and slow down, or does the issue still persist?
I have a hard time understanding why it would physically stick only when hot?
I'd be more apt to believe its a tuning issue than a physical issue.
When was the last time the carbs were synched?
Any chance you have some air leaks on the carb to intake boots, or v-boost boots?

 

[Radioguylogs]

Hi,
My bike is a ‘92 and has the same problem.
As per the manual I checked the throttle line and even lubricated it before closing it up.
Next opened the air box and checked the sliders and it moves freely.
After closing everything back up and taking it for a test run, it still did the same.
Bike warms up and then the throttle stays on a high idle on Nuetral.
When I put it in gear and slowly leave the clutch, the idle goes back to normal.
Not sure if Isflp has the same issue.
I have been thinking of getting my Carb’s completely removed and cleant. Do you reckon this would help sort this problem.

This one seems like an air leak around the carburators.

Typical symptom is that the idle speed creeps up when you stop at an intersection (when the engine is hot).

An unlit propane torch or lighter fluid can help find any leaks.

-Mike

 

[lsflp]

Now I found another problem, today I tried to start the bike and it was not possible, only heard moving the engine without spark.
I measured the resistance of the pickup coil and got the result of OL.

 

[Fire-medic]

If you're sure that's it, there are aftermarket sources here in the USA you can get one, do a search for pick-up coil, and you should find the threads where they are mentioned. '85-'89 use one type (two senders, with 5 wires in a six-wire plug, purchased as one unit) while the 1990-2007 use another (2 wires in a 2 wire plug). The second one should be your choice if you have a 1992.

1990-2007 Yamaha V-Max VMAX VMX1200 Stator Pick up
Part # P4901 $129.99

Replacement Part: Sometimes this is the only part that fails on your stator. This is the for the pickup coil only as shown. The rubber grommet is not included. Will need to use original rubber grommet from old pulser. To replace it pull the wires from the new pulser through and then attach the provided terminals and connector to the wires.

This part is about $300 through Yamaha!

OE number: 3UF-81670-00-00.
https://www.regulatorrectifier.com/catalog/1990-2007-yamaha-v-max-vmax-vmx1200-stator-pick-up

I agree about the likelihood of a carburetor synchronization and/or air leak being the prior-mentioned causes of a racing throttle.

 

[lsflp]

If you're sure that's it, there are aftermarket sources here in the USA you can get one, do a search for pick-up coil, and you should find the threads where they are mentioned. '85-'89 use one type (two senders, with 5 wires in a six-wire plug, purchased as one unit) while the 1990-2007 use another (2 wires in a 2 wire plug). The second one should be your choice if you have a 1992.

1990-2007 Yamaha V-Max VMAX VMX1200 Stator Pick up
Part # P4901 $129.99

Replacement Part: Sometimes this is the only part that fails on your stator. This is the for the pickup coil only as shown. The rubber grommet is not included. Will need to use original rubber grommet from old pulser. To replace it pull the wires from the new pulser through and then attach the provided terminals and connector to the wires.

This part is about $300 through Yamaha!

OE number: 3UF-81670-00-00.
https://www.regulatorrectifier.com/catalog/1990-2007-yamaha-v-max-vmax-vmx1200-stator-pick-up

I agree about the likelihood of a carburetor synchronization and/or air leak being the prior-mentioned causes of a racing throttle.

This part is good? I burned many years ago the original spare part, here in my country is difficult to get then they made it, I live in Colombia.
I think I have a broken wire, because when I measure it gives me open and if I move the wire a lot it gives me the reading of 8.7Mohm. but the reading its too high.

Thanks frien I will try to import.

 

[Fire-medic]

Sean Morley can help you with shipment if you need, he ships parts all-over the world for our bikes. [email protected]

Yes, when disconnected and measuring between the two pick-up coil wires, your reading should be about 110 ohms at about 20 degrees Celsius.

A common place for the wire to short-out is at the rubber grommet where the wires pass-through the engine side-cover.