stalling max

[Firerider]

First time poster. Very pleased to find a site with so many v-maxers. I have an 85 that is pretty much stock other than the R1 brakes and Sportmax seat.
Recently my happy little hot rod (still talking about the bike, right) has been developing a problem that seemed to occur after riding at highway speed for a while and then slowing to in town speed. The motor would start to stumble and run rough. A couple of weeks later it would stall if I had to stop at a light too long. Late last season it began the same symtoms after around 15 minutes of riding and got progressively worse. Now this problem begins shortly after warm up. It starts up fine (with choke when cold) and idles fine for a few minutes then begins to run progressively rougher until it stalls.
Any ideas or similar experience. Thought maybe coils, but it's got 4 of them and if one failed I wouldn't think it would cause it to stall. I guess that leaves electrical or carburation. I began a maintanance check on it but then found this site and thought I would throw it out there for your concideration.
The VBoost room may not be the correct place to start but I never noticed til I got this far along so i am going to stick with it.

 

[naughtyG]

The most common reason for this is dirt in the idle jets and other small such places in the carbs.

First port of call - look up (search) the Shotgun and the Peashooter cleaning methods. Both are easy and may just sort you out.

On my '86 when it displayed the exact same symptoms, the Shotgun helped a lot, but it kept coming back after a few weeks in the FL heat so eventually I tore through my carbs, cleaned them up properly and replaced a few worn our rubber parts, and then it ran like a dream.

Check out my 'how to' posts with full pictures if you fancy doing the same.

I'd also recommend checking out the insides of your fuel tank for rust - if any at all it WILL need treating.

 

[mattness]

check your regulator bro

 

[SpecOps13]

Drain your carbs one at a time into a clean jar or cup. See if there are tiny rust particles in any of them. Run some sea foam in your gas for a while and drain the carbs to check them at intervals if you find these particles. Also, wouldn't hurt to check your electrical system and do some solder mods on connectors that may have become corroded. Another thing to check is to run the bike for a while and take the gas cap off. If you hear a whoosh sound, the fuel tank vent system is blocked at some point... generally a Pin can be used to clear it... Let us know if any of this is unclear or you do find something... Good Luck....

Welcome to The VMax Forum......

1972

 

[88vmx12]

dirty carb bowls +1 idleing circuit in the carbs is dirty

Gannon

 

[VMAX1260]

you can also check your fuel pump. can you hear it working when turn the switch to run. if yes you should check the voltage that goes to the fuel pump. in my previous bike i had the same problem. it was working fine and then it started stalling . the voltage of the fuel pump was sometimes 12v sometimes less. when it was less the fuel pump didnt work as it should and eventually my bike stoped. one quicky check is when your bike stalls again ,turn the bolts that you empty the fuel from the bowls from the small black hoses that come out in each carb. if there is no fuel coming out .... fuel is not coming in your carbs.
but as all the other said it maybe dirt somewhere but it isnt easy this to occure in the same time and four carbs start doing this thing so your bike would stall.

 

[jfeagins]

Ditto on checking the output of the R/R. Low voltage can cause serious stumbling after warmup while trying to get it to idle too.

 

[dmax1]

Check the fuel filter? Or the diaphram (rubber check valve) located inside the fuel pump. They sometimes fall out. :confused2:

 

[RaWarrior]

I suspect your ignition box is taking a dump. Your 85 has the "old" analog style (digital in 90-up), and the analog ones are not super reliable. As the box gets old, now over 25 years, conductors and transistors have broken down and don't conduct as well as they used to. Wires, coils, the box itself, the whole system. That generates more heat from the higher current passing through. As the engine runs longer, the heat builds up and stuff just starts to wack out in the TCI. The spark gets weak/intermittent, and eventually the motor stalls.

Does it start right back up and run fine after waiting a few minutes? Happen quicker if the bike is left idling (stationary) instead of moving?

 

[Firerider]

First time poster. Very pleased to find a site with so many v-maxers. I have an 85 that is pretty much stock other than the R1 brakes and Sportmax seat.
Recently my happy little hot rod (still talking about the bike, right) has been developing a problem that seemed to occur after riding at highway speed for a while and then slowing to in town speed. The motor would start to stumble and run rough. A couple of weeks later it would stall if I had to stop at a light too long. Late last season it began the same symtoms after around 15 minutes of riding and got progressively worse. Now this problem begins shortly after warm up. It starts up fine (with choke when cold) and idles fine for a few minutes then begins to run progressively rougher until it stalls.
Any ideas or similar experience. Thought maybe coils, but it's got 4 of them and if one failed I wouldn't think it would cause it to stall. I guess that leaves electrical or carburation. I began a maintanance check on it but then found this site and thought I would throw it out there for your concideration.
The VBoost room may not be the correct place to start but I never noticed til I got this far along so i am going to stick with it.

I suspect your ignition box is taking a dump. Your 85 has the "old" analog style (digital in 90-up), and the analog ones are not super reliable. As the box gets old, now over 25 years, conductors and transistors have broken down and don't conduct as well as they used to. Wires, coils, the box itself, the whole system. That generates more heat from the higher current passing through. As the engine runs longer, the heat builds up and stuff just starts to wack out in the TCI. The spark gets weak/intermittent, and eventually the motor stalls.

Does it start right back up and run fine after waiting a few minutes? Happen quicker if the bike is left idling (stationary) instead of moving?

Yes it will start up just fine but will not run for long. Doesn't seem to matter anymore if your riding or if it is at idle. It will however run once you get moving but you have to increase the rpm to keep it going at idle.

 

[Firerider]

Thanks to all for the help. I will start with the easiest possibilities and work my way through.
I wrote a big long speel but I guess I timed out so I'll try to keep it shorter in the future

Later.

 

[Redbone]

Thanks to all for the help. I will start with the easiest possibilities and work my way through.
I wrote a big long speel but I guess I timed out so I'll try to keep it shorter in the future

Later.

You can avoid that issue of losing posts by first typing it in a notepad/ wordpad/ Word document first then cut and paste into the forum.

 

[Firerider]

Hello All. Thought I would give an update on my stalling problem.

I have checked all the electrical connections and cleaned the dirty (greenish) ones, which there were a few of, and used no-corode on them. Hard soldered a couple. I ruled out the carbs as I had a 2nd set which I installed. I also replaced the CDI box and installed new plug wires.
This week I insured it and took it out on the road for aabout a 20 mile run. It seemed to be working flawlessly until I had to sit at a 3 way light for about a minute. As it sat idling it began to miss intermittantly but was not nearly as bad as before. I am obviously still missing something in my trouble shooting. Any more ideas ??
Would a weak stator cause issues at idle? It runs very well except when it sits idling too long.

Ken.

 

[alorio1]

Check voltage at the battery at different RPMs, you are probably low on voltage from your charging system. When voltage gets low your bike will miss and stumble because you don't have enough voltage to supply CDI and coils with proper voltage, this is very noticeable when cooling fan comes on which taxes electrical system even more. I had to do the R1 rectifier mod to overcome the same problem you are having. Older Maxes have an insufficient charging system and has to be upgraded to the newer Rectifier by Yamaha or do the R1 mod which is the best of the two in my book. Check all your connections , especially grounds, and see if you can get charging system to put out more voltage.

 

[Firerider]

Check voltage at the battery at different RPMs, you are probably low on voltage from your charging system. When voltage gets low your bike will miss and stumble because you don't have enough voltage to supply CDI and coils with proper voltage, this is very noticeable when cooling fan comes on which taxes electrical system even more. I had to do the R1 rectifier mod to overcome the same problem you are having. Older Maxes have an insufficient charging system and has to be upgraded to the newer Rectifier by Yamaha or do the R1 mod which is the best of the two in my book. Check all your connections , especially grounds, and see if you can get charging system to put out more voltage.

Thanks for the info.
I was just reading on another thread that others are having similar problems. I already upgraded to the R1 R/R and I am Going to order a new stator as well from Rick's Stators. I have checked all my connections and grounds but can only get around 12.9 volts across the battery

Thanks again.

 

[alorio1]

I think you are moving in the right direction, I would solder the stator wires and go directly to the battery with RR connection. Mine holds 14.4 @ 3k with fan on and I have no more stumbling issues.

 

[Miles Long]

Hello All. Thought I would give an update on my stalling problem.

I have checked all the electrical connections and cleaned the dirty (greenish) ones, which there were a few of, and used no-corode on them. Hard soldered a couple. I ruled out the carbs as I had a 2nd set which I installed. I also replaced the CDI box and installed new plug wires.
This week I insured it and took it out on the road for aabout a 20 mile run. It seemed to be working flawlessly until I had to sit at a 3 way light for about a minute. As it sat idling it began to miss intermittantly but was not nearly as bad as before. I am obviously still missing something in my trouble shooting. Any more ideas ??
Would a weak stator cause issues at idle? It runs very well except when it sits idling too long.

Ken.

Ken(and everybody)
The more posts I see regarding under/overcharging issues - at rest, idle, at speed, etc, the more I'm convinced all first gen. maxes should be equipped with a permenant on-board voltmeter (currently being discussed in the V-boost forum) Relatively inexpensive add-on, easy to hook up. Might easily prevent a stalling at lights situation (undercharging) or a smoked stator-($$$$!), because of an overcharging condition.
Thik I'll start shopping for one. That Kuriycan coloured light unit looks quite groovy, and by all accounts performs well.
Cheers, Miles

 

[Firerider]

ken(and everybody)
the more posts i see regarding under/overcharging issues - at rest, idle, at speed, etc, the more i'm convinced all first gen. Maxes should be equipped with a permenant on-board voltmeter (currently being discussed in the v-boost forum) relatively inexpensive add-on, easy to hook up. Might easily prevent a stalling at lights situation (undercharging) or a smoked stator-($$$$!), because of an overcharging condition.
Thik i'll start shopping for one. That kuriycan coloured light unit looks quite groovy, and by all accounts performs well.
Cheers, miles

agreed......

 

[SpecOps13]

It's great to watch this forum hack away at problems that may never be solved otherwise... Good Luck.....

 

[Autodetalhe]

i have 1998 vmax full power and does the same thing after good riding, the carbs was clean and sync, i know she siting on garage abour 3 or 4 years