Vmax first Gen hot start issue

[telim2]

Hello to every one in here. I bought a used vmax four months ago and all looks good the bike except that it doesn't start whenever the engine is hot. I have replaced the battery hoping this will fix the issue but endup getting same hot start issue with the new battery. I search online and found this forum only to read here that the hot start problem is a major issue with first gen vmax having 2 starter motor. My mechanic check the starter motor on the vmax and found out it as 4 starter motor which means i do not need any upgrade of the starter motor. We have few mechanic that fix motor cycles with higher cc over here and am the only one that have vmax in my locality. I would like experience vmax users on these forum to come to my aid on what else to do so as to fix the hot start issue. I wil really appreciate your advice. Thanks

 

[davidon]

Hello to every one in here. I bought a used vmax four months ago and all looks good the bike except that it doesn't start whenever the engine is hot. I have replaced the battery hoping this will fix the issue but endup getting same hot start issue with the new battery. I search online and found this forum only to read here that the hot start problem is a major issue with first gen vmax having 2 starter motor. My mechanic check the starter motor on the vmax and found out it as 4 starter motor which means i do not need any upgrade of the starter motor. We have few mechanic that fix motor cycles with higher cc over here and am the only one that have vmax in my locality. I would like experience vmax users on these forum to come to my aid on what else to do so as to fix the hot start issue. I wil really appreciate your advice. Thanks

https://imageevent.com/jkvmax/vmaxgroundcablekit;jsessionid=qaph7v31l1.eagle_s

 

[85vmax]

What year is the bike.

 

[02GF74]

What do you mean by doesn't start?

What do you mean by hot, up to running temperature?

Does the engine turn over? If yes, is it at the same speed as when cold?

Also if responded yes do you have a spark and is the fuel pump running?

Are carbs set up correctly, ie the choke is not on when trying to start when hot?

Have you tried attaching a second battery to try to start it?.

 

[Zeus36]

Welcome to the site!
Please take a look at this for hot starting issues:

See the first section that reads: "My Vmax cranks slowly or won't start when hot"

How to: Fix your Vmax's low voltage or charging problems

 

[telim2]

What year is the bike.

2001 yamaha vmax 1200

 

[telim2]

What do you mean by doesn't start?

What do you mean by hot, up to running temperature?

Does the engine turn over? If yes, is it at the same speed as when cold?

Also if responded yes do you have a spark and is the fuel pump running?

Are carbs set up correctly, ie the choke is not on when trying to start when hot?

Have you tried attaching a second battery to try to start it?.

What do you mean by doesn't start?
it starts but only when the engine as cool down alot when hot i can only start it when i jump start

Does the engine turn over? If yes, is it at the same speed as when cold?

when the engine is cold the starter motor turns the engine and starts it but when hot the starter fails to start the engine

Also if responded yes do you have a spark and is the fuel pump running?
The mechanic said the fuel pump and the spark plug works perfectly

Are carbs set up correctly, ie the choke is not on when trying to start when hot?
choke is setup perfectly and not on when engine is hot.
Between the yamaha vmax was manufactured in 2001

 

[telim2]

Welcome to the site!
Please take a look at this for hot starting issues:

See the first section that reads: "My Vmax cranks slowly or won't start when hot"

Thank you @Zeus36 will take a look at the link

 

[telim2]

https://imageevent.com/jkvmax/vmaxgroundcablekit;jsessionid=qaph7v31l1.eagle_s

Thanks will take a look at the guide. I hope to get the issue solved once and for all

 

[lastwhiteman]

After I changed out my coolant thermostat for a new one the hot start issues I had ceased to exist.

 

[telim2]

After I changed out my coolant thermostat for a new one the hot start issues I had ceased to exist.

I will look into getting the coolant thermostart of vmax. Were is it located on vmax and were do you buy it from?

 

[MaxMidnight]

After I changed out my coolant thermostat for a new one the hot start issues I had ceased to exist.

Perhaps I'm missing something but unless you undid the starter cable then I can't imagine how the t.stat would affect starting. If you did undo the starter lead then that is more likely to have affected a cure.

I will look into getting the coolant thermostat of V Max. Were is it located on V Max and were do you buy it from?

First rule of diagnosis - do not rely on others (well meaning) suggestion unless you have proved that your bike has the same problem.

IMO you would be wasting time and money by replacing the t.stat, The t.stat housing is at the front of the engine on the RH side.
If it starts OK when cold then I would doubt that it is a battery or charging problem.

From what you say in post #7 the engine does not turn over when hot?

Out of curiosity how did you establish it has a four brush motor?
The external features are 2-brush starter marked SM-229C, 4-brush starter (93-94 on) SM-13.
The field coils in the 2 brush starter are attached by 2 cross head bolts which are visible on the outside of the centre section of the motor. The 4 brush motor has no visible cross head bolts.

I would start by cleaning all earth points and both ends of the cable from the solenoid to the motor.
If that doesn't help then you may need to strip the started and check the condition of the brushes (service limit is 5mm), commutator (service limit is 27mm) and mica depth (0.7mm below commutator bars).
You should also check for continuity between each bar and all of the others. There should be infinite resistance between the commutator bars and armature shaft.

 

[02GF74]

We've established that the starter motor does not turn the engine over when hot.

When attempting to start when hot, does the headlamp light dip? Does the starter solenoid click? Is there any noise from the starter?

Staying the bleeding obvious but the difference in state between starting and non starting is that certain items have got hot.

Heat causes metal objects to expand so any clearance between moving parts becomes smaller, that for example could cause something in the starter motor to jam.

Another effect is that the resistance of metals increases which, for example would result in less power getting to the starter motor.

Like MM, I do not see how a thermostat would change things.

Are you able to run the engine for 5 minutes, stop it and try to start, and repeat. In theory it should reach a point where it is too hot too start. You may be able to hear something that may indicates some component is dragging.

Another thing to try is put the bike on centre stand, in gear and turn the rear wheel forwards, done when cold and hot (not starting condition) and see if there is any difference in the effort needed to turn the engine. This would rule out any engine issues.

Are you able to measure voltage across the starter terminals when cold/hot?

Are you able to access the positive starter motor terminal to connect a jump lead to the position of the battery.

BTW my gut feeling is that it is the starter, write up to service it is here.

https://www.vmaxforum.net/threads/h...or-and-eliminate-hot-starting-problems.12367/

 

[lastwhiteman]

Perhaps I'm missing something but unless you undid the starter cable then I can't imagine how the t.stat would affect starting. If you did undo the starter lead then that is more likely to have affected a cure.



First rule of diagnosis - do not rely on others (well meaning) suggestion unless you have proved that your bike has the same problem.

IMO you would be wasting time and money by replacing the t.stat, The t.stat housing is at the front of the engine on the RH side.
If it starts OK when cold then I would doubt that it is a battery or charging problem.

From what you say in post #7 the engine does not turn over when hot?

Out of curiosity how did you establish it has a four brush motor?
The external features are 2-brush starter marked SM-229C, 4-brush starter (93-94 on) SM-13.
The field coils in the 2 brush starter are attached by 2 cross head bolts which are visible on the outside of the centre section of the motor. The 4 brush motor has no visible cross head bolts.

I would start by cleaning all earth points and both ends of the cable from the solenoid to the motor.
If that doesn't help then you may need to strip the started and check the condition of the brushes (service limit is 5mm), commutator (service limit is 27mm) and mica depth (0.7mm below commutator bars).
You should also check for continuity between each bar and all of the others. There should be infinite resistance between the commutator bars and armature shaft.

Sometimes it's the simple solution to a seemingly complex problem. My Max would stall while sitting at hot idle and not start until cooling off a bit or getting a push. I checked battery, starter, stator, wiring, and then thought about the thermostat. The temp gauge didn't show it to be excessively hot so wasn't at the top of my diagnosis list. I, at one time thought this was a forum to share ideas, I just shared my experience, sorry.

 

[MaxMidnight]

Sometimes it's the simple solution to a seemingly complex problem. My Max would stall while sitting at hot idle and not start until cooling off a bit or getting a push. I checked battery, starter, stator, wiring, and then thought about the thermostat. The temp gauge didn't show it to be excessively hot so wasn't at the top of my diagnosis list. I, at one time thought this was a forum to share ideas, I just shared my experience, sorry.

No need to appologise but from your original post it was not clear (to me at least) the link between the t.stat and hot starting. Thank you for the additional information.

From what you have said in you last post suggests that it was a hot soak issue and that the replacement 'stat meant the motor ran cooler?
Was the motor turning over normally when it wouldn't start?
Did you measure the the opening temperature of the 'stat you took out to establish if it was out or specification?
Do you have the front and rear shields over the top of the heads in place?
After you changed the 'stat what difference did the coolant temperature indicator show?

I ask the above as they are some of the questions I would be asking during my diagnosis which would help me zoom in to what is causing the problem.

I always encourage those with issues to diagnose the problem by establishing the facts of the matter on their bike rather than slavishly follow what worked for someone else. They may strike lucky but they may also waste time and money.

 

[lastwhiteman]

No need to appologise but from your original post it was not clear (to me at least) the link between the t.stat and hot starting. Thank you for the additional information.

From what you have said in you last post suggests that it was a hot soak issue and that the replacement 'stat meant the motor ran cooler?
Was the motor turning over normally when it wouldn't start?
Did you measure the the opening temperature of the 'stat you took out to establish if it was out or specification?
Do you have the front and rear shields over the top of the heads in place?
After you changed the 'stat what difference did the coolant temperature indicator show?

I ask the above as they are some of the questions I would be asking during my diagnosis which would help me zoom in to what is causing the problem.

I always encourage those with issues to diagnose the problem by establishing the facts of the matter on their bike rather than slavishly follow what worked for someone else. They may strike lucky but they may also waste time and money.

No worries.
The issues I was having was, for instance stopped at a traffic light with the ambient temp at 80 degrees F and above, the engine would stall and no, the temp gauge would not be spiked but at a little below the max reading. This was not uncommon prior to my hot starting issues, seemed to be where it wanted to run. When the bike would stall it seemed as an electrical problem ( I did have the main fuse blow once unrelated to this issue so I suspected something along that line ) because it acted like a dead battery, wouldn't turn over or very slow starter engagement. When it occurred to me to check the thermostat I did check the old one and found it to be a non-opener. That may explain why I had no issues while riding ( certain amount of air cooling ) vs stopping and overheating. I did have the front heat shield in place but had removed the rear for some reason I cannot remember. The difference in the temp gauge, it now rarely goes above normal and sometimes stays just below the normal mark.
I think maybe in the past that the thermostat would open just enough to appear somewhat normal but that it just quit opening after a while.
I hope this answers your questions and helps someone with similar issues.

 

[MaxMidnight]

No worries.
The issues I was having was, for instance stopped at a traffic light with the ambient temp at 80 degrees F and above, the engine would stall and no, the temp gauge would not be spiked but at a little below the max reading. This was not uncommon prior to my hot starting issues, seemed to be where it wanted to run. When the bike would stall it seemed as an electrical problem ( I did have the main fuse blow once unrelated to this issue so I suspected something along that line ) because it acted like a dead battery, wouldn't turn over or very slow starter engagement. When it occurred to me to check the thermostat I did check the old one and found it to be a non-opener. That may explain why I had no issues while riding ( certain amount of air cooling ) vs stopping and overheating. I did have the front heat shield in place but had removed the rear for some reason I cannot remember. The difference in the temp gauge, it now rarely goes above normal and sometimes stays just below the normal mark.
I think maybe in the past that the thermostat would open just enough to appear somewhat normal but that it just quit opening after a while.
I hope this answers your questions and helps someone with similar issues.

Thank you for the clarification.

 

[telim2]

Thanks to all that contributed to these thread. Got the hot start issue fixed after buying a lithium battery with high cc. It now starts within few secs when hot. Seems my crankshaft is damage and will need to be replacement hope i get someone that sell vmax parts on these forum.