loosing power

[fret not]

I'm glad you got it sorted out and all is well. :)

[Guerrero]

Hello every one.I am back! :)
Finally had time to work with bike.
At last carbs are done,with stock jetting.nicelly sinced,and now it runs smooth.
Have one little problem left,and cant figure out,what is the problem-
Bought a new battery-yuasa company.So when engine is cold it starts from half turn.and every one are satisfied:)But as soon as the engine gets hot,it is almost impossible to start the bike.and the by that i mean,not that starter turns for long time,and nothing is going on,BUT,it seems like the battery has not enough power,like it would be quite empty.Just as engine gets cold/er starts from half turn.
Any ideas?Maybe problems with starter?and as it gets hot it is harder to turn?

Have a great day,Tom

[QBS]

What is the starters' history?

[Guerrero]

2 or 3 years ago used starter's repair kit from ebay,because the coils went dead(got too short)So changed everything that came in the kit-coils,rubbers,and i do not know how to call them in english-metallic kind of bearings,in which the starter it self and little gears are turning.I have not made a lot km from that time because of all my other troubles.But i do not know,what is going on in the starter at the moment.Have idea,to take it off and check

[QBS]

With engine hot, connect a 12v auto battery directly to the starter motor.  +lead to the starter motor power point, - lead to the Vision engine, bike in neutral.  See what happens and let us know.  If the starter motor is in good condition the engine should crank fast.

[Guerrero]

ok,thanks.will try

[Guerrero]

So,now i have come to something-even that i rebuilt starter few years ago,it seems that the main the rotor it self,or maybe main bearings are worn out.I have not yet opened the starter,just removed it.
So,when the engine gets hot and i need to start it,starter axle is changing the angle and shortening the battery and everything.Good that i pfound out it just now,so i hope i can save my newly bought Yuasa batt,.

One more question,how much voltage would be good from stator at 5k rpm??i got about 90v between each wires.Some say 50 is good,some say 150. At idle i got about 30-35v.And i have actually some charging problems at the moment.Because i have tried new chinese r/r-it gave me somewhere 13,4 at 5k.Put on cbr900 r/r and got without lights on 13.7-13.8,with lights 13,6-7 i Guess i need more

[Guerrero]

Little update of situation,if some one is interested.
Engine still runs great:)
Problem is still there,i cant start engine while hot.Tried different batteryes,and only "hells machine"-soviet launch system that gives 15v can start the engine.
I do not want to say any bad word about Tiger,NO.,but his wire set of power leads was a dissapointment...i put them on.and the negative wire connector just came off,it was held in place just by rubber kembrik(the rubber thing that closes the connection place)so the connector just came off.there where no marks of solder or anything.too bad,40 usd thrown in to trash.but you know,how they say-"the poorman pays twice" so.after i put back negative lead from some honda.And changed battery to starter relay wire too.everithing looks nice now.Soldered the R.R unit,and now without light i get up to 13.9 V chargin.Wich is nice.

Now still need to understand why starter has problems to start.(the engine is turning freely,so not a problem of that.)
Oh and had to change gears in the starter motor,because the bearing(not bearing but ring things that are in those gears)were worn out.Changed them and the big gear around them.and now the motor is turning good.

Have a good day,comments are Welcome ,Tom

[The Prophet of Doom]

Little update of situation,if some one is interested.
Engine still runs great:)
Problem is still there,i cant start engine while hot.Tried different batteryes,and only "hells machine"-soviet launch system that gives 15v can start the engine.
I do not want to say any bad word about Tiger,NO.,but his wire set of power leads was a dissapointment...i put them on.and the negative wire connector just came off,it was held in place just by rubber kembrik(the rubber thing that closes the connection place)so the connector just came off.there where no marks of solder or anything.too bad,40 usd thrown in to trash.

The measure of a manufacturer is not just the quality of their product, but how they handle things when they go wrong (which they inevitably do from time to time).  Did you bother to talk to Tiger about this issue?

[Guerrero]

no,i did not.this happened today.I bought the wire set little less than year ago.I do not see any reason for talking to Tiger.As i said.i have nothing against him.I do not say,that he is bad,or that he makes bad wire sets.No.Just thing happened with me.its a pitty

At the moment i am more interested,does really nobody have any ideas,or solution about my starting problem?
I have a theory,maybe thermo sensor or switch is faulty?because bike runs quite in red line,when the fan kick's in.Maybe some how the switch does not let engine to crank,while hot?

[The Prophet of Doom]

There's no thermo switch.

You can easily isolate - there are only a few items in the circuit
jumper leads straight to starter
a starter relay click
12V at starter relay
etc

[Guerrero]

it seems that starter motor is bad. :( any ideas how much can cost starter motor?and maybe there are any other model match???

[The Prophet of Doom]

Pull the starter motor apart (again) and run the tests in haynes.  You may be able to clean up the copper and possibly new brushes from a rebuild kit (ebay)

[Guerrero]

copper has been already cleaned.and everithing including brushes that came with repair kit i already installed 2 years ago.Since then i have not ride a lot.

[QBS]

In the planetary reduction gear box, make certain that the centers of the posts that the outer/planetary gears ride on are directly across from each other through the center of the center/sun gear post.  If the outer gears are even one tooth out of place the starter will not turn as freely as it needs to.

[Guerrero]

ok,thanks.will check that.

[b_racuda]

Personally I would check:

- battery is ok
- regulator works fine when running
- spark plugs are ok
- mixture and idling are correctly adjusted
- valves are correctly adjusted

Check that choke cable works fine so that when you put if off the choke really goes off from the carburetors. This may cause that engine starts good in cold but not at all when hot.

Check also that idling and mixture are correctly adjusted. Start engine and then start to turn mixture screw until the rpms stop rising and then take a little bit back. Same for the both carburetors. Be patient when turning, wait a moment after turning. At this stage don´t mind if the rpms are too high or too low. When the mixture is correctly adjusted adjust just the idling for the correct rpms.

Valves are also quite common reason with starting problems when motor is hot. If they are too tight adjusted they don´t close but stay open when the motor is hot. And when the motor is cooled they work fine.

[Guerrero]

As i said.Battery is 1 month old.Have tried 4 batteries with this problem.R?R is working good.Charging sistem goes up to 14.0v now.plugs are good.Mixture and everithing about carbs are smooth.Just synced.As i said,problems is not that engine cant start,even that starter motor is turning(like it would just overfloating with fuel) No.the oproblem is that starter motor just is not turning the engine when it gets hot.Just like half turn and stops,half turn and stops.Like not enough power.And starter motor gets very hot of that really fast,And btw drains battery with this.
I figured out,that i just have to change the starter.Because everithing has been changed and adjusted as ist should be.It is not that i am working by meself.Last 2 weeks or even more like 4 mechanics(and really good ones).and electrycian are working on it :)So everithing is set up as good as it can be for bike 30 years old.But starter motor has come to an end

[Rikugun]

Poor performance when hot may indicate a bad commutator and/or armature winding(s). "Replacing parts does not a rebuild make"
The commutator needs to be cut smooth and the insulation undercut a bit. You can also do ohm checks from segment to segment to look for bad windings.

[Guerrero]

you mean commutator of starter motor,right?so called anker?
It is hadr to tell what is the problem.The repair kit has been used on motor.The commutator has been checked on big stand for electromotors.
My guess is that,the starter motor some was broken fizikally,the part where gearbox sits.the one "ear" where bolt goes was broken.And then reweld.and possibly some how changed geometry.so when engine gets hot and it gets harder to turn it,startger motor some how fails?
worst thing is that because this bike is so rare,there is no chance of experimenting..
I could just take starter motor from different bike and try it out.But where will i get it? :)
Does any other starter motor fit Vision?or no?