Hi Simon
Mmmm, very interesting.
What sort of cranking RPM are you talking about here?
I know it's hard to explain in RPM terms but it needs to be a pretty constant turn over.
I think I read somewhere in the millions of stator threads that it's about 300 to start but but someone else may want to confirm.
Anyway don't dwell on that since it actually starts.
Sounds like you are getting some sort of weird voltage drop.
Without looking into it I couldn't tell you what the standard starter power is rated at but I'll take your word that it's 600W.
Not sure of the CCA rating of your battery either but if it's exceeded volts will drop away.
For exmple (if the Ohms law theory is correct):
600W / 12V = 50A
700W / 12V = 58.3A
But having said all that it's only a couple of amps difference so shouldn't matter a whole lot and when you connect the car battery you should have sh*tloads at a similar voltage.
The booster you are using may be putting out a voltage higher than the batteries which may explain this.
Chuck a voltmeter on while cranking to give you an idea what you are up against.
Also do all the hard start stator voltage tests in the doc related to cranking voltage minimums.
The simple things in life are often overlooked - good cables and good, clean connections.
I killed some mysterious electrical gremlins by running another ground cable from the battery up to the ground cluster/regulators under the tank.
Taffy
I'm not gunna start suckin anything just yet....I've seen your photo :moon: .
Coops
Mmmm, very interesting.
What sort of cranking RPM are you talking about here?
I know it's hard to explain in RPM terms but it needs to be a pretty constant turn over.
I think I read somewhere in the millions of stator threads that it's about 300 to start but but someone else may want to confirm.
Anyway don't dwell on that since it actually starts.
Sounds like you are getting some sort of weird voltage drop.
Without looking into it I couldn't tell you what the standard starter power is rated at but I'll take your word that it's 600W.
Not sure of the CCA rating of your battery either but if it's exceeded volts will drop away.
For exmple (if the Ohms law theory is correct):
600W / 12V = 50A
700W / 12V = 58.3A
But having said all that it's only a couple of amps difference so shouldn't matter a whole lot and when you connect the car battery you should have sh*tloads at a similar voltage.
The booster you are using may be putting out a voltage higher than the batteries which may explain this.
Chuck a voltmeter on while cranking to give you an idea what you are up against.
Also do all the hard start stator voltage tests in the doc related to cranking voltage minimums.
The simple things in life are often overlooked - good cables and good, clean connections.
I killed some mysterious electrical gremlins by running another ground cable from the battery up to the ground cluster/regulators under the tank.
Taffy
I'm not gunna start suckin anything just yet....I've seen your photo :moon: .
Coops
Joined Nov 2004
336 Posts | 0+
North England (Hull)
Hi Simon
Yes, Bundybear is the best man for this - however i am an electrician and certainly know my bikes electrics.
So in the absence of a reply from Bundybear - may i suggest one more test.
Firstly, i'm not convinced your problem is solely electrical, so the following test may prove that.
If you have done exactly this test already, i apologise.
So. Take out plug. Use thick jump leads from your car - engine running, connect neg to starter neg and leave pos free (be careful !). Push start button for 2 seconds, continue pressing, then touch the car pos onto starter pos. Does it spin any faster ?
If it's quite a bit faster IMO yes, it's electrical ...connections, solenoid, charge etc etc.
If it's just a little bit faster IMO it's something else possibly a couple of something else's.
May i suggest the swear word STATOR. How much spark jump have you got - should be 10mm and a nice bright blue colour ...... maybe youv'e only got a little one lol .... You know what that means.
Carb Setup - I know everyone sets up for perfect running whilst totally hot, but in my case, i have my mixture screw a quater of a turn different and it makes a lot of difference to starting. Just my opinion everybody !!
Plug colour after a good run.... Black, Brown, Grey .....all indications.
Anyway - sorry if youve tested all these already
Good luck n let us know
Ady
Yes, Bundybear is the best man for this - however i am an electrician and certainly know my bikes electrics.
So in the absence of a reply from Bundybear - may i suggest one more test.
Firstly, i'm not convinced your problem is solely electrical, so the following test may prove that.
If you have done exactly this test already, i apologise.
So. Take out plug. Use thick jump leads from your car - engine running, connect neg to starter neg and leave pos free (be careful !). Push start button for 2 seconds, continue pressing, then touch the car pos onto starter pos. Does it spin any faster ?
If it's quite a bit faster IMO yes, it's electrical ...connections, solenoid, charge etc etc.
If it's just a little bit faster IMO it's something else possibly a couple of something else's.
May i suggest the swear word STATOR. How much spark jump have you got - should be 10mm and a nice bright blue colour ...... maybe youv'e only got a little one lol .... You know what that means.
Carb Setup - I know everyone sets up for perfect running whilst totally hot, but in my case, i have my mixture screw a quater of a turn different and it makes a lot of difference to starting. Just my opinion everybody !!
Plug colour after a good run.... Black, Brown, Grey .....all indications.
Anyway - sorry if youve tested all these already
Good luck n let us know
Ady
Taff
Thanks for the very misguided vote of confidence, but I can't add much from personal experience. My pre 2001 600 behaves the same as Simon's on e-start. I still tend to use use both e-start & kick together.
Simon
One thing I intended to check out but never did came from Dale Lineaweaver & it makes sense. He said the problem with the SEM system is that the CDI trigger voltage is marginal at low rotational speeds, even though the charge voltage is probably OK.
With a dirty big cylinder (650!) sitting atop minimal flywheel the rotational speed of the crank will vary considerably across the two-revolution cycle (ie between strokes that slow it down & speed it up). Its slowest point is just after compression - exactly when you need it to spark! While the average engine revs at cranking might seem OK, you really need the compression stroke to be almost totally bled away by the decompressor to keep crank speed high at TDC and get sufficient trigger voltage. I suspect that is why these things are so finicky with regard to decompressor lift and timing. You say these seem as OK as they can be.
You probably only need a poofteenth more rotational speed just at the end of compression. While adding another battery might not seem to increase average cranking speed cranking noticeably, it probably markedly increases the starter torque as it slows down against compression.
At light loads, the starter speed really just depends on battery voltage. As the load on it increases, its speed depends on both battery voltage and the effective series resistance in the starter circuit, most of which is inside the batterty itself. A bigger battery (or two in parallel) doesn't increase its voltage, what it does do is decrease its internal resistance.
Assuming you are stuck with the battery type you have (YTZ7A?) and can't change it, anything you can do to minimise resistance in the starter circuit will help. Bigger starter leads and running a dedicated fat copper ground wire from the frame earth connection to the starter body might help a bit but my experience was not that much.
It might also be worth trying bypassing the starter solenoid main contact somehow and seeing if it helps. I suspect the solenoid contacts are probably marginal at cranking currents against compression - the solenoid itself looks pretty small. I don't know how you might do this - perhaps put both positive cables under the one solenoid bolt and try clamping and unclamping the battery ground wire to the engine somewhere to start / stop the starter. If it does help a larger solenoid from something else might be the go?
Also, I think it was Scully? who had a story about fitting other starters a few years back. It might help if you havent found it already.
Scully's thread
If the starter sounds like it is working correctly, it is unlikely that playing with the brushes will help much.
Sorry for the essay - the first post in a long dryspell......
Hope all is well with you, BW
Thanks for the very misguided vote of confidence, but I can't add much from personal experience. My pre 2001 600 behaves the same as Simon's on e-start. I still tend to use use both e-start & kick together.
Simon
One thing I intended to check out but never did came from Dale Lineaweaver & it makes sense. He said the problem with the SEM system is that the CDI trigger voltage is marginal at low rotational speeds, even though the charge voltage is probably OK.
With a dirty big cylinder (650!) sitting atop minimal flywheel the rotational speed of the crank will vary considerably across the two-revolution cycle (ie between strokes that slow it down & speed it up). Its slowest point is just after compression - exactly when you need it to spark! While the average engine revs at cranking might seem OK, you really need the compression stroke to be almost totally bled away by the decompressor to keep crank speed high at TDC and get sufficient trigger voltage. I suspect that is why these things are so finicky with regard to decompressor lift and timing. You say these seem as OK as they can be.
You probably only need a poofteenth more rotational speed just at the end of compression. While adding another battery might not seem to increase average cranking speed cranking noticeably, it probably markedly increases the starter torque as it slows down against compression.
At light loads, the starter speed really just depends on battery voltage. As the load on it increases, its speed depends on both battery voltage and the effective series resistance in the starter circuit, most of which is inside the batterty itself. A bigger battery (or two in parallel) doesn't increase its voltage, what it does do is decrease its internal resistance.
Assuming you are stuck with the battery type you have (YTZ7A?) and can't change it, anything you can do to minimise resistance in the starter circuit will help. Bigger starter leads and running a dedicated fat copper ground wire from the frame earth connection to the starter body might help a bit but my experience was not that much.
It might also be worth trying bypassing the starter solenoid main contact somehow and seeing if it helps. I suspect the solenoid contacts are probably marginal at cranking currents against compression - the solenoid itself looks pretty small. I don't know how you might do this - perhaps put both positive cables under the one solenoid bolt and try clamping and unclamping the battery ground wire to the engine somewhere to start / stop the starter. If it does help a larger solenoid from something else might be the go?
Also, I think it was Scully? who had a story about fitting other starters a few years back. It might help if you havent found it already.
Scully's thread
If the starter sounds like it is working correctly, it is unlikely that playing with the brushes will help much.
Sorry for the essay - the first post in a long dryspell......
Hope all is well with you, BW
Joined Nov 2001
17K Posts | 774+
Ely, England
in my limited experience my first thought was that this was a resistance from a wire or unit and that you were on to something simon? would be great to get to the bottom of this one!
can i also throw in the fact that coastie needed a new (or another) wire from earth to his regulator and at the same time that portugeuse fella was sending out repaired SEM's with a new regulator!
but using your testing methods i would have thought you were narrowing down the area of resistance here.
coastie
it's VD at it's worst that one. wouldn't wish it on anyone - even you! but i gave it to tuts so that's alright then! (LOL!)
regards
Taffy
can i also throw in the fact that coastie needed a new (or another) wire from earth to his regulator and at the same time that portugeuse fella was sending out repaired SEM's with a new regulator!
but using your testing methods i would have thought you were narrowing down the area of resistance here.
coastie
it's VD at it's worst that one. wouldn't wish it on anyone - even you! but i gave it to tuts so that's alright then! (LOL!)
regards
Taffy
Joined Jun 2001
1K Posts | 3+
Berkshire, England
Thanks for all your replies, really appreciate it.
I've got a few things there to go and check out but in the meantime I can confirm:
1. While cranking battery voltage on the YTZ7S only drops to just under 11V at its lowest and is mostly at 11.2V;
2. When I add the booster this increases to 12.2V;
3. Peak capacity of the battery I believe is 130amps so the 50 odd amps I don't think is the limiting factor here;
Off I trot to the garage...........
Simon
I've got a few things there to go and check out but in the meantime I can confirm:
1. While cranking battery voltage on the YTZ7S only drops to just under 11V at its lowest and is mostly at 11.2V;
2. When I add the booster this increases to 12.2V;
3. Peak capacity of the battery I believe is 130amps so the 50 odd amps I don't think is the limiting factor here;
Off I trot to the garage...........
Simon
Joined Jun 2001
1K Posts | 3+
Berkshire, England
Ady said:
Yes, it does and then, no it doesn't :?
.
Ady said:
This depends on how much faster you mean. :wink:
On the first test, the cranking speed increased to that similar to when I used the booster.
This was mirrored by using my YB14L battery as well.
Then I tried it again and it didn't increase cranking speed at all. In fact it was all spinning really nicely on the YTZ7S battery alone. No difference with car battery/booster/YB14L directly connected to the starter.
On testing with spark plug installed there is a significant speed difference when another power source is connected directly to the starter motor a couple of seconds after engaging the start button.
Ady said:
And I always thought size didn't matter :wink:
Spark is fine.
Cheers,
Simon
Joined Nov 2004
336 Posts | 0+
North England (Hull)
Simon
You aint gonna like my verdict.
Auto decomp and / or valves are not quite correct.
But that's my opinion only.
I do not think you have an electrical problem.
Good luck mate ..... plenty of threads about the topic for ya to browse.
Ady
You aint gonna like my verdict.
Auto decomp and / or valves are not quite correct.
But that's my opinion only.
I do not think you have an electrical problem.
Good luck mate ..... plenty of threads about the topic for ya to browse.
Ady
Joined Nov 2004
336 Posts | 0+
North England (Hull)
BTW
Yes i could supply technical details of cable sizes required to carry specific loads. But in practice, the full size is not used because it is only on for a short burst and does not usually get to high temperature, affecting the resistance and therefore the overall diamater required.
Ady
Yes i could supply technical details of cable sizes required to carry specific loads. But in practice, the full size is not used because it is only on for a short burst and does not usually get to high temperature, affecting the resistance and therefore the overall diamater required.
Ady
Joined Nov 2001
17K Posts | 774+
Ely, England
so where does that little rubber mounted article near the starter come into it? the solenoid?
it seems that everything else was under sized or under strength: should i be suprised that if that was upgraded the bike wouldn't be the better for it?
regards
Taffy
it seems that everything else was under sized or under strength: should i be suprised that if that was upgraded the bike wouldn't be the better for it?
regards
Taffy
I too redid my cabling when I added the ground.The former cables were worn out and cheap looking.
I used 6 gauge cables and big fat connectors that I had to flatten in a vise, electric cable around and liquid electric cable to seal.
I used 6 gauge cables and big fat connectors that I had to flatten in a vise, electric cable around and liquid electric cable to seal.
I have had bike in shop 2 times and 1000 US dollars new larger starter and battery . Still no button start . But good oil leak now (nice) Dont have lots choices.Need GOOD shop that can do the job right.
Joined Jun 2001
1K Posts | 3+
Berkshire, England
Ady said:
Hey Ady,
It's not that I don't like your verdict but you don't explain why or how you've come to that conclusion.
I put this thread in Other because on the off chance there may have been be a mechanical element to it.
I do not think it is the decomp or the valves that are causing the problem. Why?
Because on installation of the updated decomp arm, I closed the valve lash up to zero in order to get maximum lift from the decomp lobe and turned the engine over manually to feel any resistance. The resistance at TDC on the compression stroke with the decomp is no worse than the resistance of the valve springs when opening the valves.
On backing off the valves gradually to the right lash, there is no increase in decomp resistance meaning that the decomp is working fine.
I should note on that the old decomp. arm a considerable resistance was present where on manual turnover pressure increased and you could hear a slight psssssstttttt as the air slowly bled out of the exhaust valves.
In addition, a truly mechanical problem would not cause multiple spurious electrical differences in tests such that I am experiencing.
Last night I tried a further test connecting an additional battery to the installed battery - positive to positive, negative to frame and there was no difference in cranking speed. Immediately after I then connected the addition battery directly to the starter and the earth while cranking and there was an increase in cranking speed.
To me that is pointing directly towards an electrical issue, at least partially the solenoid.
But, what is even more interesting is that in swapping out electrical components, like testing against a second stator and other connections I am now getting the continuous higher cranking speed that was previously achieved with the booster (which now makes almost zero difference when connected). And as a note, apart from the decomp arm which went in at the beginning of the tests, I have not kept anything new on the bike.
All the best,
Simon
Joined Jun 2001
1K Posts | 3+
Berkshire, England
As an additional note, I don't recall seeing any specific instructions in previous threads on eliminating the autodecomp (or loose valve adjustment) from the equation on hard electrical starting and therefore could I suggest that the procedure of closing the valve lash and slowly manually turning the engine over to assess resistance, then backing off the valve adjusters to spec lash and assessing any increase in resistance.
If there is noticable resistance in either of those tests, get a new decomp arm and test test that against the old one manually.
Obviously this can also be compared in parallel to electric cranking speed.
Simon
If there is noticable resistance in either of those tests, get a new decomp arm and test test that against the old one manually.
Obviously this can also be compared in parallel to electric cranking speed.
Simon
Hi Simon
Could be a little from column A and a little from column B.
I too believe that most peoples pains come from bad auto decomp and valve adjustments ala my first post.
When you set the valves did you make sure that the decomp systems were disconnected and/or slackened off so they didn't come into play?
Have you measured the valve lift during auto decomp?
Is your valve timing accurate?
One thing you can be sure of - it's either mechanical or electrical.
Don't give up.
Could be a little from column A and a little from column B.
I too believe that most peoples pains come from bad auto decomp and valve adjustments ala my first post.
When you set the valves did you make sure that the decomp systems were disconnected and/or slackened off so they didn't come into play?
Have you measured the valve lift during auto decomp?
Is your valve timing accurate?
One thing you can be sure of - it's either mechanical or electrical.
Don't give up.
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