Dohc Cb750f: possibly a valve issue

irk miller

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datadavid said:
Didnt tesla prefer high voltage dc?
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No, Edison did. In the War of the Currents, Tesla presented AC power and Edison presented DC. At the time, there wasn't a way to deal with power loss for DC, but Tesla had invented an AC transformer, so AC power won out.
 

datadavid

New Member
irk miller said:
No, Edison did. In the War of the Currents, Tesla presented AC power and Edison presented DC. At the time, there wasn't a way to deal with power loss for DC, but Tesla had invented an AC transformer, so AC power won out.
Cool, i know way too little about this stuff.


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irk miller

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Haha. The cool thing about it all, and sorry for all of this thread jacking, is nowadays with wind power and solar power the technology has finally caught up to what Edison was trying to do. It's amazing to think how much he was ahead of his time.
 

SquidHunter

Active Member
So apparently the heat issue will be solved by adding a series regulator. About to test the theory. Ken is sending me one. My bike is running too hot for the ignition to function properly. Everything runs great unless I hit a few redlights.

This is based on information supplied by Gary from power arc, however. It could be power arc trying to pass the buck, but the science made sense so here goes nothing.


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SquidHunter

Active Member
So the series regulator came Wednesday. Let me be the first to say, it’s gigantic and weighs about 4lbs. Wired it up today. Did not solve the heat issue. Did not solve the ignition issue.
I called Ken at Cycle X. He’s had been thinking about the issue a lot, and suggested that I wire the regulator straight to the battery, thinking it may be a noise issue.
I did, and I think it worked ‍♂. Took the bike for a romp through the city. Plenty of rpms, and plenty of redlights. No breakdown since. I’m going to take it on a longer ride Sunday to be for sure.


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SquidHunter

Active Member
Question: what size fuse should I use to run the regulator straight to the battery?


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irk miller

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I wouldn't run a fuse between the regulator and battery, but I'd run them between the battery and everything else.
 

crazypj

Split personality, I fake being smart
Yep, do as Irk says. Running a fuse between regulator and battery will cause a 'runaway' condition if it breaks and fry everything electrical. (you'll have at least 17v but more likely 90+@5,000rpm)
With battery in circuit, the reg has a reference voltage.
 

kopcicle

antidisestablishmentarian
one more time for those that were not paying attention ...


replace the igniter(s) and or pickups until it works
 

teazer

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I'm a little confused by some of the comments. When you talk about the engine being too hot, do you mean the top end or are you talking about the alternator? If the whole motor is too hot, then it's unlikely to be the electrical system. It's more likely to be spark too advanced or running lean.

Have you tried a laser pyrometer to see what sort of temperatures that different parts of thr motor are reaching after a short ride or a longer one?

How was the air temp this time compared to earlier runs. Up here, it's already 10-15 degrees cooler than it was a few weeks ago and that's enough to make a difference.
 

SquidHunter

Active Member
teazer said:
I'm a little confused by some of the comments. When you talk about the engine being too hot, do you mean the top end or are you talking about the alternator? If the whole motor is too hot, then it's unlikely to be the electrical system. It's more likely to be spark too advanced or running lean.

Have you tried a laser pyrometer to see what sort of temperatures that different parts of thr motor are reaching after a short ride or a longer one?

How was the air temp this time compared to earlier runs. Up here, it's already 10-15 degrees cooler than it was a few weeks ago and that's enough to make a difference.
I’m in Birmingham Alabama. The air temperature is hot. 80-90 degrees. I’m running a slight touch lean, I’m almost certain. There was a setback, and I haven’t put it on a dyno yet. I wanted to dyno it, and jet from there. However, I’m still running the stock airbox/filter.

The series regulator was supposed to cause less stress on the charging system. There’s some thermal imaging of bikes running with and without, and apparently it causes them to also run cooler ‍♂. But, nasa isn’t knocking down my door for electrical advice.


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SquidHunter

Active Member
kopcicle said:
one more time for those that were not paying attention ...


replace the igniter(s) and or pickups until it works
There’s no igniters and no pickups. The ignition is power arc.

Noise interference is the issue I’m having


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SquidHunter

Active Member
irk miller said:
I wouldn't run a fuse between the regulator and battery, but I'd run them between the battery and everything else.
Well, incidentally, this is how it’s now wired. My plan is to get it running right, then break everything down so I can build it right. I’ve got to weld some mounting tabs, and paint the frame and tank/side covers. Suspension etc etc...

So I’ve done a “temporary” harness to sort it out. I wanted to start from nothing, and figure it out. Can’t even tell you how much I’ve learned.


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SquidHunter

Active Member
teazer said:
I'm a little confused by some of the comments. When you talk about the engine being too hot, do you mean the top end or are you talking about the alternator? If the whole motor is too hot, then it's unlikely to be the electrical system. It's more likely to be spark too advanced or running lean.

Have you tried a laser pyrometer to see what sort of temperatures that different parts of thr motor are reaching after a short ride or a longer one?

How was the air temp this time compared to earlier runs. Up here, it's already 10-15 degrees cooler than it was a few weeks ago and that's enough to make a difference.
The original theory was that engine temperature was tripping a safety mechanism in the ignition. It’s built in to prevent a “meltdown”.......supposedly. Turns out, it’s probably a noise issue due to the regulator being wired to the starter solenoid (ie: like “stock”). Wiring the regulator strait to the battery solves that....apparently ‍♂

All new information to me, and most of the technical is over my head. But if it works, I’m in.


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teazer

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Too many noisy electrons will create issues. Not sure about the wiring change though. Battery to starter and wire from that same terminal to the regulator. How does that differ from a wire direct from the battery to the regulator? And what is the noise source? I don't know about electrical issues to pass judgement - just trying to understand and clear the smoke to see what is actually happening.

I get that the ignition might have some sort of thermal overload protection but it made no sense that the charging circuit was a cause of overheating. Good to see that theory has been taken off the table. Keeping in mind that I wouldn't know an electron if I ran it over, I wonder if that new alternator might be generating waves (ripples) in the DC circuits that caused the ignition to freak out. Maybe the new regulator acts as a smoothing device in some way.

BTW, most bikes now seem to have a 30 amp fuse built into the starter solenoid wiring between the battery and everything else. If it blows, all power to all circuits is cut, so no more engine generating power, so I'd guess that is not an issue.
 

irk miller

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One advantage to running a fuse per individual circuit vs. a breaker for the whole harness is being able to isolate an issue easier. If my headlight fuse blows, I know where to look because the fuse told me. If a circuit breaker blows, I'm checking the whole harness hoping I don't test the headlight circuit last.
 

SquidHunter

Active Member
teazer said:
Too many noisy electrons will create issues. Not sure about the wiring change though. Battery to starter and wire from that same terminal to the regulator. How does that differ from a wire direct from the battery to the regulator? And what is the noise source? I don't know about electrical issues to pass judgement - just trying to understand and clear the smoke to see what is actually happening.

I get that the ignition might have some sort of thermal overload protection but it made no sense that the charging circuit was a cause of overheating. Good to see that theory has been taken off the table. Keeping in mind that I wouldn't know an electron if I ran it over, I wonder if that new alternator might be generating waves (ripples) in the DC circuits that caused the ignition to freak out. Maybe the new regulator acts as a smoothing device in some way.

BTW, most bikes now seem to have a 30 amp fuse built into the starter solenoid wiring between the battery and everything else. If it blows, all power to all circuits is cut, so no more engine generating power, so I'd guess that is not an issue.
My solenoid has a 30amp fuse. My original thinking was that this would be great, considering the stock harness plugs in at the solenoid. But, the stock ignition isn’t effected by noise.

Apparently both regulators are producing noise. But, wiring it straight to the battery eliminates that noise ‍♂. This is the first time I’ve heard this, but......

Tomorrow I’ve got some guys together, and we’re going to shred the surrounding area. I’ll know for sure if it’s fixed tomorrow. No holding back


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SquidHunter

Active Member
irk miller said:
One advantage to running a fuse per individual circuit vs. a breaker for the whole harness is being able to isolate an issue easier. If my headlight fuse blows, I know where to look because the fuse told me. If a circuit breaker blows, I'm checking the whole harness hoping I don't test the headlight circuit last.
You are exactly right. My plan is to run a m-unit. Just trying to work out the bugs for now.

If my headlight fuse blows, my fuse is my headlight.....

I’m going to run LEDS and all that, so I’m not particularly worried about it at this time. I’ve blown that 30amp solenoid fuse about 5 times messing with the electrical. When I say messing, I mean just that. It’s been a total mess. As I expected, I’m walking away with a ton more knowledge though.


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