Hall Effect Sensor replacement - use same alignment position?

[schrocketeer]

When replacing a Hall Effect Sensor, if I carefully mark the orientation of the old one, and line up the new one to the same marks, do I have to re-time it?
1986 K100RT OEM sensor, replacing with new Euromotoelectrics BOIgnSen-K033EDL

Related: is the bike's timing tightly coupled to the sensor itself, or the position of the sensors relative to the bike's rotating, timing disk?

[Laitch]

You shouldn't need to time it again if you've been careful during your replacement procedure, and the initial timing before the procedure was ok before everything went haywire. Maybe, you have read EME's instructions. If you have, you can take 'em or leave 'em. That's free will! If you have not, you should so you can take 'em or leave 'em.
 

Timing is governed by the position of the crankshaft. The position of the crankshaft is signaled to the ICU by the position of the window in the rotor cup during crankshaft rotation relative to the magnets of the Hall effect sensor.

[frankenduck]

Easy peasy. Align the notch on the HES with the arced notch on the engine block.

[daveson]

When replacing a Hall Effect Sensor, if I carefully mark the orientation of the old one, and line up the new one to the same marks, do I have to re-time it?

No. But if it isn't at the factory setting, as with the photo from duck, you want to ignore the original position, and go with the factory setting. Some people deliberately advance the timing for improved fuel economy or more power, at the cost of increased engine temperature, amongst other drawbacks. If the bike has a temperature gauge that's about forty years old, it might give a reading well below the actual temperature, and the engine might pack up.

I serviced a car once that was the same model as mine, the timing was advanced five degrees over stock, apparently without issues, so I did it to mine. I got my car to 570,000km with the original engine, and got better fuel economy after the change, but six weeks later it packed up, a valve guide dropped, so the valve couldn't close. I think it was due to the increased temperature. The car I serviced had a low mileage compared with mine.

[daveson]

Related: is the bike's timing tightly coupled to the sensor itself, or the position of the sensors relative to the bike's rotating, timing disk?

Yep.

[schrocketeer]

Installed the new Hall Sensor from Euromotoelectric (BOIgnSen-K033EDL). Contact cleaner on both sides of the connection, dielectric grease. Now it won't start enough to stay running.
It will bark for half a second, then the starter just grinds. If I hold the Starter button down with my left hand, and run the throttle from full, to partial, it act like it wants to start, but won't stay running if I let off the Starter. Disconnected the fuel rail return line, to make sure the system was pressurized and no junk.

The reason I installed the new HES, was that it was hard to start when warm, and would not accelerate smoothly. Understand it's Fuel Injected, but it responded like junk in the carb that needed blown out.

1986 K100RT, 53k miles, less than 300 miles on NAPA fuel filter. 91 octane, ethanol free gas, averaging around 40mpg.

For reference, previously had a '85 K100RT I put 25k miles on.

[Laitch]

It's okay for you to loosen the two holding screws of the sensor mounting plate and rotate the plate not more than 1 or 2 BCH units in either direction to see if that makes any difference in starting and idling.

[schrocketeer]

Okay thanks. I'll play with advancing or retarding a bit.
Would you please tell me what a BCH unit is?

[frankenduck]

Some people deliberately advance the timing for improved fuel economy or more power, at the cost of increased engine temperature

Please explain how changing the timing impacts the temperature at which the radiator thermostat opens.

Also, the spark plugs fire the same number of times and cause combustion regardless how far advanced or retarded the timing is. Why would advanced timing generate more heat?

[Laitch]

Would you please tell me what a BCH unit is?

It's a hair's width of a certain caliber. 

If moving it slightly one way or another doesn't improve things, maybe you could summarize what other elements you've may have explored that could cause these symptoms such as:

• Throttle body manifolds or the z-pipe crankcase breather containing cracks that open when the parts are heated.
• A dirty ignition control unit plug pins and their sockets.
• Clogged injectors.
• Failing or loose interior fuel tank hoses.
• A failing ICU.
• Coils and secondary ignition wires.

[Laitch]

Please explain how changing the timing impacts the temperature at which the radiator thermostat opens.

Also, the spark plugs fire the same number of times and cause combustion regardless how far advanced or retarded the timing is. Why would advanced timing generate more heat?

These guys seem to believe the state of timing makes a difference in heat generation but we really don't know who they are, do we? They could be adolescents churning out websites for fun that are financed by Temu sales.
 

[daveson]

Please explain how changing the timing impacts the temperature at which the radiator thermostat opens.

Also, the spark plugs fire the same number of times and cause combustion regardless how far advanced or retarded the timing is. Why would advanced timing generate more heat?

I think I agree with what I think you're saying, that there's not much of a relationship between the timing and the thermostat. I was thinking that the earlier the combustion happens before top dead centre, the more it fights against the crankshaft rotation. This would make the engine run hotter.

In the example I mentioned I think the temperature gauge wasn't accurate. I got a good improvement in fuel economy (back to where it used to be) and the car was on its last legs, so I thought, I don't care if it only lasts a year, the fuel savings would be more than what the car is worth. But it only lasted six weeks, so then I thought, well that was one more silly idea I've tried. Another modification I did on that car was to install a bypass oil filter. I only changed the oil and original filter at 50,000km intervals. It did about 300,000km like that, and it clocked up over 570,000km.