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How to time my FXR 1989 with a strobe light ?

Started by 1340evo, October 26, 2019, 12:20:00 PM

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1340evo

October 26, 2019, 12:20:00 PM Last Edit: October 26, 2019, 12:38:40 PM by 1340evo
Hi Guy's.. just want to check if I'm right before getting started tomorrow. I have a plastic plug, a strobe with a dial knob and I've been looking at my flywheel and painting the scribed lines and dot so I can see them...

My bike has VOSE but I think you just leave that connected. I have a dot before TDC and a large scribed line at TDC... so I think I can do it 2 ways.
With the strobe set to 35 deg, the TDC line should appear in the window at 2000 rpm
With the strobe set to 0 deg, the dot should appear in the window at 2000 rpm

Cant see a lazy 8 at all??

How do I check the VOSE... I think you remove the pipe and the RPM should drop?
What sould the timing be a tickover?.... Thanks

turboprop

The bike being an FXR is irrelevant to the question. The procedure to time an EVO (And nose cone shovel) and check the VOES are the same regardless of the chassis they are installed in.

Timing - The VOES has two wires coming off of it. One goes to ground, the other goes to the ignition module. Ground the wire from the ignition module while you set the timing. Use the mark on the flywheels that indicates top dead center for the front cylinder. Set the dial back on the timing light to whatever you want to set the timing to. The 35 degree factory timing might not be best for every application. Good example is my old 106" evo with 11:1 compression. It was happiest at 28 degrees of full advance. If the ignition module has user selectable curves, it should be set to the most advanced curve while setting the timing. Once the timing is set, reconnect the VOES and set the advance curve to the appropriate setting.

VOES Test - The VOES is checked with a vacuum pump w/gauge and an ohmmeter. It is a normally open SPST vacuum operated switch. Connect the ohmmeter to the leads coming off of the VOES. The polarity is irrelevant fo this test. Apply a vacuum. Make note of the vacuum at the point that the switch closes. Not all VOES switches have the same closing point.
'We' like this' - Said by the one man operation.

1340evo

Hi... many thanks for your reply...so the VOES acts like the weights on a  point unit, opening at a given RPM (or closing in this case) and changing the timing... so yes, ground it as you say so it sees the max advance.
I dodn't have a tacho so will have to guess 2000 rpm...
Can't check the VOES as I don't have a meter, but remember sucking on the thing before and it does switch...

which on for which model? is there a look up table?...

turboprop

Quote from: 1340evo on October 26, 2019, 02:25:58 PM
Hi... many thanks for your reply...so the VOES acts like the weights on a  point unit, opening at a given RPM (or closing in this case) and changing the timing... so yes, ground it as you say so it sees the max advance.
I dodn't have a tacho so will have to guess 2000 rpm...
Can't check the VOES as I don't have a meter, but remember sucking on the thing before and it does switch...

which on for which model? is there a look up table?...

No.

The VOES is a simple open close switch that controls which curve the module is using. The two curves act like the springs in mechanical advance system.

No tach early required. The strobe will show you when the ignition is operating at full advance. Simply increase the rpm until the mark stops moving. That is full advance. You will probably have to make several runs at it until it is set correctly.

Old timer tip. Dont use the timing hole when the engine is running. Instead make a couple marks inside the primary case. One on the sprocket and another to index when the front cylinder is at TDC. This will put less oil on your face.
'We' like this' - Said by the one man operation.

JW113

Especially if you drain the primary first. No oil in the primary for long enough to time the bike is harmless.

VOES: Vacuum Operated Electric Switch. With "high" vacuum (~3" Hg), module is in advance mode. This is for light and moderate throttle, and is to give a little more power and better fuel economy. With "low" vacuum (< 3" Hg), the module retards the timing ~5 degrees to prevent detonation/pinging.

Depending on what you've done to the bike (cam and static compression), the stock VOES setting might not be set so the bike does not ping under heavy load. You can adjust the VOES. Remove the rubbery looking plug from the nose of the VOES, and you'll see a screw head. Turning the screw increases or decreasing the vacuum trip point of the switch. On mine (9.5:1 and very tame cam) I had to adjust to about 4.5" Hg. If you do remove the rubber plug, you have to seal the nose again or you'll have one hell of a vacuum leak. I use dielectric grease and cover the nose with a big vacuum cap.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

Cheers guy's, will have a play tomorrow.... remember now about the VOES and tuning it.. guess mine is std as my engine is std... just want it to run right... no top end.... see where we are.

On the primary you talking the clutch hub?.. can't see my front sprocket?

turboprop

Quote from: 1340evo on October 26, 2019, 03:57:18 PM
Cheers guy's, will have a play tomorrow.... remember now about the VOES and tuning it.. guess mine is std as my engine is std... just want it to run right... no top end.... see where we are.

On the primary you talking the clutch hub?.. can't see my front sprocket?

No.

I was referring to the sprocket on the engine main shaft.
'We' like this' - Said by the one man operation.

thumper 823

........another advantage of primary belt drive.
D Troop 3/5, - C/16 ,162AHC, Mekong delta.
Rising from the Ashes  UHIH

1340evo

I have seen post where the TDC has been marked in the timing cone also... I think by making a viewing hole... but how accurate is that?
bigger the diameter the better :)

jsachs1

TECH PRODUCTS made a bolt on piece called EZ Time, which was a piece of aluim. that bolts to the inner primary next to the alt rotor. On the bracket every .280" equals 5 degrees. Not sure they are still available.
IF NOT:
It's very easy to scribe a (TDC) 0 degree line on the rotor, and a corresponding line on the inner primary. Use a degree wheel and mark the rotor where you want to set your timing at idle and total advance.
Use a timing light, and it won't get any easier than that.
John

thumper 823

This^
That is exactly what I did.
The amazing thing?
Harley actually had the TDC mark at the correct pint in the window!
D Troop 3/5, - C/16 ,162AHC, Mekong delta.
Rising from the Ashes  UHIH

1340evo

Quote from: jsachs1 on October 27, 2019, 03:54:59 PM

It's very easy to scribe a (TDC) 0 degree line on the rotor, and a corresponding line on the inner primary. Use a degree wheel and mark the rotor where you want to set your timing at idle and total advance.
Use a timing light, and it won't get any easier than that.
John

Will have a go at this.. can't think how much of the sprocket I can see through the center panel, but as said, drain it off and use this.. I can dial 35 deg into the strobe so just TDC mark will do :)

Burnout

Due to the uneven firing pulses of a dual fire system your dial back light may not provide expected results.
It will be correct at Zero though.
They don't call me Ironhead Rick just because I'm "hard headed"

1340evo

Good point.. so I do need to work out the 35 deg... I think this is the dot of the flywheel so mark that instead of the TDC mark  :up:

jsachs1

I would mark it out. If you plan on more compression, or other mods, etc. You might find it runs better with less advance.
John

turboprop

Quote from: 1340evo on October 28, 2019, 09:28:46 AM
Good point.. so I do need to work out the 35 deg... I think this is the dot of the flywheel so mark that instead of the TDC mark  :up:

If you have a dial back light, why screw with the 35 degree mark? Use a single mark indicating TDC for the front cylinder and dial whatever advance you want into the light. Simple and very accurate.
'We' like this' - Said by the one man operation.

1340evo

Quote from: turboprop on October 28, 2019, 04:29:38 PM
Quote from: 1340evo on October 28, 2019, 09:28:46 AM
Good point.. so I do need to work out the 35 deg... I think this is the dot of the flywheel so mark that instead of the TDC mark  :up:

If you have a dial back light, why screw with the 35 degree mark? Use a single mark indicating TDC for the front cylinder and dial whatever advance you want into the light. Simple and very accurate.

But, as said above, will the two offset sparks confuse it?.. do they work okay when used like this as they have to calculate when to flash... where as a zero dialed in, it's just a flash when it see's a pulse.. no calculation required.