[TEXGWNUBE]

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Working on a 1100 we just purchased not running. Compression is great - mechanically the timing is perfect (cams and crank are perfect). No fire other than occasional backfire. Put a timing light on the #1 cylinder and the spark is occuring about 30 degrees before TDC. I moved the light to the other 3 plug wires to make sure the wiring wasn't wrong - but none of them lined up so the wiring looks fine.



I ohmed out all the electrical - even the pulse generator. Everything is working great - just firing at the wrong time. I tried manually advancing the vacuum advance with a vacuum pump - but it can't make up 30 degrees.



Has anyone had the pulse generator go bad in this fashion? Is it possible to install it in the wrong position on the motor?

 

[wda-83wing]

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i once had the same thing happen to me . on a parts replacement. i replaced a vacum advance assy. complete with the cdi pluse generator coils . anyway----i could not get it to run , just back fire.messed with it for a couple of days. had good spark at the pluges. everything went as it should have with the part replacement , BUT some where or some time or another , the wirer connection at the front of the battery box had the connections switched . in other words---it was fireing 180 out of time. i switched them around and it scared the s**t out of me when it started and idled like was surrpose to. i`ll go back through my posts and find where i posted the cure and what i did.

 

[wda-83wing]

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i dont find it in my old posts , any way --use a timing lite on # 1 pluge lead and see if it flashes on the T1 or the T2 mark on the fly wheel. that will tell you if they have been changed or if they are ok. hope this bit of maddness helps some.
ps--- it should flash on the T1 mark with it hooked to #1 plug lead wire.

 

[Hatchetman]

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It sounds like crossed wires to me. If the cam timing was 30 degrees out you would be smashing valves & pistons. if it isnt plug wires on the wrong plugs, it would be at the coils or what wda was talking about. Sounds like the P.O. might have mixed something up.

 

[TEXGWNUBE]

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Thanks for the tips guys. I was thinking about checking the T1 mark with the light but last time I ran it without the plug I had oil everywhere.



Maybe I'm checking the timing wrong? I had the mark on the RH CAM which should be lined up with the mark in the center of the valve cover - this mark along with T1 on the flywheel should be lined up for TDC. So,by having the timing light on #1 and looking at the RH CAM my TDC mark should be lined up with the mark -- currently its 30 degrees below the mark.



I thought about wires being flipped so I put my timing light on all 4 plug wires while looking at the timing mark - figuring that if it was some mixed up wires 1 out of the 4 would hit at the right time - but that didn't happen.



Has anyone had the pulse generator off? Is there a way to mount it wrong which would cause the timing to be off on all cylinders?

 

[jackjohn]

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If you have had the pulse generator off, then it is possible the dowell pin was left out during reassembly. If this is the case, your spark can be off considerably. This is the only thing I have ever seen go wrong with the PG's. See page 15-8 in the Honda repair manual.

 

[wda-83wing]

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yep---if the pin is left out. that will cause the timeing to move . no need to have engine running to check the timeing. just have the pluges connected to there connectors and laying on the heads. a lot less strain on the battery. and you dont get sprayed with oil.

 

[DaveO430]

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TEXGWNUBE wrote:

Maybe I'm checking the timing wrong? I had the mark on the RH CAM which should be lined up with the mark in the center of the valve cover - this mark along with T1 on the flywheel should be lined up for TDC. So,by having the timing light on #1 and looking at the RH CAM my TDC mark should be lined up with the mark -- currently its 30 degrees below the mark.

If you are looking at the cam pulley with the timing light the actual ignition timing is 2X that amount off. So if it's 30 deg. off on the cam it's 60 deg. off on the crank.
I think the other guys are right about the PGs being out of place.

 

[TEXGWNUBE]

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Looks like we will be pulling the rear wheel and checking it out. I'll let you know how it turns out.

 

[TEXGWNUBE]

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Just a quick update - we tore into the back of the motor and found the shaft that extends out the casing for the pulse generator was sheared. We have to pull the motor to replace the shaft. Curious as to what caused this. There is a bearing in the casing that is pretty rough turning but not too bad.



Any thoughts?

 

[TEXGWNUBE]

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anyone have a "mechanical advancer driveshaft" this is the shaft that attaches to the rear of the crank - you have to pull the rear engine cover to get it out.

 

[JBz]

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I dont think you have to pull the engine or the rear coverto remove the shaft but you do to replace the drive bearing. you might have to split the cases to replace that bearing .If its rough that might be why it sheared. Might want to check your oil strainer and see how it looks. JB

 

[wda-83wing]

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TEXGWNUBE wrote:

Just a quick update - we tore into the back of the motor and found the shaft that extends out the casing for the pulse generator was sheared. We have to pull the motor to replace the shaft. Curious as to what caused this. There is a bearing in the casing that is pretty rough turning but not too bad.



Any thoughts?

it is possi9ble that someone tried to turn the engine over useing the 10mm bolt head at the end of the shaft ? causeing the pin to shear . if the bearing is bad--relace it ! ! as this could cause the air gap on the pluse coils to be out of specs . the air gap spec for the coils is on page 10-21 of the honda manual , 0.50-0.70 mm , thats 0.020-0.028 in. . hope this is of some help.

 

[TEXGWNUBE]

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Just letting everyone know what was found. There is a pin that is pressed in at the end of the PG shaft - it turns on the crank. This pin was sheared. We replaced the pin and it fired right up! Now we are concerned about all the clutch powder found in the bottom of the casing. Does anyone have any tips or stories about replacing the clutch pack?



Thanks again for everyone's help!

 

[sandiegobrass]

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TEXGWNUBE wrote:

.... Now we are concerned about all the clutch powder found in the bottom of the casing. Does anyone have any tips or stories about replacing the clutch pack?...

Wouldn't worry about it yet unless it is not working.... the clutch powder that is not filtered out in the oil filter stays in suspension.... BUT.. when the bike sits for extended periods(months or even years).. this powder settles out in alayer on the bottom of the case...

Change the oil.. flush if you want to, larger chunks might get slowed down at the screen (or plug it) but the full flow oil filter will prevenet it from going through the engine..

[Incidently this is a good reason to change your oil before storage.. not after]