Ignition is 90 degrees out somehow

[Broder]

Hi Guys, I need some help here in Thailand. I have replaced my cam timing chain and somehow got something wrong. I joined the new chain onto the old and wound the new chain on carefully. Once done I made sure that the cam was lined up correctly with the shaft machined slot at 12 o'clock while the pistons were at TDC. I was worried that I may be a tooth off but it looked correct at the time. I riveted the new link on just so and checked again to be sure.
Now I am running a Boyer ignition and PMA unit, all worked well together before I replaced the chain. Engine back in the bike and she won't fire with the timing set at 15 degrees advanced as per the Boyer Instructions. I played and adjusted with it all day and finally got it to start right up with the timing set at about 110 degrees BTDC or about 95 degrees too far advanced.The timing mark is at 9 o'clock position now instead of near the bottom at 6 o'clock as it should be. What would cause this? Did I somehow get the camshaft in upside down?
Thanks in advance for your help. No pun intended.

 

[Brian902]

This might help to make sure your cam is correct first;

http://www.650motorcycles.com/CamTiming.html

Some pictures of the advance rod installation;
https://www.google.ca/search?q=xs65...cQ-HswGYM:&usg=__ORzDFYt2eHW_RV0DytznK8PpoH0=

Could be either or both are off, so check carefully.

Cam timing first and advance rod second, not that it really matters, just more logical order, either can be off their marks.
.

 

[Broder]

Thanks for your input Brian. I thought the cam was installed correctly. It looked right at the time.The advance rod position is adjustable on Boyer ignition, that was correct as well .
My main question is why the timing is off 90 degrees. I suppose the only answer is that the cam alignment is off by one or two teeth, Yet the valves open as and when they should. I can see the piston and intake and exhaust valves thru the spark plug hole.
I would hate to pull the engine out if I don't have to and what if I open the top end and find the cam is aligned correctly?
Stumped in Songkhla.

 

[peanut]

Welcome to the forum Broder!
This is an odd problem to be sure.


If both the pistons are at TDC
(don't rely on the marks on the Rotor and Stator ,check in the spark plug holes using a pencil or screwdriver)
and the slot on the camshaft is vertical (either at 12am or 6pm ) then there is only one way that I can see your cam chain being 90 degrees out and that is if your camshaft sprocket has slipped or has been replaced and pressed on the camshaft 90 degrees out.

With your engine at TDC... check that all your valves are fully closed using a feeler guage.
Check that the Boyer is installed the correct way round

 

[Brian902]

But did you read that second part of the first link and actually check for cam alignment?

It's pretty straight forward procedure and the cam timing is either right or wrong.

Once you know that, it means the engine does not need to come apart to fix that part.

The rest can be done externally so to speak, without removing engine or head and other things, so much easier.

Then start checking the advance unit and point issues.

One step at a time.

Good Luck.

 

[Broder]

Brian, I took your advice and read the sticky closely. I pulled the cover off and lined the crank at TDC as suggested and viewed the pin hole at the top of the cam. The cam is misaligned by at least one sprocket tooth so now I know what is wrong, I assembled it incorrectly.
Peanut is also correct but in my case one sprocket tooth put the timing out about 110 degrees from TDC. It is a wonder the engine started up and ran at all, ran pretty good too.Down to the pub and back.
I will have the engine on my work bench by noon and will pull the cylinder head cover, I must find a way to remove one of the cam bearings so as to get the chain slack enough to realign the cam. Any thoughts on that procedure? If the bearings are stuck on the end I will need a new master link. Prolly have to renew the oil seals too.
Thanks

 

[Brian902]

Cam bearings should come off with some light tapping. Just a snug fit. Remove all 4 bearings is the easiest.

When re-installing, make sure the distance at the end of the cam bearings and the housing they sit in is equal. In other words the whole assembly bearings and cam are centered in the head.

Other wise end caps will not fit properly and cam seal leakage occurs.

So push the bearings in tight on the cam ends and then just check for equal distance between the outer bearing and it's bearing surface.

Good Luck.

 

[retiredgentleman]

This topic seems to come up all too often. The alinement of the camshaft and the crankshaft is really very simple. Many people only refer to the TDC mark for the crankshaft, and the left side camshaft slot at 12:00 for the camshaft.

If anyone takes the time to read the Yamaha Service Manual................guess what, there is a third reference mark. On the right side of the camshaft gear, there is a punch mark, that must aline exactly with the top surface of the head.

With those 3 marks, its impossible to mis-aline the crank and cam.

 

[Broder]

This engine is driving me nuts! I removed the motor, put it on the bench, removed the valve cover and the cam bearings. This gave me enough slack in the cam chain to shift the sprocket by one tooth. Now the camshaft marking is aligned vertical with the pistons at exactly TDC. End of problem or so I thought.
Engine back together, back into the frame again, bolt it down, bits and pieces back on.
Go to fire it up- guess what? Will not start. No way.
Work on it,play with it, try this and that. Finally got it to start with the timing advanced about 50 degrees this time. Not easy to start but once running idles well. Purrs like a kitten.
I cannot figure out what I got wrong. I re-checked TDC ( I can see the piston thru the spark plug hole ) and the cam alignment hole on the right hand side...fine.Vertical but the cam must still off or it would fire up at 15 degrees BTDC.
At 50 degrees BTDC the exhaust valve is still open. How can the engine even start?
Question, now what do I do?

 

[peanut]

My guess is that you have not set the Boyer up right or the Boyer is faulty.
This has to be a really simple problem

The engine fires and runs and idles fine with the ignition at 110 degrees so there is nothing wrong with the engine carbs electrics or ignition system . It has to be the Boyer reading the camshaft position wrongly and giving the spark at the wrong crankshaft position relative to TDC

Lets see a good picture of
1.the boyer with the pistons at exactly 38 degrees before TDC with the white mark showing through the hole
2. the stator showing the rotor mark aligned with the full advance mark BTDC

 

[MartinNC]

I've recently fitted a boyer, the white mark should be showing when engine is at full advance, 38 degrees BTDC

 

[peanut]

yes thank you Martin I'll amend my post

. I couldn't remember the degrees and just assumed that the Broder had got it right.
This is why I asked him for some pictures so that we can see where he has set it.

I added a video at the beginning of the thread showing how to install a Boyers ignition system and unfortunately I also used the wrong advance mark initially and I although I subsequently added a correction on youtube it may not be clear on the video so it could well be my fault.

I have taken the liberty of adding an image of 5twins I found on the net as I cannot find one of my own

 

[Broder]

I have finally found the problem, I think. The Boyer ignition is faulty. It seems that the magnets trigger the coil only when they are in very close proximity. That's why the engine runs well although it looks like the timing is set at 90 degrees BTDC.
I have emailed Boyer several times in the last 5 days. No response at all. Tried to call Boyer on the phone, guess what? No answer. I am a bit cheesed off. Should have bought a PAMCO.
Not sure what to do next. Where to get spare parts? I don't dare run my bike on the street in this condition. I might make it worse. It has taken me 3 years to build this Tracker, now I want to use it.
Any ideas?

 

[MartinNC]

One thing you want to consider is that Boyer's are very volt sensitive, drop below 10v ands you are in trouble. I think that when voltage drops the ignition advances.

Do you have your charging system and battery in good shape?

 

[peanut]

what many owners do not appreciate is how easy it is to damage any electronic ignition and advance module if you try to start the bike with one or both HT leads loose and unable to ground a spark

 

[veedub1955]

This is EXACTLY what I am experiencing! Hence doing a search and finding this post. Have you replaced the boyer module yet? And if so has it cured the problem?

 

[Brian902]

Perhaps this will help;

http://www.britcycle.com/Manuals/BoyerTroubleShooting.htm

and or;

http://www.tioc.org/boyer/boyertestnewweb.htm

not Yamaha but Triumph and BSA have been using these for years.

Second site has lots of good basic info!

And of course one more for good luck;

https://www.oldbritts.com/boyer_testing.html

Good luck!

 

[veedub1955]

Thanks Brian, the second link had the answer!!

Fixed it Broder, its the trigger plate wires the wrong way round. I foolishly ignored to check thinking that it wouldnt make a difference as there seems to be no difference when looking at the plate, but there obviously is. Fired up straight away on the correct timing marks when swapped round. I owe you a beer Brian cheers!

 

[peanut]

excellent result ..nice one Brian ! I'v bookmarked the Boyer guide by Healey

I seem to recall another thread recently about a 90/180 out of phase timing issue and they had a Boyer Micro Digital . It never ocured to me to ask if the Boyer leads were the right way round

 

[veedub1955]

Daft isnt it, its just a pair of magnets going past 2 coils exactly the same distance apart, how does it know its going past the right pickup coil?? Hence not checking that. Just been out for first proper blast round the block for the 1st time since I bought it as a project 5 years ago, its everything I hoped it would be and more