Won't start after new timing case.

Status
Not open for further replies.

reidpik

Joined
Apr 29, 2007
Messages
6
Howdy. I just installed a new timing case and now my 1969 750 fastback won't start. Iv'e tried every possible combination of timing mark alighnment using both of the timing marks on the rotor( at 31 degrees BTDC) as recomended with my Boyer ignition and all combinations of magnetic rotor and stator plate settings. Any ideas?
The two timing-cover wires and teminals are connected correctly and the insulation around the wires is good.
The battery is fully charged.
New plugs installed.
It was running perfect last week until I replaced my timing cover, which includes removing the boyer timing system. Replacing it is very straightforward following the instuctions. I am now frustated and my leg, foot, and hand (from working the kick-start lever whilst reading the timing marks) ache. Any help would be appreciated. Cheers.
 
Easier to kick with the plugs out, too.

If the plugs spark, you know you've got the timing wrong, somehow. As I understand it, plugs should spark whenever the rotor and pickup plate line up, regardless of timing. If they spark, you can check for TDC while you've got the plugs out.

If the plugs don't spark, you've got a bad connection.
 
Just to back up what BillT is saying, It might be worth confirming that your timing marks actually correspond to the correct crank position - this can be checked with the plugs out.
I've known of different alternator rotors having different marks on them :roll:
 
Also check you are using the correct timing hole on the Boyer Stator, one is for clockwise and the other is for anticlockwise.
 
Thanks guys. I will check for spark at the plugs. I assumed there would still be a spark as I only removed and replaced the Boyer timing gear from behind the timing cover. Also, one cylinder back-fired as the ignition was on and I was fiddling with the Stator plate, indicating plug spark. I never touched the timing chain at all. I've just ordered a Tri-spark system as I think somehow I buggered up the Boyer stator plate circuits and coils with too many greasy fingerprints... even though I wiped the works with WD-40. (Here's a tidbit... WD-40 means Water Displacement, 40 is the 40th formula the guy was happy with.) Cheers.
 
The tri-spark sounds great.
I wish I had got one instead of my Boyer.
You won't need the black box now, as it is all built in to the rotor stator unit, I believe.
They also claim to have an led type setup which allows for really easy setup, rather than trying to strobe a vibrating Norton at 5000 rpm!! What a pantomime that was.

I agree with the others. Check for a spark. Then Check your static timing is good. If you look at the Boyer stator plate there is a hole at about quarter to the hour on the plate. If you have the crank setup at 31 dbtdc looking at the alternator side through the inspection cover, the screw in the rotor should be plumb lined up with the hole in the stator.

Stu.
 
If you have been fiddling with it for a bit start with new plugs, or sand blast the ones you have. I have one of those cheap Harbor Freight plug cleaners I use for tuning. You can have plugs work poorly with little visble evidence.
I'd guess you have mucked up your timeing and properly fitting the Tri Spark should help. With the big coils I'm running and the Tri Spark a plug test looks like arc welding.
 
bigstu said:
You won't need the black box now, as it is all built in to the rotor stator unit, I believe.
Click to expand...
----------------------------------------------
That's interesting bigstu, when I first bought my 850 in around 1975 it had an early Boyer system on it which also had the electronics contained in the stator in the timing cover. They had a problem with these packing up when they got hot, that was why they re-designed them and put the electronics seperate, hope the tri-spark doesn't go the same way!
 
daveparry said:
You won't need the black box now, as it is all built in to the rotor stator unit, I believe.
----------------------------------------------
That's interesting bigstu, when I first bought my 850 in around 1975 it had an early Boyer system on it which also had the electronics contained in the stator in the timing cover. They had a problem with these packing up when they got hot, that was why they re-designed them and put the electronics seperate, hope the tri-spark doesn't go the same way!
Click to expand...



This subject has been discussed previously (May '08): post19877.html#p19877

-and this is what Steve Kelly (of Tri-Spark) said at that time:


Steve Kelly said:
I hear your concerns about heat.

In an effort to minimise the chance of a problem, we have sourced all the best temperature rated parts available and potted the whole lot in epoxy under the black cap. The rating of all the parts is well above the temperature that the timing case reaches in our testing.

I have personally road tested a number of these systems in the tiger 750 since January and have found no cause for concern thus far.

Steve
Click to expand...
 
Who's got some time on a Tri-Spark ? Looks as it's the way to go. I'm certain it's an improvement over the Boyer.
 
JimC said:
Who's got some time on a Tri-Spark ? Looks as it's the way to go.
Click to expand...

I've got three Tri-Sparks on the go at the moment, two of them are the original box type Tri-Spark sequential firing electronic ignitions, one of which is fitted on my Triumph Trident T160 (replaced a fully functioning RITA) and the other on my T140V Bonneville (replaced a fully functioning Boyer Micro MkIII), and the boxless Classic Twin wasted spark system I fitted to my Commando 850 MkIII earlier this year (also replacing a fully functioning Boyer Micro MkIII), and all are currently performing very well indeed with starting, and idling certainly better than the Boyers or RITA, although I've never experience any low voltage kickback or reliability problems with Boyers over many years of use, apart from one of the Commando's Boyer pickup wire joints failed, which as I'm sure, most of us know is a fairly common problem, and is easily fixed.
 
Thanks guys, and Cookie the arc welding thing cracked me up. One more question... My rotor (Lucas, I think) has 2 timing marks 180 degrees apart. Which one would determine 31 dgrees BTDC for the Boyer system I've got? If I don't get a spark (or fireing) would I just use the other one? Is this the best way to sort this out? Many Cheers.
 
reidpik said:
One more question... My rotor (Lucas, I think) has 2 timing marks 180 degrees apart. Which one would determine 31 dgrees BTDC for the Boyer system I've got? If I don't get a spark (or fireing) would I just use the other one? Is this the best way to sort this out?
Click to expand...


The correct mark to use would be the one that lines up with the timing scale when the pistons are at the top of their stroke (approaching TDC).
 
L.A.B. said:
reidpik said:
One more question... My rotor (Lucas, I think) has 2 timing marks 180 degrees apart. Which one would determine 31 dgrees BTDC for the Boyer system I've got? If I don't get a spark (or fireing) would I just use the other one? Is this the best way to sort this out?
Click to expand...


The correct mark to use would be the one that lines up with the timing scale when the pistons are at the top of their stroke (approaching TDC).
Click to expand...
A thin dowel with the added safety feature of a standard mains electric grommet pushed over it to stop it dropping into the bore thus requiring a somewhat embarrassing cylinder head removal.....can show when the pistons are approaching TDC.. :D
 
Status
Not open for further replies.
Back
Top