Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board 1968 T120 Timing Marks

Question for the wise and the worldly here.

My 1968 T120 has a timing mark on the rotor. This is cast (or cut) into the rotor, so not a DIY mark that someone has added.

However, I cannot see any aligning mark on the primary case or the stator.

At TDC the rotor mark aligns with a screw hole (about 5 o'clock) but this may be coincidence. I have 3 screw holes, so not like some of the chaincases that I have seen with a timing hole as well.

I would have thought to be any use there would need to be a mark somewhere at 38BTDC.

Is this a mix of components or am I missing something.

It's not a major issue as I can add my own 38BTDC but it's a bit fiddly to do accurately.

Secondary (possibly stupid) question - I have a Boyer MKIII EI. It has clockwise and anti-clockwise timing holes. I assume this refers to the exhaust camshaft rotation (as viewed from the timing inspection hole).

Thanks all.

https://www.baxtercycle.com/product/60-2014/
Had to use this gadget to time my '68 TR6R.
Hope this helps.

On page B28G of the 1963 to 1970 Triumph Shop manual there is a drawing of a Timing plate, Triumph part number D2014 that screws into the timing cover holes and provides the corresponding timing marks. Hopefully they are still available. I got mine a long time ago.

You are missing a manual by the sound of it:

http://www.classicbike.biz/Triumph/Repair/1970s/70-Triumph-Repair-Manual-63-70.pdf
Section B31.




Yes Edit: Assuming you mean viewed looking into the points cavity on the timing side and not somewhere else?: http://www.boyerbransden.com/pdf/KIT00052.pdf

+1

http://www.britcycle.com/Products/Tools1/222601825.jpg

timing plate D2014 shown in this pdf
http://www.britcycle.com/manuals/222602014Inst.pdf

The pointer on the primary cover wasn;t added until 1969.

If you find a '69 to-72 timing cover you will have it, and won't have to fiddle around with the 1968 timing accessory tool.

With EI this timing plate is a one time use. I check my timing every few years.

Hi Peter, Until you find the timing pointer tool for '68, (60-2014) you could use the TDC tool in the 38b slot in flywheel. Mark the case with marking pen or a notch. Sight it straight on to set timing. Generally speaking a '68 will need the early fine thread tool. Look at your TDC hole plug & match the threads.

Later primary cover in good shape is getting hard to find here. Repro timing covers have many changes that don't make them a desirable option in my mind.

If... you are really skilled, you could drill & tap flange in your cover for counter sink head screw & make a pointer. To retrofit the original press fit pointer takes a milling machine & end mill cutter to recess the flange. If you are super skilled you can use end mill in drill press, but need to make a jig to hold cover.

Lots of ways to ruin cover during modification. Try to find the tool. Even with EI if you keep bike you will surely use it again (and again in most cases).

If you are skilled the tool can be made at home, but you still need TDC tool to locate the crank at 38b to mark tool.
Don

10.5mm btdc is about right/38 degs on a 650 trumpet. (10.8 is more exact)
Use a vernier then paint a mark on your alternator and the cover.or use a bit of wire.

Thank you all for the flurry of answers arriving whilst I slept! :-)

I do have the manual, but it does show both the tool and a marked chain case as options.

It doesn't look like the D2014 tool is available in the UK. Search of my usual parts providers came up blank. If any of the UK guys on this forum know of anywhere that has them please let me know.


I don't have a flywheel plunger tool. I have had a look at the thread on the crankcase and it is a course thread and the plug is 5/8 AF (see picture below). Seems that only the D1859 tool is available in the UK and this is specified fro 1969 onwards (although it does have a UNC thread). Does that sound like the right tool?

I don't fancy messing about with the chain case, but I do have a 3d Printer. I think I might have a go at making something along the lines of the D2014 tool..

Thanks again
Peter

Thank you L.A.B.

That's a nice option with both BSF & UNC.

I took a gamble and ordered the UNC version from Feked. Hoping it's right. If not then I'll return it and get this one.

Shame they don't sell the timing plate too.

Cheers
Peter

If the plug thread is 1/2" x 13 TPI then it will be.

If it's 1/2" x 16 TPI (BSF) then it won't.

Edit: Looks more like UNC in your pic.

So, I had a go at printing a Timing Plate tool.

I haven't used the printer for a while so it could probably do with a bit of fine tuning but the result seems to be ok.

I have 38 degrees from the centre of the nearest screw hole to the timing mark.

Couple of other jobs to do before I get the bike off the ramp and do the timing but I'll let you know how I fare.

So now I am totally perplexed!

I received my flywheel plunger tool today and checked my home made timing plate and it is pretty much bang on. Maybe 37BTDC but I can work with that when I come to strobe it.

However, I am checking the Boyer stator plate and it will only line up with the Anitclockwise timing hole. The camshaft definitely turns clockwise.
There is no way that the magnetic rotor has moved on the camshaft as it is well and truly down on it's taper (not sure how I am going to move it if I need to!)

The bike was running previously and I have not touched the camshaft timing. All I am doing is checking the ignition timing.

Is it possible the bike would have run with the Boyer lined up on the anticlockwise timing hole?

Starting to think I'm going mad. Can anyone see what I am doing wrong?

(Pictures are with the flywheel locked at 38BTDC)

Thanks
Peter

The rotor is threaded 5/16" UNF so screw a long-ish 5/16" UNF bolt into the rotor then if you tap the bolt head with a hammer in different directions (up, down, left, right) should free the rotor.

Hi Peter
Are you sure the rotor is fully seating in taper and not hitting the pin inside the camshaft it can appear to be tight but loosen off with vibration i'm in process of trying to time a Pazon iv'e just fitted.
Iv'e set everything to instructions fire her up it starts first kick revs freely idles just but after 2-3mins starts running erratic and backfires
Tomorrow i'm going to remove the rotor see if there's any witness marks on the taper edge sure somethings moving.

Are there 2 grooves in your flywheel ?? if so Are you sure the timing plunger is in the first groove when turning the crank clockwise for BTDC

Dave

Thanks L.A.B. I’ll have to try to find a suitable bolt.

Dave Lid - the rotor is definitely on the camshaft firmly. Won’t move at all.

I have found two grooves in the fly wheel. One at TDC, as verified by checking the right hand piston position. And 1 at 38deg before TDC. I am checking the Boyer at 38BTDC.

I am really struggling to see how the bike ran if it was timed to the wrong hole, hence why I am concerned I am missing something. I’ll have another run through all the steps tomorrow before I pull the rotor off and reposition.

Thanks
Peter

How was the Boyer pickup plate positioned before you removed it?

It looks like someone has elongated the slots.

With elongated slots and the pillar bolts in the second set of holes, it looks as if there could be enough plate adjustment for the engine to run.

@L.A.B. - I can't say for sure (didn't take a picture) but I think the stator board was as far clockwise as it could go on the slots. And yes, it does look like the slots have been elongated (see photo). But even in this position the clockwise timing hole doesn't line up, but it is as close as it can get with the rotor where it is. In the photo you can just see the silver magnet screw is about midway between the two holes

Bit worrying that there is an "R" with an arrow facing anticlockwise scratched on to the stator board! (see photo)

If no one thinks I am completely missing something fundamental here then I will get the rotor off and realign it with the clockwise hole and see how things go from there.

Thanks
Peter

You could try filing the slots some more until it does line up but joking aside I'd guess the rotor was tightened down in the wrong position and whoever did it, didn't know how to remove the rotor so filed out the slots far enough for the engine to start.




I doubt it's anything to worry about. Perhaps the pickup was fitted to a BSA or Norton Commando at one time and marked for anticlockwise rotation as that would have been correct, but whatever the reason for the 'R' marking, the rotor needs to be set for clockwise rotation.

You do need to strobe check the ignition afterwards as the paint marks are only there to get the ignition timing close enough to start the engine.

That thing was obviously butchered by someone to make it work. Time to buy a new, correct timing plate.

Rotor is off now. Just happened to have a spare 1m length of 5/16 UNF threaded rod kicking about that I bought to mount a Triumph Spitfire (car) engine on an engine stand. That made light work of "encouraging" the rotor off!

I've ordered a new stator plate from Boyer (£38 - ouch!). The existing one will probably be fine but thought I'd better get a replacement.

Really need to get to work on the electrics generally. I don't like the cheap and nasty connectors that have been used in a few places (including fitting the Boyer). May be a winter project to re do the wiring loom.

yeah, the rotor is positioned incorrectly,...The existing plate would be fine with the rotor relocated...But now you have a spare....