Timing and carb set up

[Ian 14 G2]

I have new points and a new carb fitted to the bike and have tried setting the timing by the book with no luck, doing it this way it seems to be quite advanced so I tured the the piston right back then brought it up to a 1/4 before top dead centre and it did improve things ( no kick back ) but still would not tick over, I am now moving the timing a little at a time with two securing screws on the back plate not fully tight and things seem to be imprving little by little but I am wondering when I will know when it is correct. The bike starts 1st or 2nd kick but runs erratically but I know untill I sort the timing I wont be able to set up the carb correctly, so I am hoping for some help from you members who have years of knowledge and experience as I'm

[SPRIDDLER]

Basics first Ian, so that we don't go down blind alleys....

Did you set the timing with the ignition fully advanced?
Is the points gap correct? (When it's larger than specified it reduces the 'points closed' period to the extent that the coil will not receive voltage for long enough for it to produce a decent spark when the points open).
Have you cleaned any traces of protective coating off the new points? (Petrol on a non-fluffy cloth).
Are the A/R bobweight springs fitted o.k?
Have you tried another spark plug? (Long shot, but it could a failing plug).
I assume you must have correctly timed it on the compression stroke not the zorst stroke or it wouldn't run at all.

For the new carb (Monobloc?). Presumably the correct jets have been fitted.

At tickover until about 1/2 throttle the engine is being fed fuel only from the Pilot jet (and slide cutaway but we can ignore that for now) therefore the Pilot jet is the only critical adjustment needed at present. Start by closing the Pilot jet by gently screwing it in until you feel it stop (no forcing or you will damage the tapered pilot jet tip and/or jet seat), then open (unscrew) the jet one and a half turns. That'll be fine for now.
You have of course screwed the throttle stop screw in so that it does actually lift the slide from its rest position to establish a fast tickover haven't you?

(Wish I was riding or fettling instead of bored stiff at my son's waiting for the Sky engineer ).

[Rangy65]

I think you need to wedge the bob weights open whilst setting these up at fully advanced - I got fed up so fitted a Boyer electronic ignition no problems now.


Have fun

Steve

[Ozmadman]

How are you measuring the 1/4" BTDC ? I find the simple (find TDC and keeping the rod as upright as possible, make a mark a piece of rod in line with the spark plug thread edge, then accurately measure 1/4" ABOVE the first mark and make another mark) works best. Find TDC again (on the compression stroke, both valves closed) and then, in gear, move the rear wheel backward and then forwards again to bring the piston up to where the TOP MARK is in line with the spark plug thread... This will be 1/4" BTDC.. Wedge the ADV/RTD unit fully open and adjust the points back plate so the points (I set mine at 0.014") are just opening (I use a multimeter to determine the exact opening point, it's more accurate than the cigarette paper method) that's it... tighten everything up and recheck... It's easy using a meter as the reading will change as soon as you wedge the ADV/RTD unit open

[SPRIDDLER]

I find the simple (find TDC and keeping the rod as upright as possible, make a mark a piece of rod in line with the spark plug thread edge, then accurately measure 1/4" ABOVE the first mark and make another mark) works best.

Here's my timing probe (a piece of coat hanger) if it helps explain , marked for 7/16" and 1/2" BTDC.....

[Ozmadman]

Much like mine, the cranked top is important to prevent it dropping into the bore!!

[Janet]

I use a thing like this.

[Ian 14 G2]

I am taking note of all the advice I am being given , I have my TDC tool and my multi meter and I'm reading up on the subject as much as I can so I'm going to have a few days away from the bike and set aside one day next week to start with a clear head and will post how I get on.

[Janet]

When I got my bike I had some problems with starting and running it, even though the previous owner ( and his mates ) said it always fired up first time. Having obtained a manual (neither of the previous owners had one ) I discovered that the adv/ret unit was about 90° out. Experts eh? It responded better when I played about with it using the knowledge I then had but I found that lining up the adv/ret unit properly was the hard part of the procedure. I'd put it on according to the drawing and then it would move. Finally, after several days, when I'd got it to stay where I'd put it, the 'fine tuning' was relatively easy. I even did it all again so I could change the leaky gasket behind the ignition housing. Whoever said there is no oil in the rhs cover had never seen my bike.

Sometimes I wish I knew what I was doing but that would take half the fun away.

[Ozmadman]

lining up the adv/ret unit properly was the hard part of the procedure. I'd put it on according to the drawing and then it would move. Finally, after several days, when I'd got it to stay where I'd put it, the 'fine tuning' was relatively easy.

Must admit, if you decide to remove the adv/rtd unit it is a bit of a bugger getting it back in the right place, just trial and error and patience is the order of the day..