I have no timing marks anywhere on my 1275.

[jaegzie]

I have a 1275 that runs poorly at best. It starts hard and doesn't have a ton of power.

I have had the timing gear out to get it to where it needs to be, so I'm confident with that. The issue now is where the dizzy needs to be set. Without any marks I try to get it by ear but as soon as I shut it off after I think it's good same thing. Any ideas please let me know.

Is is this where I do the static timing where I turn the distributor until the light goes out?

Thanks.

 

[SD Bugeye]

With the syptoms your discribing me I would check the condition of the dizzy is the plate free?
vac diaphragm not ruptured. Then go after the timing.
Here is a static timming article pretty good https://www.minimania.com/DISTRIBUTOR__Initial_ignition_timing_set_up

 

[Boink]

I didn't have them on my 1275 either... but I added them. The trick, of course, is to get a true bead on Top-Dead-Center of cylinder #1. Thankfully, I had the head off and had a really good gauge; there are other methods too though. Then, added a wire pointer and painted on TDC on the harmonic balancer (added 10 degrees too).

 

[jaegzie]

Thanks for info mark. I was going to do that but didn't want extra marks if I was doing something wrong. Thanks for pics.

Is there an info page with distributor info? I don't know how to check either of the things you mentioned.

 

[Gerard]

View attachment 37697 View attachment 37698View attachment 37699
I didn't have them on my 1275 either... but I added them. The trick, of course, is to get a true bead on Top-Dead-Center of cylinder #1. Thankfully, I had the head off and had a really good gauge; there are other methods too though. Then, added a wire pointer and painted on TDC on the harmonic balancer (added 10 degrees too).

BTW, when using the dial gauge to determine TDC, the gauge should be set up at the center of the piston, not the edge. This is to avoid any error should the piston rock back and forth at all on the wrist pin.

 

[Boink]

Thanks Gerard. Good point. We used the multiple marking method then splitting the difference... which, I think, allows for a pretty accurate determination (even with some lateral piston movement).

 

[dklawson]

I have not had occasion to try this with an A-series since I have always set cam timing with the head off... but do the A-series heads allow the use of a stop-bolt in the plug hole to determine TDC?

Once you have TDC you can make the pointer and mark that Boink did. If you would rather, Jeff at Advanced Distributors makes a timing pointer and tape kit (link below) to allow the addition of timing marks to the front pulley where you can see them.
https://advanceddistributors.mybisi.com/product/1275-midget-sprite-timing-tape-kit

 

[Boink]

Kinda wished I did the timing tape kit myself.

 

[nomad]

I have not had occasion to try this with an A-series since I have always set cam timing with the head off... but do the A-series heads allow the use of a stop-bolt in the plug hole to determine TDC?

Once you have TDC you can make the pointer and mark that Boink did. If you would rather, Jeff at Advanced Distributors makes a timing pointer and tape kit (link below) to allow the addition of timing marks to the front pulley where you can see them.
https://advanceddistributors.mybisi.com/product/1275-midget-sprite-timing-tape-kit

That is what I was going to suggest, Doug. You should be able to put a bolt in the spark plug hole, run the piston up to it on one side, mark the fly wheel, and do it on the other side as well. Half way between your two marks will be TDC at least close enough for ignition timing a street engine. If the threads aren't common, a modified spark plug would work. Knock the center out of an old one and braze in a rod.

Kurt.

 

[Boink]

Question: I've often been told that the true TDC is tricky to just "see" without multiple measurements either side of it. Specifically, that the very last tiny part of the piston stroke will move the timing wheel a fair bit. True?

Even when I used a meter (with the head off), it was nearly impossible to get it right on without that back-and-forth multiple measurement (where one splits the difference).

 

[Rut]

Question: I've often been told that the true TDC is tricky to just "see" without multiple measurements either side of it. Specifically, that the very last tiny part of the piston stroke will move the timing wheel a fair bit. True?

Even when I used a meter (with the head off), it was nearly impossible to get it right on without that back-and-forth multiple measurement (where one splits the difference).

Mark,
The slack in the timing chain and movement of the piston make a piston stop a very reliable way to set tdc. A gauge is good with the head on or off, but I still use measurements on both sides and split the difference. A good piston stop can be as simple as a bolt with a lock nut screwed in the spark plug hole.
Rut

 

[Boink]

Thanks Rut! I guess my only point was that it seems the harmonic balancer wheel can move a fair bit with an imperceptible movement of the piston right at top. Yes, forgot about the timing chain slop too. So, the dual measurements and splitting the difference seems like the safest way to be sure.

 

[Bayless]

Boink, for the reason you stated, it's best to mark a few degrees away from TDC on either side.

 

[Boink]

 

[Gerard]

Question: I've often been told that the true TDC is tricky to just "see" without multiple measurements either side of it. Specifically, that the very last tiny part of the piston stroke will move the timing wheel a fair bit. True?

Even when I used a meter (with the head off), it was nearly impossible to get it right on without that back-and-forth multiple measurement (where one splits the difference).

There is some dwell at the top of the stroke, so doing that is SOP and a must, especially if you are timing the cam.