Matt_S3_RX7

can anyone please help me with an "idiots guide" to setting the correct timing on the stock 12A engine, i have the haynes manual and the mechanics manual but i still need more detailed instructions on how to check and set the correct timing.

The mechanics here in Australia break into a cold sweat when i ask them if they can do a decent job of tuning a 12A engine (or anything to do with the RX7 in general). so im going to have to take matters into my own hands and is the only way ill learn.

Then engine and carb are stock NA (no porting or turbo), the only mod is a set of extractors.

Thanks guys. Matt.

Jeezus

iTrader: (4)

Look down at the dizzy. On the 2 dashpots you should see a vacuum line coming from each, unhook them and plug them up with a screw or something, so it will not cause any leaks. Next you will see a small 10mm bolt (I think its 10, maybe 12) on a tab that you can use to twist the dizzy left and right. Hook a timing light on the L1 plug wire (be careful not to have the pickup too close to other wires, it will cause interference) and aim the timing light at the main pulley. There should be a yellow dot and a red dot (it is red on my car, different colors for different people). The yellow dot is leading and red is trailing. Look at the very tip top of the pully and at the block, there should be what looks like a needle sticking out. Grab the dizzy and loosen the bolt previously mentioned. Twist the dizzy left or right and get that yellow dot lined up. Once that is lined up, tighten the dizzy back down. Now comes the trailing. Find a phillips head screwdriver and loosen the dashpot closest to the bolt you just adjusted. This dashpot has 2 screws and can be slid around. Snag up your timing light and hook the pickup end on the T1 plug cable, again, far enough away to keep interference gone. Aim the timing light at the pulley and look for the red dot. With the dashpot loosened, pull it toward or away from the dizzy and get that red dot lined up. When that is done, tighten the screws and reattach the vacuum lines. Your good to go!

Jeezus

iTrader: (4)

All that is with the motor running of course....

Matt_S3_RX7

Thanks heaps for that mate, i checked it and both the leading and trailing were in line with the indicator on the engine, but after revving the engine and checking it again the leading seemed to have moved? the engine has done 175000km so i think shes on the way out?

You were right about the gunk on the marks, they were almost gone and there was only a fient sign of them. but after putting some white-out on there i was good to go.

Both the marks on the pully were white on mine? but one of them had an indent.

Jeezus

iTrader: (4)

If you are revving the engine and you see it move that is the advance.

Rogue_Wulff

If the timing changed at idle, after revving the engine, a couple things may have happened. The dizzy hold down bolt may not have been snug enough, allowing the dizzy to move, the mechanical advance may be sticking, or you could have vacuum remaining in the vac advance hose if you had hooked it back up.
It's also possible the dizzy is just old and wore out.

Matt_S3_RX7

i take it the mech advance is a replacement job?

Rusty Shackleford

on my car i can time the leading but when i hook up the trailing and move the pot in and out...the knotch never moves.............. what is with this?

dbragg

iTrader: (7)

^^ yeah i have exprienced that also. so has my neighbor..