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Sat Sep 28, 2024 12:24 pm

If I use a timing light and set my timing to 5-8 degrees advanced the engine doesn't run well. If I add a bunch of advance(up to 35 degrees) the engine gains a lot of power. Shouldn't it run best at the recommended advance of 5-8 degrees? I'm confused about this. It is a type 4 2413cc with dual wannabe webber 44s and electronic ignition on pump gas. Any thoughts? Thankyou.

Sat Sep 28, 2024 12:51 pm

I would guess that engine would be happy with about 12 degrees of advance at idle. 5-8 is a little low, in my opinion. I am assuming single plugs. It’s going to take more time for the flame to cross the combustion chamber. If you have ‘73-‘76 2.0 heads off a 914, it may be happy with 10-12 at idle because the plug is closer to the center of the combustion chamber… but 5-8 is almost certainly to little advance.

How did you find TDC? If you engine won’t run unless you have stupid amounts of advance, your fueling is either whacked, or you have the wrong timing mark.

Sat Sep 28, 2024 8:33 pm

That depends on what you mean when you say "the engine gains a lot of power."

Does it pick up a bunch of RPMs sitting there at an idle or does it run better driving it down the road?

Kicking in more timing advance at an idle can cause the RPMs to go up but it will run worse going down the road.

If it takes 35 degrees advance to make it run good going down the road, you're either doing it wrong or somethings wrong with your engine. The pulley slipped the keyway or the distributor is in wrong.

Sun Sep 29, 2024 8:02 am

T4 timing marks are goofy as owl shit and have many variations, pretty sure some even just have an ATD mark? Ive had to look it up before on one that i had and then count fins. Assuming OP has all normal stuff right , thatd be something id double check

Tue Oct 01, 2024 8:54 am

There were many variations depending one the engine type. All had different timing requirements.

The OP needs to provide us with more information on how he found TDC to determine if his timing is accurate, or if he is referencing TDC incorrectly.

Wed Oct 02, 2024 1:59 am

Being familiar with the timing mark confusions with this engine I made sure to mark the pulley the last time I had the engine opened up so I know for sure it's #1 tdc. So if I advance the timing any further it goes into the danger zone where the engine rattles and pings and such. I know what's going on there and of course i stay away from that but The engine runs best just before that. It does have big valve heads , cam unknown. It revs a bit higher and the mid range power increases substantially at this timing setting. Carbs are new ,just cleaned. Low end power is OK has been better at different timing. Top end doesn't really exist on this engine, I've never seen any before. Goes pretty flat around 3500-4000 rpm's I think. No rpm gauge. I'll check the timing again with the light and get an exact # for you guys. Thanks for the help.