Advancing Ignition

I dyno tune cars for a living.....
timing for fuel economy & power are one & the same
you want the timing as advanced as you can get it without causing damage to the engine
check out Jak Stoll Performance
I dont mean to be a ****e I just wanted the information strait
take care
JAK

Hi
I know that as much advance as possible with lean af ratios are for economy
And for power the minimum advance for the max power is the best (safe af ratios)
I tuned a number of megasquirt ecus
Not trying to compare it to your work, just sharing what I learnt
Peace

A car ecu responds to engine parameters
Our china girls have fixed advance/af ratio
Peace

how many degrees btdc are these ht motors ? has any body used a dial indicator and a degree wheel to detirmine this because with the poor quality of these motors all in all i find it hard to believe they would all be exact if you had a baseline to go buy you could safely do it in 1 degree increments and find the sweet spot and then we could all try to optimize timing for our different applications but the truth lies in the baseline timing we need to know this before moving forward

Hi
Would be interesting to have data from the factory or see the original drawings...
Peace

I 've put a timing light on one of my engines and I do know the timing changes as you rev it up I believe it advances but that's as far as I've tinkered with it sometime when I'm bored I might put the degree wheel on it and find out exactly where it fires and where the advance is when wide open also where the ports open and close. but I got to get in the mood and lately I've not been there.

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norms-iron-works.tripod.com

I played with my timing considerably
Id have to agree with Jose above
when you advance the timing on these engines they just kind of flatten out with maybe a tad more up top
more retarded gives more torque
I set mine in the middle of the slop available in the key thats there which is considerable

I think shaving the head a tad & leaving the timing alone is probably the best option
take care
JAK

i think the transfer ports are to low just an opinion when in comparison to a couple other 2 strokers im playing with in relation to bore and stroke if i can find just a cylinder some where i would love to play with it and if you bring up the comp. then the motor may be able to run a little more timing but at a low comp. standpoint timing may not be an issue ive been pondering a interchangeable combustion chamber simaliar to a pro design cool head just to play with ratios but its a lot of work and results may vary it is what it is sometimes !peace !

I raised the transfer ports about one tenth of an inch. I didn't notice any improvement in the way it ran. I think long port timing on the compression side is intended for a high revving engine. I took a Honda CR250 apart a few weeks ago and took a few pics of the ports, they are very aggressive. It is not what these engines need, this engine is not intended to spin above 7,000 rpm. It would be interesting to hear about someone that was able to get one of these engines up near 10,000. It is interesting to hear that these engines may have an automatic advance in the ignition! I would suspect that we would see a very loose timing caused by the small rotor. Have fun, Dave

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Chuck - The monkey has the spark plug again!

I had a puch moped many years ago; all mods,ported,tuned pipe, bigger carb,gearing...Had the same problem with advancing timing even though it had a points system..Had the breaker plate maxed over...didn't help until I took the key off the magneto and moved it almost 2 keys worth..Than it really came to life...By the way didn't even use a key just set it and Torked the heck out of it with a long breaker bar....