|
Title: My mag is fighting me Post by: Peter on May 24, 2012, 20:50:29 pm hello guys,
yeah, another magneto topic :) i bought a scintilla and wanted to see if it has advance or not... so..installed it...0,5 mm plug gap, with the cigarette paper i set the advance to about 15° but it wouldnt start.. advanced a bit... then it started and was running and then died again... now not possible to start anymore? is there a trick with these things? the engine should run fire up from 10- 30°, right? worth to mention is that the engine runs fine with other ignition, so its not carb related Peter Title: Re: My mag is fighting me Post by: TexasTom on May 25, 2012, 21:50:37 pm How much gap do the trigger points have?
TxT Title: Re: My mag is fighting me Post by: Peter on May 25, 2012, 23:44:59 pm hello Tom,
fiddled a bit more today and got it running again... i could check the advance finally, and i need to modify the mag... the advance goes up to +- 45° when the rpm's go up.. i set it statically at 15°, so i need to find a way so it advances max to +- 30° Title: Re: My mag is fighting me Post by: Ole on May 27, 2012, 22:00:47 pm 45° advance :o :o
Then you'd have to start the engine at 15° AFTER TDC... Or do you get 45 if set to 15 static? If so it's still 30°. Most "stock" Mags come with 12ish advance. If it's a race car just lock it, if it's a street car put it to 20-22°. Ole Title: Re: My mag is fighting me Post by: Peter on May 28, 2012, 11:28:48 am Haha Ole, i know :)
i thought this is a stock one (it came off an industrial engine the seller told me) maybe my timing light is playing tricks on me ? allthough it works fine with the electronic ignition.. I just revved the engine up to see the advance...No driving with 45° :) i also didnt rev higher, so advance might have been even more at 7000? on the mag it says: 0° at 400 and 12° at 1750 i think... so thats why i set it statically at 15 to get around 28 full out... but it advances further.... I thought it could be due to the engine running faster than 2000 and pushing the advance weights further than they should be? or is there a stop somewhere that stops the weights? i tried to open it up, but i dont have the correct tools or knowledge about them, so i couldnt take a look at the weights..these things are made to never take apart!! cheers, Peter Title: Re: My mag is fighting me Post by: sam P on May 30, 2012, 23:44:45 pm RPM and degrees marked on the magneto are camshaft degrees.
x2 for crankshaft degrees, that makes: 0° at 800rpm, 24° at 3500rpm. 15° initial advance is too much, give it 8° initial, this should give you 32° at 3500rpm. Llisten to your engine when you drive it hard. ;) Title: Re: My mag is fighting me Post by: Peter on June 04, 2012, 14:36:37 pm thanks Sam!
I ll try it |