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| Chainsaw / Strimmer / Mini Moto Engine Ignition |
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| MrFluffy:
The answer seems to be that some are fixed timing, but others have components in which change the timing with rpm. From http://nswminimoto.forumup.org/about2633-nswminimoto.html :- "the Polini/Ducati/BZM coils are 'electronic'. They have some electronic componets (inbuilt transistor/capacitors/resistor/diode) configured to alter the spark advance at high and low rpm. At low rpm there is plenty of advance and at higher rpm the timing is retarded (in order to optimise) cylinder filling. I know that some will say that advancing the timing at higher rpms is a way to gain power, but if you only fill half the cylinder before ignition (advanced), then you actually lose power and blow out fuel straight out the exhaust port. The standard coils on Banshees and early model Blata's have a fixed spark interval. This is why you can also gain some power from your rep engine by changing the coil. However, some flywheels are not so compatible (the magnets' length and position) and keyway are located differently. A blata is a type of mini moto model, along with the polini etc. This also caught my eye, those of you who know msd products will already know the price will be expensive, but the quality amazing. Still too rich for my pockets at $240... http://www.gopeddepot.com/en-us/dept_70.html However, Ive also read in a couple of places that the go-ped stock ignition unit also has inbuilt spark advance. I think given the market that does go-ped tuning and their general level of technical expertise, I'd be happier to see the results of a strobe on the ht lead. However, I have two mini moto's in the shed and now Im curious myself. One is a classic small mini moto, the other is a dirt bike style one with suspension front and rear, and a chainsaw style motor. I agree we're probably overworrying about advance curves if its for a model motor. Its just in my application Im thinking of, i want as much power as it can give :) |
| NickG:
Think my mate has a polini. I was going to get it to play about with as he couldn't get it going but think he did now :( Interesting stuff. Nick |
| dbvandy:
hey look... A thread about what I did on my Webster.... It works wonderfully, but I have found that the idle needs to be about 1000 RPM in order to make a reliable spark, at least that is the case with my engine. Here is a video of me adjusting the idle... It is very nice to have a very portable engine all self contained. |
| NickG:
Doug, thanks for posting this under here to keep it together. Your webster is brilliant. I see you used the original flywheel from the engine and as I said I love the fact that you can adjust your timing easily. Do you think once the optimum or preferred position was established it would have been difficult to extract the magnets and hide them in a different flywheel or pulley on the crankshaft and maybe hide the ign module underneath? Nick |
| dbvandy:
Extracting the magnets might be damn near impossible... it looks like they are cast in to the flywheel. AND there is really no need to when you can get some really strong NEO's and just epoxy them into a new wheel... I looked into doing that and then decided to leave it as is and start to work on the Otto.... |
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