Advancing Ignition

HT60CC · #1 07-26-2008, 04:22 PM

I'm interested in the idea of advancing the ignition on these engines but I have not idea of how to do it, yes I have heard of the remove base gasket trick which has the effect of advancing the ignition as the piston would be closer to TDC at spark.

has anyone ever tryed a different CDI or even tryed opening up the existing one, I seem to recall someone has tryed it before.

jasonh · #2 07-26-2008, 05:25 PM

I think Norman was working on dissecting a CDI. I've been looking for a replacement CDI, but ours is not the traditional CDI. Most CDI's have a constant power source and constant ground, and it receives a "fire signal" coming from a secondary magnet/coil on the flywheel...in other words they use a minimum of 3 wires, unlike our 2.

Easiest way to advance ignition I would think would be to slightly adjust the magnet position in the magneto. But changing it just a couple degrees would be very difficult with the design.

Removing the base gasket won't affect ignition timing. The piston will be in the same spot in it's stroke compared to the magneto position. It will however, change intake/exhaust timing (i.e. when the ports open/close)

**Dave31** · #3 07-26-2008, 05:48 PM

We've been working on this for a while...I have not found any components that would work to improve it and have found no way to improve what we already have.

Read more about it here........http://motorbicycling.com/f13/beefed...ition-647.html

Egor · #4 07-26-2008, 11:13 PM

I have done some advancing, from just slight to a full key. I have now removed the advance completely and am just running the stock. The problem was that the engine got finicky and the other thing is that these engines will not last at high revs so for torque and low end power I like them stock. I have a lot of porting and a larger carb 18mm and I think for me that is enough, the bike will do 40 with a 39 tooth sprocket and climb some big hills around hear, I get the most out of the porting, I don't even change the intake tube. Let us know if you have any luck with the changes. Have fun, Dave

PS: I forgot to tell you how I did it. I file the slot in the rotor and then make a small wedge to fill the gap. You can then just move the filler over to the opposite side if you want to return to normal.

eDJ · #5 07-27-2008, 07:50 AM

I would urge the inexperiencd to procede with utmost caution. Air cooled engines may not have as wide a latitude of tolerance as water cooled. For the small increase in power it may cost in a failed motor. If this is done enrichening the fuel air supply should be considered.

Venice Motor Bikes · #6 07-27-2008, 09:40 PM

Yeah... I would say don't mess with the timing unless you REALLY know what you're doing!!
You could also end up making the engine run really hot!!!
You can get plenty more speed & power from gear changes, a good plug, wire & boot, & simple porting!!

**Norman** · #7 07-29-2008, 11:16 AM

I'm going to throw a monkey wrench into the soup.
To advance the timing and not destroy parts I take an over sized woodruff key and dremel it to make an off set key to advance or retard the timing a few degrees. I need to sit down some time and put my timing light in these engines to find where it's firing spot really is. then a guy would know if changing the timing would be of any use.
Any of you guys remember a bike called a Hodaka? I've wondered if the parts off the old hodaka would fit these china engines?! I remember the Hodaka would run like a scalded dog and were lots of fun.

Egor · #8 07-30-2008, 01:10 AM

I raced Hodaka's and thinking back, I don't think any of the parts would fit. There is a chance that parts from a chain saw would work. But the only reason to use them would be to in crease the quality of parts. I have used some of the porting skills I learned from the Hodaka on these engines. one thing about points is that it is easy to change the timing and see what you have. I am looking forward to hear what the timing is on these engines stock. Like I said I moved timing up about 1/2 a key and then a full key, but it wanted more fuel and got fussy I didn't like the way it ran slow. Have fun, Dave

eDJ · #9 08-05-2008, 11:09 PM

Yeah those offset woodruff's will do it for advancing or retarding a 2 stroke flywheel or on a timing gear to advance or retard a camshaft on a 4 cycle engine.

I'd bet the expansion chamber would be the best route to go for performance tuning....and just keep the stock timing settings.

Easy Rider · #10 08-05-2008, 11:52 PM

Quote:

Originally Posted by Norman

To advance the timing and not destroy parts I take an over sized woodruff key and dremel it to make an off set key to advance or retard the timing a few degrees. I need to sit down some time and put my timing light in these engines to find where it's firing spot really is. then a guy would know if changing the timing would be of any use.

Hey Norm, Do you think a rocket key work?

Goped Rocket Key - Go Ped Rockit G23LH G43