When it rains it pours!

[sicivicdude]

I ordered new spark plug boots (thanks Jess for having those problems and opening my eyes!) this afternoon so they'll be a day or three in the mail.

I have the one functional coil I could fire it up on but I'd just rather wait anyway... plus I still didn't stop by the hobby shop to get another gallon of fuel.

 

[cole454]

Bad A$$

151515

 

[blasterfreek30]

I ordered new spark plug boots (thanks Jess for having those problems and opening my eyes!) this afternoon so they'll be a day or three in the mail.

I have the one functional coil I could fire it up on but I'd just rather wait anyway... plus I still didn't stop by the hobby shop to get another gallon of fuel.

might be a dumb question but obviously the plugs will fire at the exact same time right, they have to.. im by far an electrical kinda guy lol so i dont really understand how u pulled this off:-/

 

[sicivicdude]

The secret is in the wiring harness.... I started with some basic questions about how the CDI do their internal timing ignition advance and how they regulate the outgoing "trigger" voltage to the coil. These led me to a MASSIVE black hole which is the CDI box and how yamaha manufactured it. Basically there's NO information on how it's made or how it works so I came up with a work around.

Knowing that each ignition system has 5 main parts (read : necessary) I worked backwards to the CDI box instead of from inside it. Those main parts are: source coil, trigger coil, CDI, kill switch, and ignition coil. Those all have to work together to get the power in and power out at the exact right time (and finally to stop the power when you want to LOL)

Knowing each CDI is "fed" power from a source coil I began to look at the stator plate. I noticed that except for thickness (and mounting post height due to that thickness) the source and lighting coil look identical. I cut two thin aluminum "washers" and installed another source coil where the lighting coil was and hooked the second source up to the lighting coil wire on the stator plate.

Once into the "main harness" I ran both source coil wires to the front, both orange ignition coil wires to the back and then branched the trigger coil wire and the ground coming off the stator plate into each CDI box. If everything works according to plan both CDI's will "see" the timing (according to the trigger coil) at the same time and run parallel ignition timing curves and trigger their own coil at exactly the same moment. I even took the extra steps of making the orange ignition coil driver wires the exact same length and the trigger coil wires after the branch the exact same length.... just in case.

That's as good as a po' boy can do for running twin ignition systems. If this doesn't work (which it should but just sayin'), it's back to the drawing board to figure out how to stack two trigger coils.... or perhaps I'll just skip that step and go straight to COP (coil-on-plug) and an aftermarket ignition driver box. Who knows!

 

[Prime]

The secret is in the wiring harness.... I started with some basic questions about how the CDI do their internal timing ignition advance and how they regulate the outgoing "trigger" voltage to the coil. These led me to a MASSIVE black hole which is the CDI box and how yamaha manufactured it. Basically there's NO information on how it's made or how it works so I came up with a work around.

Knowing that each ignition system has 5 main parts (read : necessary) I worked backwards to the CDI box instead of from inside it. Those main parts are: source coil, trigger coil, CDI, kill switch, and ignition coil. Those all have to work together to get the power in and power out at the exact right time (and finally to stop the power when you want to LOL)

Knowing each CDI is "fed" power from a source coil I began to look at the stator plate. I noticed that except for thickness (and mounting post height due to that thickness) the source and lighting coil look identical. I cut two thin aluminum "washers" and installed another source coil where the lighting coil was and hooked the second source up to the lighting coil wire on the stator plate.

Once into the "main harness" I ran both source coil wires to the front, both orange ignition coil wires to the back and then branched the trigger coil wire and the ground coming off the stator plate into each CDI box. If everything works according to plan both CDI's will "see" the timing (according to the trigger coil) at the same time and run parallel ignition timing curves and trigger their own coil at exactly the same moment. I even took the extra steps of making the orange ignition coil driver wires the exact same length and the trigger coil wires after the branch the exact same length.... just in case.

That's as good as a po' boy can do for running twin ignition systems. If this doesn't work (which it should but just sayin'), it's back to the drawing board to figure out how to stack two trigger coils.... or perhaps I'll just skip that step and go straight to COP (coil-on-plug) and an aftermarket ignition driver box. Who knows!

Dual triggers is a good idea. Also, if you do end up going with two trigger coils, you should try timing the plugs separately!

 

[blasterfreek30]

i think i understand ya, my next question is..having 2 trigger coils in diffrent spots is the extra one u added gonna act somewhat like advanced timing because its not being triggered in the same spot as the stock one, therefore casueing it to fire after the first one is triggered...i see what u were saying about stacking them, is that why?..again sorry for the dumb ?? dude

 

[sicivicdude]

I like the IDEA of just ever so staggered trigger coils to "advance" the timing well beyond what's physically possible by just turning the timing plate BUT finding a place to put a second trigger coil which is in line with the magnet buried in the flywheel it needs to be is going to be tough with limited space under that flywheel. Now, with an external rotor flywheel..... MUHAHAHAHA thoughts for another day....

My comment about figuring out how to "stack" the triggers was more or less literal. I would have to figure out how to put them darn near on top of each other but get them both to see a timing event simultaneously.... Very difficult.

No dumb questions except those which you may be too embarrassed to ask and remain unanswered...

 

[N8tsNastyBlasty]

bet the cdi has an ic chip that has the advance curve programmed base on trigger rpm.someone will have to open one up and reverse engineer it.

 

[sicivicdude]

AHHH but then I figured out there's another possiblity...

The voltage of the source coil rises with increased rpm. It's possible the CDI uses the trigger coil as the "start" timing point and then uses the voltage rise as the "multiplier" for the digital advance. That part is what scared me...

 

[FLOTEK]

definitly not what i would do *but i gotta give you credit for atleast attempting such unorthadox engine building practices lol
before you race this please double check your chassis tires a arms ect.. and how your setting this up ,mistakes happen fast on a track and sometimes cant be corrected .. id hate to see you get hurt or anyone for that matter so use your head and be safe ,if it looks iffy -dont do it

 

[sicivicdude]

Thank you for the credit for unorthodox engine building practices at least.

I actually asked for opinions of builders who might have any experience with this sort of thing and got no replies.... so I pressed forward myself and did a little "experimenting". We'll see come Spring how this combo works. The track times will tell the tale....

 

[sicivicdude]

My red label wheels arrived yesterday. One douglas red label and one DWT .190". Not sure what the difference is between the brands, the rims look identical even down to where the welder doubled back to seal off the beginning of the weld.

I'm going to do a "chinese tire drill" (pun completely intended) and put the kenda Kutter XCR's off my wife's quad on the red labels and on the yellow blaster, the black labels on the dragger with TBA tires, and the ITP delta steel's with the maxxis RAZR's off the yellow blasty on my wife's blaster. Convoluted... but that puts the lightest rims I have on the dragger, the strongest wheels and best tires on the blaster that gets trail ridden, and my wife's blasty still gets good tires on it....

 

[StrokedTater244]

from what i have seen over the years they are the exact same wheel. one might be a few years older/newer than the other.

 

[sicivicdude]

from what i have seen over the years they are the exact same wheel. one might be a few years older/newer than the other.

They look exactly same except for the label! LOL I'll probably take the labels off and polish them up a bit (they're already shiny as crap just a few scuffs and stuff that needs to be cleaned up or I wouldn't even bother) and run them.

 

[StrokedTater244]

They look exactly same except for the label! LOL I'll probably take the labels off and polish them up a bit (they're already shiny as crap just a few scuffs and stuff that needs to be cleaned up or I wouldn't even bother) and run them.

sounds like you got some nice wheels for your trail quad there. I:I

 

[sicivicdude]

sounds like you got some nice wheels for your trail quad there. I:I

Heck yeah. I made an offer of $50 and the guy accepted.

 

[CARNZ]

i always thought DWT = Douglas. i figured it was like douglas wheel tech or something lol. i have never noticed a difference them besides age

 

[sicivicdude]

VERY possible that's what it means. Either way they look to be a matched set except for the labels. Pictures tonight!

 

[yzrider]

dwt is douglas wheel tech. they are the exact same, sounds like u got one hell of deal

 

[the_mrs]

My red label wheels arrived yesterday. One douglas red label and one DWT .190". Not sure what the difference is between the brands, the rims look identical even down to where the welder doubled back to seal off the beginning of the weld.

I'm going to do a "chinese tire drill" (pun completely intended) and put the kenda Kutter XCR's off my wife's quad on the red labels and on the yellow blaster, the black labels on the dragger with TBA tires, and the ITP delta steel's with the maxxis RAZR's off the yellow blasty on my wife's blaster. Convoluted... but that puts the lightest rims I have on the dragger, the strongest wheels and best tires on the blaster that gets trail ridden, and my wife's blasty still gets good tires on it....

You butt. I wanted both of my rides to have Kenda's.