air r dual plug motor, how was it done?

[monster 84r]

this motor on ebay is a dual plug, but the head looks stock, did anyone ever make dual plug setups? heres the link, http://cgi.ebay.com/ebaymotors/honda-atc-250r-engine-250r-250_W0QQcmdZViewItemQQcategoryZ43977QQitemZ4623898 987QQrdZ1

[RideRed250R]

you can have the head machined for a second plug..... it probably wont do anythign without a higher compacity coil and upgraded ignition... plus you ahve to splice for a second spark plug cap...
Adam

[old honda dealr]

More then likely it is an odyssey top end. They have dual plugs. It is also a 250cc 2 stroke. I know there is also a 350 but that one looks like the fl250

[turboaddict]

my old ktm had a dual plug head... however it was just used so that in the heat of competition if you fouled a plug you could swap the plug wire to the other plug and be on ytour way.

[dizasterzrfun69]

i originally thought it was a fl250 head but it's not. It's not an 83 fl250 anyway. I have one out in the garage and i checked and the heads are different (bolt patterns).


Kevin

[bones200x]

my old ktm had a dual plug head... however it was just used so that in the heat of competition if you fouled a plug you could swap the plug wire to the other plug and be on ytour way.

The way I see it, A plug not firing is fouling? If the "other plug" is just sitting there, not firing. It has fuel/oil on it all the time. So if the "firing" plug is fouled so is the good plug? I maybe wrong....

[bones200x]

In order to have both plugs fire at same time... Go to a salvage yard and buy a Street bike coil with 2 spark plug wires on it. It doesn't matter if they are on the same side of coil or not. Almost any street bike coil is ok.

[BigGreenMachine]

Search "TC head" in this forum and you should find your answer by Catfishwhisker. It has basicly something to do with higher compression motors needing a stronger spark? Basicly a mod that would be overkill on a stockish motor.

[MTS]

Its pretty simple to do, Just have o grind down the fin's and drill/tap another spark plug hole...Kinda pointless tho.

[TimSr]

The way I see it, A plug not firing is fouling? If the "other plug" is just sitting there, not firing. It has fuel/oil on it all the time. So if the "firing" plug is fouled so is the good plug? I maybe wrong....

You are both right. It was common practice on many two stroke bikes in the 70's, with that theory in mind, and the practice was discontinued because it didnt work very well for the reasons you mentioned.

[88 Turbo Coupe]

The only time i foul is when I start after a carb mod at home. I never ride without my carb set up right. What else would cause you to foul???