backfire on startup

alan hodge · Jul 31, 2019

N4Gs arrived today along with thunderstorms so no riding yet to try them out.....was pleased see four plugs in box for $9.95 two will be going in my 72 T120 I recalled back around 1971-ish I used N4Gs in my CZ MX bike.....got em for free from US distributor in exchange for putting Champion sticker on rear fender...…..another CZ memory the first thing to do was remove the PAL sparkplugs and put the Champions in and the second thing remove the Jikov carb and replace with mikuni.

htown16 · Jul 31, 2019

Could be the battery was bad. The Pazon ei works not by increasing the advance with more rpm but by retarding the advance with less rpm. So if the battery isn't putting out enough juice the box will be over advanced at starting and low rpm. Kickback at starting or low rpm is often a tell tale that the box isn't getting enough power.

alan hodge · Aug 1, 2019

battery prolly played a role with headlight and ignition switch on it dropped to 10V in seconds and only slowly climbed up to 12.2 ..it was just 2 years old but put on trickle charger many many times

htown16 · Aug 1, 2019

Yep, a battery with those symptoms will definitely mess with the ei. About 3 years is all I ever get out of a battery. Heat and vibes are hard on them. I'd try going back to the recommended plugs. Always make's me nervous to run a hotter plug. May work fine 99% of the time but all you need is right conditions, bit of bad gas, going up a grade, rolling throttle on in too high a gear ect to get detonation and then damage is done.

alan hodge · Aug 1, 2019

gonna try the N4Gs as an experiment when rain stops...…...new battery made bike 'back to normal' glad I don't have a BB ignition on it as I know from experience on my 72 T120 once 12V and below means 'stop'

htown16 · Aug 1, 2019

Pazon is more forgiving but the Boyer MkIV is also versus the older MKIII.

HRD · Aug 4, 2019

MichaelB said:
Why not jet it correctly? I would. I would buy a handful of pilots and start from there.,
Buy the jets here https://www.jetsrus.com/
If you can turn the mixture screw out more than 2 1/2 turns and it doesn't falter, you're too rich.
My 750 Combat didn't clean up till I got it down to a 25 pilot and a 240 main.

BTW, one of the best investments ever was the Mikuni carb tools.
I use them on EVERY carb, including Amals.
They have the correct driver tips. I haven't buggered a screw or jet since getting them.
And, they ONLY come out for Carbs, nothing else.......

That cross head driver look like a JIS driver ,made for Japanese made cross head screws , also made to slight different standards/fit to Phillips head screws .The JIS driver can be used on Phillips cross head screws but the Phillips driver( unless modified) should NOT be used on JIS cross head screws as it will tear out the corners.JIS cross heads are normally marked near the + with a single dot.
Paul

Mark Savage · Aug 4, 2019

HRD said:
That cross head driver look like a JIS driver ,made for Japanese made cross head screws , also made to slight different standards/fit to Phillips head screws .The JIS driver can be used on Phillips cross head screws but the Phillips driver( unless modified) should NOT be used on JIS cross head screws as it will tear out the corners.JIS cross heads are normally marked near the + with a single dot.
Paul

I have a few JIS screwdrivers and although I no longer use them for JIS fixings I have found they fit Phillips screws better than my Phillips screwdrivers sometimes.

alan hodge · Aug 4, 2019

ran bike about 45 miles this morning with N4Gs ran perfectly throughout range plugs lite chocolate color

backfire on startup

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