1230 EFE - Cylinder 2 not running - firing on 3 only.

[Dukeman]

1230 EFE - Cylinder 2 not running - firing on 3 only.

Before I start stripping everything down to see what could be the issue I thought I would run this passed you lot for your thoughts.

Cylinder 2 header pipe is cold compared to the others.

 

Pulled the spark plug, it was black and appeared dry and did not smell of fuel.

Cleaned the plug and checked for spark and there was, running miniature Dyna coils, coil must be ok as cylinder 4 is ok running on the same coil.

Carbs are RS36 flat slides - opened the carb drain and fuel poured out from the bottom of the carb.

 

So it is leading to no fuel is getting to the cylinder.... where is the best place to start with these carbs?

I have not worked on these before......and I REALLY do not what to pull the carbs but may have to.

Any ideas?

 

[Askamaskinservice]

1-4 and 2-3 share coil, i guess you wrote it down wrong.

[PaulP]

I would swap plug 2 and 3 over as I believe they are on the same coil, they are on my es model anyway, I also spent some time tracing a non running no 2, it turned out to be because I had removed the tank but not blocked off the vac line to the fuel tap, this on mine is connected to no2 and giving a lack of vacuum, blanked it off and all ok, so worth looking to see if you have a vac leak

[Dezza]

2 hours ago, PaulP said:

I would swap plug 2 and 3 over as I believe they are on the same coil, they are on my es model anyway, I also spent some time tracing a non running no 2, it turned out to be because I had removed the tank but not blocked off the vac line to the fuel tap, this on mine is connected to no2 and giving a lack of vacuum, blanked it off and all ok, so worth looking to see if you have a vac leak

He has RS36s so there isn't a vac connector to leave blank to cause such problems. I had the same on my EFE engined bike and it was a faulty CDI unit. The 'runs on 3, so ignition must be OK as each coil is connected to either 1-4 or 2-3' is often a Red Herring. Has the bike been left for any length of time with fuel in the tank and carbs or is the tank rusty inside? If not I'd check out all the ignition connections and components first before stripping the carbs.

[PaulP]

Fair enough on the vac, but if 3 runs then swapping leads 2 and 3 should still tell you if it’s the ignition wouldn’t it ??

[Gixer1460]

Will only identify a duff plug or lead. Swap the LT side of the coils 1/4 to 2/3 and vice versa and swap the plug leads to test the coils. Personally - single cylinder problem? - carbs more than likely.

[Sheep]

Could number two be getting too much fuel as opposed to not enough?..I know you said it wasn't wet but a sooty plug would mean it's either rich or misfiring perhaps...My 1230 on rs's had the same issue once and turns out the fuel was a little rich on one cylinder and causing the plug to soot up,not a lot but enough to stop the spark in the chamber.

[Dukeman]

Thanks guys first step will be swap the leads with 3 and then a new plug....

if this does not fix it we all know what comes next!

[Dukeman]

I went straight to a new plug and bingo - that was easy, very pleased I did not have to pull the carbs.

Thanks for the advise.

 

[Gixer1460]

12 minutes ago, Dukeman said:

I went straight to a new plug and bingo - that was easy, very pleased I did not have to pull the carbs.

Thanks for the advise.

But why did it die in the first place? Getting it to run is one thing - keeping it running is another! Plugs are generally reliable - my daily's plugs are approx 40,000 miles old and still going strong - just sayin'