Honda-SOHC

SOHC.co.uk Forums => CB350/400 => Topic started by: Harrier want to be on May 22, 2022, 08:14:53 PM

Title: Number will not firer
Post by: Harrier want to be on May 22, 2022, 08:14:53 PM

I have changed the coil plug and cap but will number 2 won’t firer
When I take the plug out there is a spark
Any ideas please

Title: Re: Number will not firer
Post by: Johnwebley on May 22, 2022, 08:24:11 PM

Is the plug wet?


Check petrol in the float chamber,

Check the jets are clear in the carbs,

Try swapping one of the plugs that does work,

And fit the dead plug in that cylinder

Occasionally, you can get an iffy plug

Sent from my SM-A750FN using Tapatalk

Title: Re: Number will not firer
Post by: Nurse Julie on May 22, 2022, 08:57:38 PM

What type of plugs are you using? Are they all old or new? What type of plug caps are fitted? Swap the plugs as John suggested, if no different, do a compression test.

Title: Re: Number will not firer
Post by: Harrier want to be on May 22, 2022, 09:28:45 PM

Quote from: Johnwebley on May 22, 2022, 08:24:11 PM

Is the plug wet?


Check petrol in the float chamber,

Check the jets are clear in the carbs,

Try swapping one of the plugs that does work,

And fit the dead plug in that cylinder

Occasionally, you can get an iffy plug

Sent from my SM-A750FN using Tapatalk

I have done all of the above , compression is good , plug is new , coil is new changed cap
Plug is wet ?

Title: Re: Number will not firer
Post by: Johnwebley on May 22, 2022, 09:51:01 PM

Quote from: Harrier want to be on May 22, 2022, 09:28:45 PM

Quote from: Johnwebley on May 22, 2022, 08:24:11 PM

Is the plug wet?


Check petrol in the float chamber,

Check the jets are clear in the carbs,

Try swapping one of the plugs that does work,

And fit the dead plug in that cylinder

Occasionally, you can get an iffy plug

Sent from my SM-A750FN using Tapatalk

I have done all of the above , compression is good , plug is new , coil is new changed cap
Plug is wet ?

Wet with petrol,



Sent from my SM-A750FN using Tapatalk

Title: Re: Number will not firer
Post by: Harrier want to be on May 22, 2022, 10:49:28 PM

Yes

Title: Re: Number will not firer
Post by: McCabe-Thiele (Ted) on May 23, 2022, 12:34:03 AM

You will know the expression if there is fuel, compression & spark at the right time the cylinder should fire.

Is it a nice strong spark or could it be failing under load?

Title: Re: Number will not firer
Post by: Oddjob on May 23, 2022, 01:34:54 AM

I’m betting number 2 carb is flooding and causing the cylinder not too fire as there is just too much petrol in that cylinder. Try taking the plug out of no2, turn off the petrol, leave it for a day or so to allow for any excess petrol in the bore to evaporate and without turning on the petrol refit the plug and see if it starts then.

If it does you know it’s carb related.

Title: Re: Number will not firer
Post by: Harrier want to be on May 23, 2022, 06:39:28 AM

Thanks I will give that a try

Title: Re: Number will not firer
Post by: Harrier want to be on July 29, 2022, 11:12:27 PM

It turned out the carbs were so out of sync that number 2 wasn't  sucking