What make of spark plugs?Problem Solved!!!!

[beemer]

What's the best make of plugs for my 65LS,she's refusing to start!!!iv'e cleaned the carbs today,didn't reset anything,but she splutters and backfires and then won't do anything,i have NGK's fitted,but i want to change them since this problem may be a searce and find project if it's not the plugs,iv'e been through the wiring and earth's today also,so next is plugs and fingers Xed!!!any advice please?thanks,J.

[Chris_in_BC]

NGK BP7ES work fine.

But my guess if you have just worked on the carbs, that is the place to look. You say you didn't reset anything, but if you clean the insides at all then you had to remove jets. Sure all back correctly? And the correct number of turns backed out etc.

[beemer]

Yes i i wrote it all down to make sure it goes back the same,let's see what happens when i replace the plugs,the reason i think it may be the plugs are,i took them out and cleaned and reset the gap and she fired up but that didn,t last,if it's still a problem maybe i should start from the beginning and adjust the carbs ?any thought on this?thanks,J.

[Bob_Roller]

Did you have this problem before you started working on the carbs ?

[airhead]

I second wholeheartedly the logic of if you worked on the carbs, that's where the problem will be. Both plugs wouldn't break down at once and the engine will still run on one.
Go through EVERYTHING you did just before this happened. Did you pull any HT leads for example, are the chokes on the carb the right way round (VERY easy to get them the wrong way), is fuel flowing etc etc?
Use logic man!!!!!!


Bill.....................

[Bill90Loyale]

Double check your choke cables at the carbs.   Are they fully opening the chokes on both carbs at cold start?

[Bob_Roller]

Did the throttle and 'choke' cables get swapped at the carb(s).

[beemer]

Did you have this problem before you started working on the carbs ?

Yes i did,but iv'e been through everything except plugs HT leads,one step at a time i guess.

[scuba]

you already have backfire which means that you have spark(s) on plug(s). that leaves you only carbs to check. something is now different than before. bring it back to previous.

[beemer]

Did the throttle and 'choke' cables get swapped at the carb(s).

No,cables on correctly,i'm also wondering if the HT coils may be the problem,as i said,one thing at a time.

[Bob_Roller]

What condition is the spark at the spark plug ?

A bright blue/white, or more of a yellowish color ?

If you have the original gray / black case ignition coil, it may be a possible cause .

It's a common failure part on our bikes .

[Justin B.]

I don't know if you ever answered the question as to whether it was doing this before you messed with the carbs?  Did you have the enricher assemblies off and apart?  They are easy to get back together wrong and they are "sided"...  My last .02 until Monday...

[beemer]

I don't know if you ever answered the question as to whether it was doing this before you messed with the carbs?  Did you have the enricher assemblies off and apart?  They are easy to get back together wrong and they are "sided"...  My last .02 until Monday...

Yes it was doing this,i rode it last Saturday and it was going really well,came to go out on it on Sunday and it wouldn't start,checked standard things,but no go!plenty of fuel in carb bowls,plugs looked ok,ht leads,so i'm just working my way through it bit by bit,some wire may have come adrift?another thing i was reading about in the Haynes manual was the stop switch on the handlebars,bad contact they say,could be a problem,have you heard about this?

[Rob Valdez 79 R65]

I have heard of the Stop switch going bad.  A test (if you are lucky) is to work it back and forth a few times, and see if that clears it.
I suppose you could even remove the switch from the circuit (find the appropriate plug) and test it with a volt-ohm meter.  

[beemer]

I have heard of the Stop switch going bad.  A test (if you are lucky) is to work it back and forth a few times, and see if that clears it.
I suppose you could even remove the switch from the circuit (find the appropriate plug) and test it with a volt-ohm meter.  

Regarding the stop switch,in the Haynes manual they say to spray it with a cleaner,i'm not sure where you would spray?is it easy to take off the plastic cover and get to the switch?I haven't touched anything before it started to give trouble,so i will have to just gather as much info as i can from you guys and check it out,thanks for all the advice,please keep it coming!