Spark plugs?

**kiwi cowboy** · 29th March 2008, 17:53

hi all
well ive got a 83 cb900 bol dor in my garage.
fella i got it off said it needed carbes seen to eas why it was running rough.
i think it is running a bit rich by the look of the plugs anyway i put a new set of plugs in it and it ran great for about half an hour then went back to running shit again so i took the no 4 plug out and tested it and it was sparking blue so put one of the oridginal ones cleaned up back in started and ran fine again.
did i get a bum plug brand new or is there somthing wrong posibly somwere in the electrics that would fry the plug.
the thing is theres a spare plug in the tool kit which seems funny to me.
any coments.
cheers

**TripleZee Dyno** · 30th March 2008, 06:43

Originally Posted by handle6

hi all
well ive got a 83 cb900 bol dor in my garage.
fella i got it off said it needed carbes seen to eas why it was running rough.
i think it is running a bit rich by the look of the plugs anyway i put a new set of plugs in it and it ran great for about half an hour then went back to running shit again so i took the no 4 plug out and tested it and it was sparking blue so put one of the oridginal ones cleaned up back in started and ran fine again.
did i get a bum plug brand new or is there somthing wrong posibly somwere in the electrics that would fry the plug.
the thing is theres a spare plug in the tool kit which seems funny to me.
any coments.
cheers

Hey
I would go with the previous owners suggestion. Carbs do "wear out" amd go out of adjustment, especially if they have been around for 25yrs.
Unlikely anything electrical is fying the plugs.

**jonbuoy** · 30th March 2008, 07:50

Plugs maybe fouling up with fuel and carbon, if you clean that plug up or dry it out it will probably go again, is it a pain to start? Time for the carbies to have a colonic...

**kiwi cowboy** · 30th March 2008, 09:39

Originally Posted by jonbuoy

Plugs maybe fouling up with fuel and carbon, if you clean that plug up or dry it out it will probably go again, is it a pain to start? Time for the carbies to have a colonic...

no it starts fine just idles and runs rough.
any idea whot it costs to roco these and whot i need to get cheers

**kiwi cowboy** · 30th March 2008, 09:43

Originally Posted by TripleZee Dyno

Hey
I would go with the previous owners suggestion. Carbs do "wear out" amd go out of adjustment, especially if they have been around for 25yrs.
Unlikely anything electrical is fying the plugs.

cheers i have a set of carbs here that came with the bike that have been recoed [apperently] might take them to the shop and get them checked out.
have been told to try one grade hotter in the bike to stop carboning how would that go in the mean time any thoughts cheers

**jonbuoy** · 30th March 2008, 11:44

You could go hotter but standard plugs should work fine, carb parts do wear out but might just need a clean out - no parts required.

**What?** · 1st April 2008, 19:31

Sounds like the needles are worn out; this would be expected at around 50-60,000Km.
I think (dynamic memory kicking in here) that they will set you back about $35 per carb, plus labour if you are not that way inclined.

**kiwi cowboy** · 1st April 2008, 19:52

Originally Posted by What?

Sounds like the needles are worn out; this would be expected at around 50-60,000Km.
I think (dynamic memory kicking in here) that they will set you back about $35 per carb, plus labour if you are not that way inclined.

yes maybe neddles they look ok but am told you cant see the wear its so minute so am getting a price for some cheers and bikes done 82000 ks but dunno bout the neddles but at least i can put them in myself

**pete376403** · 1st April 2008, 22:07

The coils are probably as old as the carbs - weak spark wouldn't have enough energy to burn off crud. Something else to consider.

**Kickaha** · 2nd April 2008, 05:22

Originally Posted by handle6

have been told to try one grade hotter in the bike to stop carboning how would that go in the mean time any thoughts cheers

You're better of diagnosing it and fixing it properly, have you checked that the plugs in it are correct for the bike?

**What?** · 4th April 2008, 11:30

Originally Posted by Kickaha

You're better of diagnosing it and fixing it properly, have you checked that the plugs in it are correct for the bike?

Good point - should be NGK D8EA.

**Katman** · 4th April 2008, 13:03

As has been mentioned, quite likely it's worn needles but you should always replace them in conjunction with the needle jets that they slide up and down in - which are even harder to actually see the wear in.

**vifferman** · 4th April 2008, 13:07

Katman!

I thought you were going to be at the MotoTT trackday?

**kiwi cowboy** · 4th April 2008, 21:41

Originally Posted by What?

Good point - should be NGK D8EA.

cheers everyone yup d8ea is wots in it and im also trying to get a new air filter as the one in it looks old and dirty and may not be helping but that was a week ago i asked the shop to ckeck the availability but havent heard back yet.