Plug grade on the 550

[oldbiker]

I tend to use the B8ES for all the Suzuki triples. For good or bad. And I have the 380/550 and 750. I know the 550J should have B7ES and the 750L should use B6ES

I was wondering if all the 550 range had the same plug grade. Or if the JKLM models all had B7ES

I have a 550 with an "L" model engine and think I should try the B7ES plugs for a while. I think the B8ES are too cold a plug.

Ta
OB

[barney01]

As far as i am aware J K models had BP7 ES and later models had BP8 ES.
The Suzuki Data Manual page is below

[canaletto5]

I tend to use the B8ES for all the Suzuki triples. For good or bad. And I have the 380/550 and 750. I know the 550J should have B7ES and the 750L should use B6ES

I was wondering if all the 550 range had the same plug grade. Or if the JKLM models all had B7ES

I have a 550 with an "L" model engine and think I should try the B7ES plugs for a while. I think the B8ES are too cold a plug.

Ta
OB

Any reason why you think the standard is too cold? Kev

[Alan H]

It really depends how you ride. If you 'pootle' about go one grade hotter (smaller number on ngk) if you like to use the upper end of the rev counter a lot use the higher numbers. Hippos tend to be used with less revs and run cooler anyway, so stick to recommended or 1 grade hotter plugs if you're a steady rider.
I use 7s in the Hippo and 8s in the 550s, run in on 1 grade hotter for the first 100 miles until the fog clears.
I recall that my first 550 used B77ECs, but that had been breathed on by Crooks Suzuki. I was 21 at the time and pootle hadn't been invented back then.....

[oldbiker]

Right.... a bit side tracked by a 4 cylinder Honda. Where was I. The 550 Suzuki has run fine for ages. Its a bit of a mongrel engine/bike. But does work well. During the last 6 months it started to foul the center plug. Black and oily. Put in a new plug and all is well for maybe 3/4 weeks and then the same thing. Always fouls before the engine gets warm/hot.

So whats changed?. Well a while ago, maybe 7/8 months ago I swapped the points for the accent electronic ignition. I put the points on another 550 and moved its electronic ignition to the mongrel bike. The bike with the points actually seems to run better. The bike with the elec ignition seemed to be ok to start with. They are both running with B8ES plugs.

Sometimes the mongrel bike will only manage less than a 100 miles before the center plug fouls. I switched the coils on the mongrel for a set that worked fine on the 750L. It seems to do better. I made up a set of brand new coils/plug caps (rex speed shop) to try but was advised that the new coils might not be "rated" for the accent ignition so I put them on the 750L (points only) and they seem to work well.

So...... I am wondering if the accent ignition really does need the right grade of plug, or it will find an issue with some of these old coils.
I do like to 'pootle' about down the country roads but there is a good stretch of road on the way home to get a move on.
Its surprising how different these 550's can feel with the Accent ignition.

OB

[Alan H]

All my Suzukis have (or had before being sold) points. They work fine. Electronic ignition on modern bikes that rev higher or vehicles that the owner doesn't understand how to maintain are fine, but I prefer old school. It works and will always get you home as it ALL doesn't fail, unlike electronic ignition.

Anyway, I always use non resistor plug caps (resistor plug caps are about 5000 ohms, so the 'spark' has to work a bit harder to get to the plug and is a bit weaker) and non resistor plugs (no 'R' in the number on the plug). You should have resistor caps on electronic ignition though.
I reckon you have either a weak spark on the centre plug, or the centre pot is running cooler. That's why the centre carb is jetted differently to the outers. Make sure the plug caps are ok (nip a quarter inch off the lead after the caps are removed - check resistance of the cap from plug side to ht lead side and replace if high resistance - and make sure the centre points wire to the coils doesn't have a sh1tty connection hidden under the rubber shroud behind the left rear of the air filter.
If you still have issues with plug fouling, either use a bit more throttle - this will give all other road users the benefit of that lovely smoke too - or swap centre and one of the outer plugs if it starts to play up.
Just a thought, what 2 stroke oil do you use, and is the pump set correctly? You can lean this off a tad if you use semi synthetic 2t oil.
Another thought (don't knock 'em, I have less nowadays and like to share the few that still come through!) I wonder if the SRIS valve under the centre crankcase is blocked? This wouldn't allow excess oil that builds up when running slower to be recycled properly so when you do give it beans, it just fouls the centre plug.

[canaletto5]

Right.... a bit side tracked by a 4 cylinder Honda. Where was I. The 550 Suzuki has run fine for ages. Its a bit of a mongrel engine/bike. But does work well. During the last 6 months it started to foul the center plug. Black and oily. Put in a new plug and all is well for maybe 3/4 weeks and then the same thing. Always fouls before the engine gets warm/hot.

So whats changed?. Well a while ago, maybe 7/8 months ago I swapped the points for the accent electronic ignition. I put the points on another 550 and moved its electronic ignition to the mongrel bike. The bike with the points actually seems to run better. The bike with the elec ignition seemed to be ok to start with. They are both running with B8ES plugs.

Sometimes the mongrel bike will only manage less than a 100 miles before the center plug fouls. I switched the coils on the mongrel for a set that worked fine on the 750L. It seems to do better. I made up a set of brand new coils/plug caps (rex speed shop) to try but was advised that the new coils might not be "rated" for the accent ignition so I put them on the 750L (points only) and they seem to work well.

So...... I am wondering if the accent ignition really does need the right grade of plug, or it will find an issue with some of these old coils.
I do like to 'pootle' about down the country roads but there is a good stretch of road on the way home to get a move on.
Its surprising how different these 550's can feel with the Accent ignition.

OB

It may be you are running rich on that pot. check the air setting first by leaning it out a quarter turn at a time and see if it makes a difference. Otherwise, it could be the float level is out and over-fueling the pot. Kev