spark plug indexing?

[Josh]

Do to the configuration of the 2 valve head on our "beloved" machines, would there be any benefits of indexing our spark plugs(mine aren't the same). Anybody have any suggestions or theories on this subject? I'm sure the advantages aren't much but it surely can't hurt!

[DeBenGuzzi]

Do to the configuration of the 2 valve head on our "beloved" machines, would there be any benefits of indexing our spark plugs(mine aren't the same). Anybody have any suggestions or theories on this subject? I'm sure the advantages aren't much but it surely can't hurt!

well, how much money do you have? dual plugs isn't needed. gains are unknown

[Josh]

well, how much money do you have? dual plugs isn't needed. gains are unknown

 

I'm not talking about dual plugging. Indexing is when you install auxiliary washers of varying thickness under the spark plug's shoulder so that when the spark plug is tightened, the gap will point in the desired direction(I'm just not sure what direction this would be). I think a set of indexing washers would cost less than $10.

[Guest ratchethack]

Josh, I posted a query on this a couple o' years ago. I had remembered way back in the heyday of hemi-head pushrod motors , when an old racer's trick was to index plugs. I'd been getting a consistent soot shadow on one side o' my plugs. Pete Roper replied with a comment to the effect that having a good expunging of the anal pore prior to riding would have more benefit. I reckon he's right.

[Josh]

Josh, I posted a query on this a couple o' years ago. I had remembered way back in the heyday of hemi-head pushrod motors , when an old racer's trick was to index plugs. I'd been getting a consistent soot shadow on one side o' my plugs. Pete Roper replied with a comment to the effect that having a good expunging of the anal pore prior to riding would have more benefit. I reckon he's right.

 

Gotcha!

[DeBenGuzzi]

never eard of indexing and thoght you must have meant dual plugs

 

yup, learn something new everyday

[pete roper]

I saw this asked on one of the other boards (WG.) and hoped that someone else would respond. Honestly. You'll never notice a shred of difference.

 

This is another of those questions that prompts me to ask "How much time and money have you spent on your suspension?". No, I'm not tyring to be smart but it is usually the way that people try and do stuff, the cheaper the better, to their engines in the hope that it will make 'em go faster but they completely overlook chassis set-up and this will pay HUGE dividends instantly and usually a very low cost. Most motorbikes nowadays come with pretty good, and fully adjustable, suspension components as standard but few people actually try adjusting them from the factory settings and even fewer make adjustments year round to account for changes bought about to things like oil viscosity by ambient temperature changes! If you think I'm kidding I'm not, since the temperature is going up here I'm winding up the damping on the 'G' to compensate, on cooler days I'll wind it off a little bit if I plan to ride hard, it only takes a second or two and makes a difference far greater than indexing plugs ever would to the performance of the bike.

 

Pete

[DeBenGuzzi]

I saw this asked on one of the other boards (WG.) and hoped that someone else would respond. Honestly. You'll never notice a shred of difference.

 

This is another of those questions that prompts me to ask "How much time and money have you spent on your suspension?". No, I'm not tyring to be smart but it is usually the way that people try and do stuff, the cheaper the better, to their engines in the hope that it will make 'em go faster but they completely overlook chassis set-up and this will pay HUGE dividends instantly and usually a very low cost. Most motorbikes nowadays come with pretty good, and fully adjustable, suspension components as standard but few people actually try adjusting them from the factory settings and even fewer make adjustments year round to account for changes bought about to things like oil viscosity by ambient temperature changes! If you think I'm kidding I'm not, since the temperature is going up here I'm winding up the damping on the 'G' to compensate, on cooler days I'll wind it off a little bit if I plan to ride hard, it only takes a second or two and makes a difference far greater than indexing plugs ever would to the performance of the bike.

 

Pete

how, um would I go about adjusting said settings? I mean I can't really ride around with a screw driver and click it on the fly, ....or can I no no I can't

[pete roper]

how, um would I go about adjusting said settings? I mean I can't really ride around with a screw driver and click it on the fly, ....or can I no no I can't

 

No, not while you're actually riding but if you ride and it feels a bit squidgy you stop, get the screwdriver out and adjust. Works for me. I suppose some forks will be different/harder to adjust and of course spring rates are more difficult, especially with the V11's cantilever rear shock, I believe that some of the Marzochhis also have the compression in one leg and rebound in the other so you have to fiddle independently with either leg but it's not difficult and surely anyone can carry a small screwdriver somewhere on their bike?

 

Pete

[emry]

Since I have Ohlin's i actually have a small allen key taped to the inside of my wind screen. Pull into a gas station and fiddle....

[Guest Nigelstephens]

I'm interested in the original post too.

 

I have a dark shadow on one plug but not the other. I know that one cylinder runs cooler than the other. Could this be part of an explanation? other than fuel pressure/injector difference.

[pete roper]

I'm interested in the original post too.

 

I have a dark shadow on one plug but not the other. I know that one cylinder runs cooler than the other. Could this be part of an explanation? other than fuel pressure/injector difference.

 

Nah, I don't think so. What year is your bike? If it has a lambda sensor in only one pipe that might be an explanation, otherwise it's more likely to be TB ballance or simply a result of the firing intervals. The Guzzi, and most other, 90* Vtwins with a shared crankpin have firing intervals of 270*/450 degrees. That's what gives them the loping exhaust note, but it also means there is a *lazy* cylinder. Back in the late '80's early '90's there were even some models built for the Kaliforni-a market that had diffeenetially sized pilot jets to try and keep the emissions down when running on the slide. ell it seemed to work 'cos they got through. Sounds well shonky to me Most carburetted twins will run one plug significantly darker than the other, (the left from memory ) due to the 'Lazy' nature of the cylinder.

 

Pete

[Dan M]

I saw this asked on one of the other boards (WG.) and hoped that someone else would respond. Honestly. You'll never notice a shred of difference.

 

This is another of those questions that prompts me to ask "How much time and money have you spent on your suspension?". No, I'm not tyring to be smart but it is usually the way that people try and do stuff, the cheaper the better, to their engines in the hope that it will make 'em go faster but they completely overlook chassis set-up and this will pay HUGE dividends instantly and usually a very low cost. Most motorbikes nowadays come with pretty good, and fully adjustable, suspension components as standard but few people actually try adjusting them from the factory settings and even fewer make adjustments year round to account for changes bought about to things like oil viscosity by ambient temperature changes! If you think I'm kidding I'm not, since the temperature is going up here I'm winding up the damping on the 'G' to compensate, on cooler days I'll wind it off a little bit if I plan to ride hard, it only takes a second or two and makes a difference far greater than indexing plugs ever would to the performance of the bike.

 

Pete

 

 

What Pete said.

[Josh]

Nah, I don't think so. What year is your bike? If it has a lambda sensor in only one pipe that might be an explanation, otherwise it's more likely to be TB ballance or simply a result of the firing intervals. The Guzzi, and most other, 90* Vtwins with a shared crankpin have firing intervals of 270*/450 degrees. That's what gives them the loping exhaust note, but it also means there is a *lazy* cylinder. Back in the late '80's early '90's there were even some models built for the Kaliforni-a market that had diffeenetially sized pilot jets to try and keep the emissions down when running on the slide. ell it seemed to work 'cos they got through. Sounds well shonky to me Most carburetted twins will run one plug significantly darker than the other, (the left from memory ) due to the 'Lazy' nature of the cylinder.

 

Pete

 

I've noticed the darker plug also. This is why I asked the question about plug indexing!

Some time back I purchased a colortune (a spark plug with a window so you can see the color of burn in the combustion chamber) and noticed that the left cylinder actually runs a little richer than the left. The carbs have been balanced with a twin max, air filter pods cleaned and valves also have just been adjusted. The firing interval must be why I'm seeing the difference, thanks for the explanation Pete.

By the way this colortune spark plug is a cool little tool, I really like it.

[luhbo]

Lazy cylinders? Are there busy ones, too? Quite a pitoresque explanation. Most people don't like such pictures or art in general when they become too challenging. Are they made up here they seem to flush down right into anybodies mind quite confortably.

 

In the ECU you have a so called offset map to deal with such things. BTW, I don't use it and my spark plugs are looking quite equaly to one another.

 

Besides one cylinder being lazy you can find other, maybe better measurable differences on your bike as well, be they different exhaust lenghts, intake lenghts, different intake angles, flap opening relative to intake direction, or, last but not least, different snorkel postions in the airbox.

 

What I don't see actually is the idea behind the indexing. Just because Pete thinks it's bullshit doesn't automatically make it become such, does it?

 

Hubert