Spark plug after 50k kilometers

[scoot_to_boot 154]

Hi all,
haven't posted in a while. As my Integra has done about 98k kms now I was going to replace the plugs again as per the manual. There is no visible erosion at all.  Using a feeler gauge, the clearing is ca. .93 for the used plug vs. .98 for the new one. Tolerance is 1.2 mm. Given the Iridiums are crazy expensive, I just wanted to warn against ordering them without having check the state beforehand. Pulling the center fairing panel isn't even that painful.

I will probably stick the new ones in anyway. If I dont change them now, I somehow doubt I will ever get to use them .... 

 

[steeve139 98]

Hi,

 

I have long suspected that spark plug gap and swap advice has more to do with history than it does to today's engines, ignition systems, and fuel injection.  Imagine an engine where spark timing is determined by switching points on a cam, the build up of HT voltage in a large central coil, and the spark plug and distributor cap gaps.  Imagine an engine where the fuel-air mix is managed by a finely balanced mechanical assembly, where the exhaust isn't monitored, so the fuelling mix is open loop.  They were all like that!  It was a miracle they worked as well as they did.  We kept them going by adjusting and cleaning the plugs, checking and adjusting the points, and by fiddling with the carbs. 

 

Nowadays, liquid cooling controls the temperatures within a narrow range, electronic ignition makes a spark exactly when required, and fuel injection provides just the right amount of fuel.  But the old spark plug advice still lurks in documentation.  What should we do about it?

 

If you are paying someone to service your bike - let them do it according to the book.  Including checking, gapping, and replacing the plugs - whether necessary or not

 

If you are servicing your own bike, then you will be saving lots of money, and all your spend will be on materials.  Whether you buy plugs or not, you will still be saving lots of money.  If you take your existing plugs out to look at them, you may as well pop the new ones in.  If you are wondering whether to buy new plugs, you probably don't need them, and you can double the service interval (for the plugs) compared to what is stated in the book.

 

What am I going to do?  Let the dealer do the 8k and 16k services, including whatever the book says about the plugs.  Thereafter I will do the 24k and 32k services myself.  At the 32k service I will put new plugs in regardless of the condition of the existing ones.  I will keep the "old" plugs for back-up purposes. 

[Xactly 5,441]

It can be a real money spinner for franchised dealers. Moto-Guzzi specifies a ludicrous 6,000 change (not inspect) interval on my V7 850 Special. Whilst it lacks the stable operating temperature of a liquid-cooled motor, there is no justification that I can see for replacement at such low mileage. The plugs themselves are very easy to access for inspection. I shall replace mine when and if they need it, servicing the bike myself now anyway, irrespective of warranty.

[steeve139 98]

There is a lot to like about the Moto Guzzi V7 special, from the petrol tank size, plenty of power, and shaft drive.  I see some bargains on autotrader-bikes at the moment in April.  Easy access to the spark plugs - wonderful.  Being able to take the valve covers off without touching the petrol tank - almost unique (English teachers please forgive me).  I wish more bikes had those attributes.

 

I can't believe that the V7 engine will wear out spark plugs much quicker than a car engine.  Keep a new pair of plugs at home, and just inspect yours every 6000 miles.  Photographing them sounds like a good plan.

 

I wish there was someone like Gutsibits for our Hondas.

[Scootabout 2,265]

1 hour ago, Xactly said:

It can be a real money spinner for franchised dealers. Moto-Guzzi specifies a ludicrous 6,000 change (not inspect) interval on my V7 850 Special. Whilst it lacks the stable operating temperature of a liquid-cooled motor, there is no justification that I can see for replacement at such low mileage. The plugs themselves are very easy to access for inspection. I shall replace mine when and if they need it, servicing the bike myself now anyway, irrespective of warranty.

Replace every 6k? On the V85TT it's 18k (30k km). But yes, the plugs ain't cheap. I've just had them done. £67.94 for the pair, including VAT! It turned out to be an expensive service, but then it included a remap which seems to have cured my pinking problem, so I'm not complaining.     

[Andy m 23,599]

At the risk of repeating myself again 😁😁, why do people still think the manufacturers set service requirements based on longevity of function?

 

Would McDonald's tell you to only eat their McSuggary desert in preparation for running a marathon or an attempt at human powered flight?

Do ABTA not recommend flights to Spain in August to Gingers?

Would Turkey's point out that a mid winter festival might cheer us all up a bit?

 

Service intervals set by sellers of oil are based on what the market will stand. Where hire car and van users switch brand they get longer. Where the owners love any excuse to pamper their baby they get shorter.

 

Moto Guzzi aren't good at this game.

 

Andy

Edited April 27, 2023 by Andy m

[Xactly 5,441]

11 hours ago, Scootabout said:

Replace every 6k? On the V85TT it's 18k (30k km). But yes, the plugs ain't cheap. I've just had them done. £67.94 for the pair, including VAT! It turned out to be an expensive service, but then it included a remap which seems to have cured my pinking problem, so I'm not complaining.     

Why should a remap make it an expensive service? I’ve done this myself - I’m sure the technician just connects it up, starts the remap then either gets on with something else on your bike or another. It takes minutes of actual work. It should be free anyway if it corrects the rubbish original map. (Two V7 850 remaps so far, neither of which mine has because I did an aftermarket one myself). I have no intention of replacing the plugs on my V7 at 6,000 miles - I’ll do it when they need replacing. I service mine annually before laying it up for winter. The plugs looked unused last November when I checked them.

[Xactly 5,441]

12 hours ago, steeve139 said:

 

 

I wish there was someone like Gutsibits for our Hondas.

David Silver is the UK Honda equivalent for older Hondas. Fowlers is a good one for modern Hondas. I find Gutsibits caters more for older Guzzis than the current range.

[Andy m 23,599]

Wemoto and Fowlers for me. Gutsibits and David Silver for more specialist stuff. I used to get old Honda parts from CMSL in the Netherlands, a better selection available than Silver's.

 

I once charged a bus company £520.16 to change a fuse. They said warranty and behaved like spoilt toddlers, I proved it wasn't. What work costs is down to investment in knowledge and equipment. An ECU flash looks like witchcraft so can be charged accordingly. Can also be a ****- off quote if the tech isn't confident he won't brick the electronic.

 

The service light annoys me more, wrong symbol, should be "$£$".

 

Andy

[Xactly 5,441]

I haven’t yet seen the little orange spanner on mine. It seems to be mileage related only. ie it doesn’t light on the anniversary of the last service where, like mine, the annual mileage is low. Good.

[Andy m 23,599]

Yes, mileage related. Serviced at 898 by the Moto Corsa idiots, came on at 999 😩😠

 

Andy

[Xactly 5,441]

Mine had exactly 500 miles on it when I bought it. I had it serviced when it had done 900 miles. The light never lit. I presume therefore that the first default is 999 miles. There is reference in the owner’s handbook to the first service being the exception to the light coming on. I assume therefore that this means if the service is done around the specified 900 miles it won’t show the indicator, but if left to 999 miles it will (unless as in your case the real spanners are the technicians who failed to reset it when the service was carried out within schedule)…..Might be a while until mine lights up then.

[Slowboy 20,540]

2 hours ago, Andy m said:

Yes, mileage related. Serviced at 898 by the Moto Corsa idiots, came on at 999 😩😠

 

Andy

Same on the Enfield, just a mileage counter. 😂😂😈

[Rev Ken 6,343]

Iridium plugs must have got a lot more expensive than when I bought them! I've fitted them to three of my bikes and then just 'forgot' them. My CBF1000 (which my son has inherited') has now done over 40,000 miles and still starts more easily than when I first had the bike with 'normal' plugs.

[shiggsy 529]

Honda sell them for double the price you can buy them elsewhere,  I wanted to buy them at the parts desk of a Honda dealer and they told me not to get them there because they were so expensive.

[Scootabout 2,265]

13 hours ago, Xactly said:

Why should a remap make it an expensive service? I’ve done this myself - I’m sure the technician just connects it up, starts the remap then either gets on with something else on your bike or another. It takes minutes of actual work. It should be free anyway if it corrects the rubbish original map. (Two V7 850 remaps so far, neither of which mine has because I did an aftermarket one myself). I have no intention of replacing the plugs on my V7 at 6,000 miles - I’ll do it when they need replacing. I service mine annually before laying it up for winter. The plugs looked unused last November when I checked them.

It wasn't an expensive service because of the remap. That was part of the 2 hour labour charge, I assume, since it wasn't itemised and charged separately. It was expensive because it was a major service, including plugs and changing the transmission and gear oils, as well as the usual stuff, and at central London labour rates.  I was happy, despite the cost, because a worrying issue has been fixed as part of the package. Especially since I'd been thinking I'd need to spend £120-150 on a booster plug or Rapidbike Easy. 

[steeve139 98]

Hi,

 

I just did my Forza 16k service myself - after learning the dealer would charge me £550.  And at 16k I didn't look at the spark plugs - I just left them in, to carry on the good work they are doing.  At the moment I am planning to pull the plugs as part of the 24k service - but who knows what I will be thinking when the time comes?  It is a moving feast.  Surely I will be taking them out at 24k or 32k.........

[Slowboy 20,540]

2 hours ago, steeve139 said:

Hi,

 

I just did my Forza 16k service myself - after learning the dealer would charge me £550.  And at 16k I didn't look at the spark plugs - I just left them in, to carry on the good work they are doing.  At the moment I am planning to pull the plugs as part of the 24k service - but who knows what I will be thinking when the time comes?  It is a moving feast.  Surely I will be taking them out at 24k or 32k.........

If they’re still iridium plugs like they were on my NC700x back in the day I’d be suprised if they ever need changing. My were still doing their stuff after 52,000 miles and were still in spec for the gap.