The Star Venture/Eluder V-Twin uses four spark plugs, two for each cylinder, in order to change them you need to either remove the fuel tank which involves draining the fuel and disconnecting the fuel lines and several electrical connectors giving full open access to reach all four of the spark plugs.
The second method is to remove the two rear fuel tank mounting bolts and lift the rear of the fuel tank and placing a small piece of 2x4 under the rear of the fuel tank, this will give you enough clearance to reach all four of the spark plugs. You can use a piece of small rubber hose that will fit over the end of the spark plug to line up and start the right side front and rear spark plugs in the spark plug holes in the head. Just take a couple of minutes and make sure you don't cross thread them.
Now that you know the two methods to reach the spark plugs to change them, lets talk about the spark plugs, the Yamaha Star Venture/Eluder comes with standard copper core spark plugs, these spark plugs can have a life of between 10,000 miles to 30,000 miles depending on the manufacture, Yamaha specs the standard copper core spark plugs to be changed every 8,000 miles.
You can purchase spark plugs that are designed to last much longer than standard copper core spark plugs, one such plug is the Iridium spark plugs, they have a life span of between 50,000 to 80,000 miles depending on the manufacture.
Copper core spark plugs use a copper center electrode with nickel on the end where the spark jumps to the ground electrode. The reason a copper core spark plug has such a shorter life than platinum or iridium style spark plug is because the end of a copper core spark plug is 2.5 mm wide and as the spark jumps the gap it wears out the edges of the center electrode rounding them off, this causes the ignition system (coils) to have to work harder to produce the same spark.
Since we are talking about iridium spark plugs I will stick to them because there is a direct replacement of the standard copper core spark plug to an iridium spark plug.
The iridium spark plug uses a much smaller head on the center electrode and iridium is the hardest metal used in a spark plug. This smaller head of the center electrode will last far longer than the 2.5 mm head of the center electrode on a standard copper core spark plug. The iridium being a much harder metal also does not wear away like the copper core nickel end center electrode does on the standard copper core plugs. The end result is the ignition system (coils) don't have to work as hard over the life of the plug.
A standard copper core spark plug will start to demand more power from the ignition system to produce the same spark in as few as 4,000 KM (2,485.5 miles) as the plug wears it demands more and more voltage from the ignition system to create the same spark. I will attach a thumb nail from Denso that shows how as the standard spark plug wears it demands more and more voltage to produce that same spark as when the plug was new just to jump the gap of the plug.
Switching over to an iridium spark plug will allow you to double or even triple the life of the spark plug so instead of changing spark plugs every 8,000 miles you can extend that to every 16,000 miles or even 24,000 miles. I have no doubt that an iridium spark plug would even easily go 32,000 miles on these engines.
I have iridium spark plugs in my Yamaha Star Venture and it runs great with them. For those who are interested in the iridium spark plug the direct replacement of the NGK standard spark plug to the NGK iridium spark plug is:
DPR7EIX-9
Stock number 7803, this is a box of four spark plugs.
This is what NGK says about their iridium spark plugs on the box:
The benefits of NGK Iridium Spark Plugs, Lower fuel consumption, Longer life, Smoother idle, Improved ignition efficiency enhancing power and acceleration.
Due to the extended life of these spark plugs they are no more expensive than a standard spark plug in the end and in some cases are actually cheaper depending on how many miles you run them. This is all before the labor charge to change out a set of spark plugs or your own time to change them. Remember that all shops are going to have a minimum labor charge which for most shops is one hour at any where from $80 dollars an hour up to $130 dollars an hour.
As you can see the iridium spark plug turns out to be a bargain in the end.
I have used iridium spark plugs on my 2013 Victory Cross Country Tour air cooled V-Twin, 2016 Harley Davidson Ultra Limited air cooled with heads water cooled V-Twin and now my 2018 Yamaha Star Venture Transcontinental air cooled V-Twin and all three engines from different manufactures have run great with them.
The second method is to remove the two rear fuel tank mounting bolts and lift the rear of the fuel tank and placing a small piece of 2x4 under the rear of the fuel tank, this will give you enough clearance to reach all four of the spark plugs. You can use a piece of small rubber hose that will fit over the end of the spark plug to line up and start the right side front and rear spark plugs in the spark plug holes in the head. Just take a couple of minutes and make sure you don't cross thread them.
Now that you know the two methods to reach the spark plugs to change them, lets talk about the spark plugs, the Yamaha Star Venture/Eluder comes with standard copper core spark plugs, these spark plugs can have a life of between 10,000 miles to 30,000 miles depending on the manufacture, Yamaha specs the standard copper core spark plugs to be changed every 8,000 miles.
You can purchase spark plugs that are designed to last much longer than standard copper core spark plugs, one such plug is the Iridium spark plugs, they have a life span of between 50,000 to 80,000 miles depending on the manufacture.
Copper core spark plugs use a copper center electrode with nickel on the end where the spark jumps to the ground electrode. The reason a copper core spark plug has such a shorter life than platinum or iridium style spark plug is because the end of a copper core spark plug is 2.5 mm wide and as the spark jumps the gap it wears out the edges of the center electrode rounding them off, this causes the ignition system (coils) to have to work harder to produce the same spark.
Since we are talking about iridium spark plugs I will stick to them because there is a direct replacement of the standard copper core spark plug to an iridium spark plug.
The iridium spark plug uses a much smaller head on the center electrode and iridium is the hardest metal used in a spark plug. This smaller head of the center electrode will last far longer than the 2.5 mm head of the center electrode on a standard copper core spark plug. The iridium being a much harder metal also does not wear away like the copper core nickel end center electrode does on the standard copper core plugs. The end result is the ignition system (coils) don't have to work as hard over the life of the plug.
A standard copper core spark plug will start to demand more power from the ignition system to produce the same spark in as few as 4,000 KM (2,485.5 miles) as the plug wears it demands more and more voltage from the ignition system to create the same spark. I will attach a thumb nail from Denso that shows how as the standard spark plug wears it demands more and more voltage to produce that same spark as when the plug was new just to jump the gap of the plug.
Switching over to an iridium spark plug will allow you to double or even triple the life of the spark plug so instead of changing spark plugs every 8,000 miles you can extend that to every 16,000 miles or even 24,000 miles. I have no doubt that an iridium spark plug would even easily go 32,000 miles on these engines.
I have iridium spark plugs in my Yamaha Star Venture and it runs great with them. For those who are interested in the iridium spark plug the direct replacement of the NGK standard spark plug to the NGK iridium spark plug is:
DPR7EIX-9
Stock number 7803, this is a box of four spark plugs.
This is what NGK says about their iridium spark plugs on the box:
The benefits of NGK Iridium Spark Plugs, Lower fuel consumption, Longer life, Smoother idle, Improved ignition efficiency enhancing power and acceleration.
Due to the extended life of these spark plugs they are no more expensive than a standard spark plug in the end and in some cases are actually cheaper depending on how many miles you run them. This is all before the labor charge to change out a set of spark plugs or your own time to change them. Remember that all shops are going to have a minimum labor charge which for most shops is one hour at any where from $80 dollars an hour up to $130 dollars an hour.
As you can see the iridium spark plug turns out to be a bargain in the end.
I have used iridium spark plugs on my 2013 Victory Cross Country Tour air cooled V-Twin, 2016 Harley Davidson Ultra Limited air cooled with heads water cooled V-Twin and now my 2018 Yamaha Star Venture Transcontinental air cooled V-Twin and all three engines from different manufactures have run great with them.