Spark Plug Change - Remove tip or not? - Need help

[idle363]

Hi all, I haven't seen this mentioned here before so I thought I'd ask. I'm getting conflicting information between the dealership and the service manual from Rotax. I have a 2017 Scarab 195 with the 250hp Rotax 4-tec motor (purchased the boat used last year). I went to change the plugs for the first time and when I pulled the old plugs, I noticed they had a small threaded tip (about 3/16"dia.) rather than the pear-shaped tip I'm used to seeing on a spark plug. At first I assumed it was broken, but after some research, I learned that NGK does in fact make plugs with this style tip (news to me).

Here's the confusing part... The Rotax manual specs the NGK DCPR8E, and that plug happens to be a "Loose" style, meaning it has a removable tip to reveal the smaller threaded stud. However no where in the service manual does it say to remove the tip before installing, and it shows pictures with the tip still intact. I called the dealership I bought it from and the service manager says, "yes, on the Rotax engine it's easier to install the ignition coil if you remove the spark plug tip."

Is this really how it should be done?, or is he just saying it's "easier". It would make sense that my old plugs had the tip removed if he was the person who last serviced it. But it did only have 70 hours on it when I bought it, so it's also likely that those plugs were installed from the factory.

Not sure what to think here! Can anyone help? Obviously I'd like to run the plugs like the factory would suggest.
Side note, I contacted BRP (Rotax) and they can't answer me either! They only tell me to contact the dealer. Seriously!?

 

[Dean P]

I changed my plugs couple months ago. I noticed that too! But, if you do not unscrew the cap you cannot put the plug back on. Only one of the spark plug caps twisted off without the use of a pair of pliers. Once they break free (hardly any effort) they unscrew very easy; piece of cake. With that cap removed, you'll feel the plug actually click on like it supposed too.

 

[Dean P]

Oh, to the forum! Lots of good info here. Post pics when you can. We love people having fun on their boat.

 

[geierb387]

The small cap needs to be removed. All Rotax 4-stroke motors use this same method. The plug will not 'click on' with the tip installed.

 

[BobJohnson]

WOW- I’ve been changing my plugs each year (2015 boat) and always felt the coil didn’t sit right on the plugs. I thought I’ve read and seen every post/topic on our engines and never saw this. Never thought I would need to modify my plugs other than ensure gap. My boats still in storage but I’ve got some old plugs here at home that I am going to go check out.

 

[ScarabRyan]

I need to change my plugs for the first time on my boat with 67 hours on it. I just purchased 3 weeks ago and the third time we took it out I got a rough idle and check engine light came on. The dealer it was originally purchased from is 2 hours away and they are the only one that said they will service it.
My local marine max said since I didn’t buy it from them they wouldn’t service it even though they are the scarab dealer in LEWISVILLE, TX. Which I thought was pretty dumb they just turn away business. Anyways, mine is a 2015 195 HO, is the plug I need the same one idle363 mentioned, the NGK DCPR8E ? I have scoured the internet and even read my owners manual and it doesn’t have the part number.

 

[ScarabRyan]

I believe it is the plugs because of the hours and symptoms. And the dealer north Texas marine that has serviced it told me it was 90% chance that it was the plugs.

I need to change my plugs for the first time on my boat with 67 hours on it. I just purchased 3 weeks ago and the third time we took it out I got a rough idle and check engine light came on. The dealer it was originally purchased from is 2 hours away and they are the only one that said they will service it.
My local marine max said since I didn’t buy it from them they wouldn’t service it even though they are the scarab dealer in LEWISVILLE, TX. Which I thought was pretty dumb they just turn away business. Anyways, mine is a 2015 195 HO, is the plug I need the same one idle363 mentioned, the NGK DCPR8E ? I have scoured the internet and even read my owners manual and it doesn’t have the part number.

 

[BobJohnson]

@ScarabRyan Yes. That’s the Spark plug you need.

 

[ScarabRyan]

@BobJohnson Thank you Sir!

 

[ScarabRyan]

What is the correct spark plug gapping for the 2015 HO Motor ?