spark plug choice

Bill Wu

New Member
Hello everyone. I'm looking for higer performance spark plug. Could anyone give me advice? Thanks.

Has anyone tried Bosch ZR5TPP33S? Can it fit on RC390? Personally, I prefer to use Bosch Spark Plug though it's hard to get in Taiwan.

Hope someone could give me advice, thx.
 

corners

New Member
Equivalents for the original spark plug are not obvious and you end up matching thread size/depth, heat range and electrode length to find replacements.

The original plug is:

Bosch VR 5 NE

V = M12x1.25
R = resistor
5 = heat range
N = 26.5 mm thread depth, 4mm electrode length
E = electrode material is nickel yttrium

The Bosch ZR5TPP33S looks as if might work.

Not sure if there'll be a noticeable performance advantage of the differences in electrode materials, platinum, iridium etc...

This might offer more information:

Spark Plug Types? - KTM Duke 390 Forum
 
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rideontt

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Use this

Hello everyone. I'm looking for higer performance spark plug. Could anyone give me advice? Thanks.

Has anyone tried Bosch ZR5TPP33S? Can it fit on RC390? Personally, I prefer to use Bosch Spark Plug though it's hard to get in Taiwan.

Hope someone could give me advice, thx.



Have you tried Brisk, its a silver tip electrode. MR12YS is the part no.
 

Bill Wu

New Member
Have you tried Brisk, its a silver tip electrode. MR12YS is the part no.

No, I've never used the Brisk. And there is no one in Taiwan selling the Brisk Spark Plug. In Taiwan, the most popular spark plugs are Denso and NGK. It's very hard to find the other spark plugs...... Even the Bosch ZR5TPP33S. I only found one who sell the Bosch.
 

Bill Wu

New Member
After I tried the Bosch ZR5TPP33S, I found it won't fit RC390. The gap is too long. The piston will hit the sprak plug... Will it cause any problem?
 

Drak

New Member
NGK1406.jpg
Ok time for me to give my two cents. I shall give it for free.
I have tried the following Plugs in my Rc 390: Bosch VR5NE, Pulstar GG1H, NGK 1406. Out of these three the Bosch is ok, the Pulstar quit 4 months in, and the NGK is new.
I picked the 1406 because it was a grade hotter that the Bosch. As the Bosch and the Pulstar were not getting hot enough to preform self cleaning but hot enough not to foul.
I also picked Iridium for its
longevity and disregarded its impedance, as all of the plugs have a resister built in to the plug. So i don't believe that one plug has less resistance than the next.
The last reason i picked this plug is because of the small point that the spark jumps from and the small point the spark jumps to. Forcing it to have a more consistent spark.
Other plugs i looked into are: NGK 93026, NGK LKAR8A-9, and Brisk Silver Racing MR12S. All good candidates. Hope this helps.
 

Bill Wu

New Member
View attachment 2136
Ok time for me to give my two cents. I shall give it for free.
I have tried the following Plugs in my Rc 390: Bosch VR5NE, Pulstar GG1H, NGK 1406. Out of these three the Bosch is ok, the Pulstar quit 4 months in, and the NGK is new.
I picked the 1406 because it was a grade hotter that the Bosch. As the Bosch and the Pulstar were not getting hot enough to preform self cleaning but hot enough not to foul.
I also picked Iridium for its
longevity and disregarded its impedance, as all of the plugs have a resister built in to the plug. So i don't believe that one plug has less resistance than the next.
The last reason i picked this plug is because of the small point that the spark jumps from and the small point the spark jumps to. Forcing it to have a more consistent spark.
Other plugs i looked into are: NGK 93026, NGK LKAR8A-9, and Brisk Silver Racing MR12S. All good candidates. Hope this helps.


Thank you for your suggestion. Now I'm using the NGK LKAR8A-9. It works better than the original Bosch VR5NE. It seems LKAR8A-9 makes engine have more power when it runs at lower RPM after I had drag race with my brother's Ninja 250, I realized that. Equipped with NGK, RC390 can pull Ninja 250 away faster than original Bosch Plug did.
 

RC390-Pig

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There is several videos on YouTube compare Pulstar and NGK, most conclusion is Pulstar the win at square and fair. Interesting to see RC390 perform with Pulstar.
 

ReidMcT

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I'm with Drak so far. NGK 1406, also known as
DILKAR7B11
 

airazen

Member
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i'll go with NGK LKAR8AI-9, more reliable.

i got bad experience using BRISK

uploaded to youtube so you can see them, used less than 1000 KM and imagine if the center electrode falls into the cylinder block...

 

steve77

New Member
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will the NGK 1406 DILKAR7B11 actually fit in a 2018 RC390 ? All searches have said it will not fit - not worth it if its too long and damages something
 
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