I missed you too Lou... I used air quotes for "Go Faster"

 

^^^^^Aw Joe - It's GREAT to have you back - FULL TIME

Lou

 

Joe Z

 

Speaking of that Joe, where did you disappear to for a couple years it seemed like?

 

He got busy with life. Happens to the best of us from time to time.

 

Thanks JoeZ. I have an inquiry in to my online manual supplier as to where exactly they got their spec. I will say this, the engine is definitely a little peppier. But 1.1mm it is. Done. Settled. Finis. Engine even sounds a little different. I may pull them and regap to 1.1 just to make it right. Depends how bored I get.

 

Since we have all the right subject matter experts in this thread...

I was curious to understand how the spark plugs found in the RC F / GS F / LC 500, may or may not work correctly with our IS F..?? 2UR-GSE platform

19100P SPARK PLUG
Part # 90919-01279 / FK20HBR-J8
Gap = 0.031 in. / 0.8 mm


The IGNITION COIL ASSY, part # 90919-02260 are identical in all these applications.


Below is some of the Yamaha Motor Tecnical Review data during development of updated 2UR-GSE.





Joe Z

 

Higher compression engine, smaller plug gap. That's pretty normal.

 

Yep. Might be a colder plug too. Not sure.

 

No. They're both 20's. The heat range is the number right after the size code.

https://www.denso.com/global/en/prod...ies/plug/type/

 

I just bought those plugs and the were pregapped to .032". Just sayin.

 

If you bought FK20HBR11 plugs and they measured 0.032", they were damaged or counterfeit. The 11 at the end means 1.1mm gap from the factory.

 

Hello guys, this is very good thread to discuss.

So I have GS-F and I change pistons compression from 12.3 to 10.0 forged to be prepared for the SC roots kit.

But for now I will use and tune the car for NA

So my question is, dropping the compression from 12.3 to 10.0

What gap should I set mine at ?
I will use heat range 6 from NGK

But what gap do you recommend ?

Stock GS-F gap .031 ( 12.3 compression )
Stock IS-F gap .038 ( 11.8 compression )


So my engine now is at 10.0 compression

All opinions are welcome and thanks for the support

 

Without boost, the factory plugs will work fine. After boost, especially starting at 10:1, you'll likely need to change heat range and gap to suit the new conditions.

 

So you recommend to use .031 on 10.0:1 compression ?

Also iridium or ruthenium hx ?