I meant I didn't want to challenge his opinion because I know hes one of the engine experts out there, I just wanted to share my opinion.

Understood

Don't let these guys worry you dude...there is no power loss or other hidden issues running that OS plug........... I myself prefer running the Nova plug of course........ but I have seen too many guys run the OS plug successfully for me to write it off.....So instead the last couple of weeks out I myself tested the different plugs back to back.....Testing the idle quality, performance. tuning etc...... and we seen no decrease in output whatsoever... We did see a slight loss of mileage with the OS plugs, but the engines did have a stronger idle and were much more forgiving to tune...definitely less prone to flameouts if the tune was off...... We also put OS plug back to back with Nova plug int he same buttons and had zero issue with them sealing................Tho I do know others have had issues with this, I have not seen it yet here......Worse case you need to buy a new button, we will hook you up at a good price if needed....So carry on and don't worry what anyone says !!!

Holy crap this thread got off track. For 3 yrs i ran vzb speeds. I love those engines. The new xzb speeds are in my opinion one of if not the strongest stock engines. I have seen the xzb blue head run well also. If i had my choice out of all for a buggy it would be the vzb based engine. So if the hara runs like the older speed then snatch it up. If i remember the difference, the hara didn't have a slugged crank. Is that correct?

Which glowplug would work best if I wanted to spray brake clean at my front bearing all day? Thanx in advance.....

The only reason you would be spraying brake cleaner at your front bearing is to see if its bad..............

you guys saying you cannot run OS plugs in Nova engines are simply mistaken......there is absolutely no issue running a OS plug in the Nova engines that I can see....Right now we have about a dozen Nova's running perfect on OS plugs.... many of them have swapped back and forth between OS and Nova plugs and had zero issues...no stripped threads, no damaged button, no metal particles.... nothing.....All the talk on the internet you would think there would be damage or some other issue with at least one engine.., but the reality is there is no issue and not one of the engines leaked when put back to Nova plugs.......So everyone saying you cannot run OS plugs in a Nova is WRONG ! you obviously can run a OS in a Nova and there doesn't seem to be any negative issue caused from it.... there is no power loss ( this one kills me LOL ) , there is no tuning issue, no metal shaving, no leaking button...just a stronger idle and broader tuning window.......

I am n ot even the one who started this..it was brought to my attention by several people, so I decided it was worth investigating..... So I Spent time and tested the OS plugs myself out of curiosity and found they work quite well.........Myself I cant say I have any issues with Nova or Werks plug, and I generally recommend people use those plugs in a Nova......But I cant ignore the excellent results some of the guys are having with the OS plugs.....

I know running OS plugs in a Nova is not right, but I cant argue with what is working well right in front of my eyes.....

I will maybe shoot video of going back and forth betwen plugs and show there is no issues caused......

The neww XZB hara comes without a slug very good mill great on gas its butter like smooth. Ive had my play with these Speeds new and old "version". I will say this thou the new speeds dont have the pinch from prior some need a pinch sooner then others as you stated GREAT mills to run, Great carbs actually perfer over Nova Long needle if I may add but I like my CRE mills TOOOO

Is there any DLC coated crankshaft that fits on OS xz-b engine (blue head) ?
Does os xz-b speed's crankshaft fits on then xz-b blue head ?

All the .21 XZ/XZ-rebadged crankshafts are interchangable (Hara, Speed, B02, Bullit, LRP/NOSRAM, SWorkz, etc,). Keep in mind that some have timing differences too.

Which DLC crankshaft will suit my xz-b blue.
xz-b Speed's crankshaft will be suitable ?

All of them work. Ninja B02 is probably closest performance wise to the blue head XZ.

So if I were to put my bo2 crank/piston/rod into my blue head xzb would it work fine?

2nd ? Is the pin that goes threw the piston on the bo2/speed dlc coated also?

3rd ? Lol. The 19s crank is smaller then the 21 cranks right? Also what's the head shimming on the 19s? I only have 1 silver shim in mine n i havnt run it yet.

That's correct. I don't know what style head button the B02 uses, but it shouldn't matter, because shimming is the same regardless.

It is not DLC coated. It's a typical 4mm wrist pin... I don't remember length. Maybe ~14mm?

Completely different. The .21 is 14mm diameter and .19 is 12mm.