..motorio 48mm kitting..

[wordslinger]

..put a kiit on that bitch!..

 

..well, i'm finally going to upgrade one of my ppls to a 48mm, 72cc....

..piston, rings, head, cylinder, pipe, filter...never attempted this before, ssso.......

..i have a question ...anybody got a suggestion of what my main jet should work out to be?

..this issa 2001, and has the big carb, same as S9lc except for coolant ports..


peace

[Areomyst]

Congrats sir.

FYI 48mm is going to be bigger than 72cc.   It's 74.9cc. 

Do you have a link to the kit you're using?  I haven't tried it before.

If you're going to use the stock carburetor, I'd keep the OEM filter - it's easier to dial in.  You need to shim the needle with the open filter, and it can be kind of a pain.  At least, that's my experience.  I usually do the PHBG anyway.  That said, using the stock filter you'll probably be in the 90-100 area on the main jet.  The last time I did a setup with a stock carb, I think I was somewhere around 94 on the main, but I can't remember for sure...  It's best to jet rich, and go down one size at a time until it stops sputtering at WOT, then start doing plug chops.

Keep us posted.

~Josh

[wordslinger]

FYI 48mm is going to be bigger than 72cc.   It's 74.9cc.  

Do you have a link to the kit you're using?  I haven't tried it before.

..well, thats even better!..

..i got it from mhr-usa.com, in their "specials" section, but i have not looked for the motorio link yet..good idea!..

..batman turned me on to it, he got same thing for his zx, i believe..

..thanx for the oem airbox tip..easier is better for me, as i burned the oem piston and trashed the cylinder..

..i've had crap for luck in my 2t experience..got 74,000kms on my a50, but i've burned 2 2t pistons, whn i would have sworn on the plug chops...

..thanx for the info josh!

[zombie]

With an open filter I was running 150ish main, and 48 pilot.(47mm kit) I never tried w/ a stock filter but 90 may even be too low depending on the pipe. If you get a jet kit start at 90, and get them thru to 130. Like Aero says start rich, and work down. Also DONT try to get the jetting on the first run. Get the idle/mid range first. Break it in fir 2-3 days running on those circuits only. Then start creeping it up. I dont really believe in extended break in but w/ the cheap sh*t pistons they are providing it is almost mandatory to dial them in perfectly from the start. You'll be a scream'in demon in a week. Order xtra head gaskets too. at least 3. You can run it w/ 2 or more to break it in.

[wordslinger]

With an open filter I was running 150ish main, and 48 pilot.(47mm kit)

..woww...


You can run it w/ 2 or more to break it in.

..what do you mean by this?..

[zombie]

Double up the head gaskets to lower compression. The Motrino kit is the Ruima kit. It does NOT have a squish band. It is a controlled combustion design made to run higher compression, and avoid pre-ignition. The problem is it is more sensitive to lean conditions, as it will try to PLOW thru, and you will have another piston for your desk. Once you have the jetting/break in done remove the extra gaskets, and enjoy. I see another Sid thread comming... 40 pages.

[wordslinger]

The Motrino kit is the Ruima kit

..i did not know that..no wonder my googling was coming up short..

I see another Sid thread comming... 40 pages.

..lmao..yeah, this is going to be FUN!!

 

[zombie]

That's why we do it RIGHT! Most important thing is to chamfer/de-burr/measure EVERYTHING. Don't trust the Manuf. to do it. And add guide pins between the head, and Cyl. as there are none. A misaligned head will give you a squish band on the first start up.

[wordslinger]

Most important thing is to chamfer/de-burr/measure EVERYTHING. Don't trust the Manuf. to do it. And add guide pins between the head, and Cyl. as there are none. A misaligned head will give you a squish band on the first start up.

..awesome!..thanx z...imma complete newbie...don't know a damned thing...

..hows best way to install guide pins?

[zombie]

I bought a set of them at Ace Hardware for 4.50. They are made for Chevy 350ci engine heads. Find a drill bit that is a tight fit for the pins in a test hole in a piece of scrap metal. Then just drill into 2 of the holes for the cylinder studs, and the same for the head. They are called Guide Dowels (really just hollow tubes made from case hardened steel) http://www.summitracing.com/search/Part-Type/Cylinder-Head-Dowel-Pins/

[wordslinger]

..okay.."roll pins"..."spring pins".. i gots that stuff already...

..nuther ?..what plug would be right for this 48mm?

[wordslinger]

..just checked that link..not really spring pins..


 

[zombie]

Depends on tooo many things...Lean, Rich, Humidity, ect. They will ship you an NGK BR8HSA if you ask for their recommendation. I am using a BR9HSA. Slightly colder, and am looking for a 10 so I can lower my jug, and raise the timings. The 9 runs real well when it warms up. The 8 would ping a little at WOT. W/ a stock filter tho you may run better on a 7 getting more heat to burn a richer mix. ORRRRRRR you could try a BR8HS. Same heat range just all tucked up into the head instead of being in the flash zone. You will loose a few rpm.s but gain a few cc's(.5-1.5), and jetting will be better tolerated cause the flame front has to start at the top, and go in one direction DOWN. W/ an extended tip the flame travels in all directions making detonation more likely. It's all a balancing act Bro!

[zombie]

Spring pinns will work if you can find one thin walled enough for the studs to fit thru. You will have to cut them to length tho.

[wordslinger]

...okay cool..trial end error, and i have those plugs already, except for th 7s...

..my buds oem zx runs like crap with th brhs...put in a hsa and it smooths right out..

..thanx for all the info, z....i gotta roll outta here..

..be back on sometime tomorrow...


peace