I'm wondering if anyone has any experience with the Stage6 MkII Sport Pro 70cc BBK??

I recieved my kit the other day and unfortunately it didn't come with instructions of any real value.
I have done lots of reading on this forum, but would appreciate any advice from someone with firsthand experience with this kit or similar.

I guess I'll just post up my list of questions.

1. Do the piston pin circlips need to be facing a particular direction? Right now I have the little 'arm' that bends in towards the middle pointing towards the top of the piston.

2. Do I need to worry about squish for a daily driver? Should I just go with the thickest gasket and assume I will be safe? What kind of performance am I really losing out on if I don't have optimal squish?

3. What is the torque spec for the cylinder head nuts with this kit?

4. If I am keeping the stock carb and exhaust do I need to change my jets? A rep from the store I bought my kit from said I wouldn't need to change anything unless I changed my exhaust... This seems strange to me.

5. Is the BR9HS plug the right one for this kit? What should the gap be?

6. In the manual for the kit it said that it requires 60:1 mix. Really?? Is that possible with the autolube system?

Sorry for the mile long list of quesitons. I just really want to get this right!

Any help is greatly appreciated.

well considering thats a brand new kit you are proably one of the first

the arrow on the piston needs to face the exhasut
the gap in the circlip needs to be in the direction of travel of the conecting rod(i noramly have the opening towards the conecting rod but it could be 180 deg out from that)
all torque specs are in the service manual
yes you need to worry about your squish you could just go pansy burro and install the great big huge thick papaer gasket

well the place that sold it to you wants you to buy another one from them real soon
let me guess was it the squids out in cali
of course you need to rejet or at least check your jetting
but being this is an al kit you realy need a larger carb if you want a nice long life
again you are the first but the autolube system should be fine it was just fine on the old version

So even though I have gone to an aluminum kit those specs hold true?? good.

Lol. Wouldn't want to go that route. It looked like they only included metal gaskets. The only fiber one I saw I am assuming is the base gasket... Is optimal squish different for each kit, or is there a magic number for all situations?

Nope. Actually i bought all my parts from spmotostore. I am growing a little nervous with their advice tho. I will definitely pay attention to jetting then. I have a set, so I'll probably start with an 88. I intend to go to a bigger carb probably in a few month. Need to save up a little more before I splash down on more parts.

Thanks for the reply jmkjr72! Being someone who has never worked on a 2 stroke before I've had a lot of learning to do. I am just starting to feel I know enough to get started, but still have holes in my knowledge base.

If i am indeed one of the first with this kit I will try to write up a review once I have everything running well.

your squish is adjusted thru your base gaskets

for sport kits i look for 1.5 to 1.1 but no smaller then 0.9mm
if you start getting smaller thatn the 1.1 to .9mm then you realy have to worry about port timings
now race kits are a diffrent beast

on the old version of that kit if you used the head gasket and the thinest basegasket it would come to 1.2 to 1.1 mm

yep the same thing for the al kit you might be able to get away with a little less but just dont over torque it
otherwise you will be pulling the studs out of the engine case

you did buy some studs for the exhaust right you dont want to be pulling bolts in and out of al

this one doesnt have a bridged exhaust port right

if you do have a bridged exhaust you want to dimple the piston

Is this The MKII? if it is,it has a new head design. It actually protrudes into the cylinder. I would check the squish for sure.

I am not impressed with their advice either. Before I ordered my TP Trophy 50cc kit I asked them what spark plug and they said to use the stock one BPR7HS, but the instructions in the box say to use a #8! They just guessed???

haven't bought studs yet, but definitely will before i install an exhaust.


By that do you mean is physical bridge of material across the exhaust port? If so, no. It is just one big opening.

actually, here's a photo of the parts.

Based on my reasoning I'm guessing that unlike the stock setup there is no metal gasket between the cylinder head and the cylinder, just the orange 'rubber' one. The infamous green 'failsafe squish' gasket in my case is gray...?


Lovely eh? Thankfully I had the common sense to question their advice and seek proper knowledge from the good folks here. And thankfully you had instructions that gave you proper advice!


Yup. I will definitely be checking squish now.

So i used a stick of solder to check my squish. My reading was .42 both times. The gasket I used was the thickest one (gray fiber material) and it measures 0.55
If a safe target for squish is 1.2 then I am way off..... what am I doing wrong here, or what am I missing??

Are you measuring in metric? .042 - inch is 1.07 mm. Squish is measured in mm.

yeah, just double checked the measurement and units. .42mm with the fiber gasket. I gotta be doing something stupid...

is there supposed to be something besides that large orange 'o' ring between the cylinder bore and the head?

the oring should be the only head gasket if it is sealed with an oring you do not want to try and use anything else there

when i check for squish i tape the soder across the piston in line with the wrist pin
then i put the head back on and torque to spec and turn it over a couple of times

.42mm with the fiber gasked it crazy that is tighter then a race set up

Yeah its usually almost impossible to get that even with no gasket.

Just went out and tried it jmkjr72's way, taping the solder across the piston in line with the wrist pin. didn't torque the head bolts down, but snugged them up super finger tight.
Got even less this time. probably because the head seated a bit tighter than last time. Now I'm down to .38 one side .39 the other.... this seems really crazy to me!

Well it is what it is....just have to put the appropriate gaskets in to bring it out where it needs to be.

so its smashing the soder thiner then the metal gaskets that came with the kit