buddy50

[czechjo]

Oct 1, 2021 8:43:42 GMT -5 farmerjon said:

got a new 2021 buddy50. broke it in like i stole it, to the manual its probly still not broken in anyway. put a yasuni r exhaust. malossi multivar on 6.5g rollis. tryd to mod the carb but there is a fat glob of jbweld on the air screw but, put a 90 primary jet came stock with a 40 idle i think thats what i read. i wanted to move the needle but it was pretty stuck in there didnt want to bend it.thats my engine setup for now, i live at sealevel. I "think" its running too rich.
it has good power, get to 45mph pretty fast, wife following me with the car speed check. temp runs around town 210.
question; i wot for around 3 miles then let off and it dies, when running in wot the temp is about 280 when it dies it goes to 310 then ill slowly kick it with the kicker to see if it seized but its good and it will start up, not right up but it will start. im running a koso temp gauge to the spark plug.
thanks if anyone has any intuition.

im waiting for the 70cc stage6 streetrace and polini 21cp, i have a stage6 clutch and bell but didnt want to waste it on the stock cylinder.
I have been searching, youtubing, parts crossing, about these motors and took a chance and order a crank from Denmark. hopfully it doesnt turn into a $220 paperweight. i plan on making this something i can hammer on, its fun and i crack myself up. ill upload pictures


All the stock carbs come with the air screw blocked off.
You have to use a dremmel or something to open up the air screw and then cut a line to fit a screw driver so you can adjust it. It's actually not hard, i had to do it

[farmerjon]

Oct 3, 2021 22:55:34 GMT -5 czechjo said:

Did you ever install the new crank?

no, ordered it from kgi denmark. havent seen anyone talk about that place, crossing my fingers

[farmerjon]

dio oil pump delete

[farmerjon]

stock cylinder, soft seized it twice, i think, still ran good. better break in the streetrace nice and slow






what I have learned from this is you can hammer on it, wot up to 280° to 300° just dont let off and idle or coast,, keep the rpms up bring down the temperature slowy and mabey i need a bigger pilot jet

[czechjo]

Oct 4, 2021 1:24:30 GMT -5 farmerjon said:

Oct 3, 2021 22:55:34 GMT -5 czechjo said:

Did you ever install the new crank?

no, ordered it from cgi denmark. havent seen anyone talk about that place, crossing my fingers

Get a caliper and as long as parts are the same size they should work. There are a lot of parts that will fit buddy /roughhouse but aren't listed for them

[Zino]

juicing the throttle a few times on deceleration and at stop signs helps bring the temps down .
Added bonus it sounds cool

[farmerjon]

Zino, i wondered that going down a hill if im not giving it throttle how is it being lubricated

[Zino]

You still have plenty of lube with premixing
It is the cooling effect that suffers on deceleration .
At the highest rpms builds this is a bigger issue .

I really dont have any problems with a under 10 k rpm build .
If I am jetted right and juice the throttle as I come off wide open tuns .
My temps may give a small spike then hold and drop .
If i just come off the throttle without juicing they will spike and then come down slowly on there own .

The 2 stroke racers tune leaner on top and fatter on the bottom to compensate for off throttle seizing .
You can tune a little rich by running the bigger pilot jet so it is just above gurgling.
This will help richen the off throttle range .

Here is a quick test to see if you are rich enough on the non adjustable idle jet with the scoot all warmed up .

While sitting still Blip the throttle
3 things will happen
1)the rpms will rise and hang at higher than idle speed and then drop down Showing you are too lean Go bigger on the pilot
2)The rpms will rise and drop quickly back to your target warm idle you are ok to good
3)The rpms will rise and drop below your target idle possibly gurgle a bit and then clean up and rise to your warm idle setting .

Racers take number 3 ,Daily riders will take number 2 first and Number 3 as a second choice .

[czechjo]

Oct 9, 2021 14:36:50 GMT -5 farmerjon said:

Zino, i wondered that going down a hill if im not giving it throttle how is it being lubricated

It's still getting fuel, it's like idling. It shouldn't be getting hot enough to seize though. Probably have to upjet the carb, maybe add a little extra oil too

[snowmeiser]

Just a suggestion to maybe check the piston to cylinder clearance, because from the picture you have a lot of color on top of the piston.

[farmerjon]

those pictures is of the stock cylinder it had about 100 miles on it. i just put on the streetrace and a polini 21cp came with 40idle 100main on a pod filter. currently it is not happy. i think it needs bigger jets, mix screw has to be all the way in to get rid of the hanging throttle and sounded like detination or im just not use to the reeds clattering like that. i cant ride it till the jets come in

Oct 10, 2021 17:18:49 GMT -5 snowmeiser said:

Just a suggestion to maybe check the piston to cylinder clearance, because from the picture you have a lot of color on top of the piston.

[snowmeiser]

I’m just curious what jets did you have in there for that to happen? Also was that with a stock carb and airbox?

[farmerjon]

stock came with a 40 idle then i put in a 90 main. stock airbox and carb

[snowmeiser]

It seems your are burning up in the midrange. I looked into the parts diagram and noticed the carburetor calibration between the buddy and the roughhouse is different. 40/75 for the buddy and 35/82 for the roughhouse and two different part numbers for the needle. A lot of mystery here as I can’t find and needles from Keihin for the PB carburetor . I know from piping snowmobiles as they don’t burn down on top end , to much air and fuel going in. When coming back through the midrange is where it seems to happen. The expansion chamber pipe is difficult to jet for the midrange keeping low and top end in check, especially without a selection of needles and needle jets. I’m about to put a Yasuni Z on my roughouse . You have given me clues for a rough road ahead, unless somebody here had information on PB jet needles and needle jets beside shimming what you have.

[farmerjon]

snowmeiser,
i got my jets for the stock carb from 6sigma. they will send you a kit with instructions for some stock carb hacking. they tell you things you can do to the slide and spacers n stuff for the needle, they advertise %100 satisfaction it costs about the price of a jet kit and they will send you more till its tuned perfect, its just waiting for shipment