Planet Minis

50rider340

15:1 compression ported stock 50 head jetting and fuel???

I know people have ran them but I did a search and nothing came up that gave me the answers I wanted.

Anyway here is the build: I ported the head and bath tubbed the combustion chamber, it came out awesome. I Spent a lot of time on it and didnt go to over kill since it was staying 50cc's. This head is Prolly one of the better heads that I have ported. Other mods consist of port matched intake, lightened flywheel, 15:1 compression power roll piston, rev box, super coil, Kitaco cam, high volume oil pump, HD auto clutch, polished intake side on carb, and two bros Air filter. IF i think of anything else I'll post it up.

First what jetting did you guys go with stock is a 58 so I was thinking like a 60 or 62.

Second what fuel would you suggest, I know 93 isn't going to cut it and e85 I would have to run HUGE jets and the nearest e85 station is in MA so that is out of the question. So the two fuels I have ran it down to is CAM2 or C12 which do you think would be better?

Motor tech guys let me know what you think. thanks.

slimbo

post up some pics of combustion chamber.

Kurlon

I think you'll find 93 may work. I ran 13:1 or so with my 72cc motor on low test all day long.

On the clutch, lighten the weights if you can, raise that engagement speed.

chrisc161076

I am running the same piston but hace fitted my ported head yet, 58 main and 100octane fuel works well, l live in the uk though so we might have different fuel specs

50rider340

First pic is just the 15:1 compression piston installed.

Side view of the piston So much domb to the piston talk about having some quench.

heres intake without a valve in it. dont worry that nic that you see in there was taken out before assembly lol.

Polished exhaust port, I use wet sand brillow pad cut out in a circle and put it on a dremel. Lasts longer and is way cheaper than buying the darn dremel ones that last like 5 minutes.


Last is bath tubbed combustion chamber. Doesnt look like much by itself but if you put it next to another stock head you can see the difference. Basically I just took out the vavle seat machined marks, polished it some and then re shaped the chamber a little bit. Nothing over kill.

35mastr

We need bigger pictures!!!!!!

chrisc161076

Nice, any chance you could talk me through the bath tub bit again?

Also are you going to measure the squish? What gasket are you running l just went with the stock ones?

chasetheface123

That a poweroll setup? Ive been wanting to do that setup for a while now..... Anyone know if it will clear 70 valves?

schofell84

clean up the top of that piston with some sandpaper and it will help with detonation too.

conant19

and burch always said mine was a cheater motor

LongMooie

my 50 set up is...
stock piston with gasket mod (two outter parts)
stock head ported by myself i dont know how good of a job i did but i opened them quite abit
70 intake and carb (stock jetting needle clip is on the second to bottom i think)
pro curcuit pipe
takegawa inner rotor
horstman grim reaper clutch
i only really rode it once cos theres no where to ride here
but i used shell Vpower and it ran nice
im no engine tuner though but this fiddy revs real nice

anyone know how you go about putting bigger valves in the stock head?

crf50luke

just go to your local airport and by AV gas its about 100 octane and i use it in both my race quads

50rider340

chrisc161076

If you PM me remind me tomorrow or sunday I will write up how to do it I just got in and its a 11:30 and I gotta get ready for a race tomorrow. As for the squish I clayed it just to make sure it wouldnt hit the head I should have miked it out but I didnt. For gaskets I just used stock crf50 head and base gaskets.

Chasetheface123

Yup its a power roll set up, it absolutely rips I am very impressed with it. I'm not sure it it wold clear 70 vavles. I believe the valve angles are the same so a little dremeling to the piston it should work.


As for what gas I chose I ended up scooping some C16 "stuff is amazing." ZERO detonation which is good. On the power roll website they say to use 105 plus octane with anything above 14:1 compression otherwise aviation fuel would be the ticket.

Sorry for the big pictures I thought for any of the motor tech guys they would enjoy being able to see every deatail hahah.

TRT

avatiation fuel evaporates too quickly... One goood thing about being in Detroit alot of the local gas stations carry 110 octane fuel...

50-50

Do you guys mean Powroll?

Wow 15:1 on a 50 is impressive. Please post a riding video when you're done! This thing should sound pretty good.

chrisc161076

I run 100+ octane pump gas, and it runs great, with a similar set-up.