Free Mods!!!

This is a hole in a X7 clutch thingy.. Cost was nothing.

http://i224.photobucket.com/albums/d...fs/clutch1.jpg

http://i224.photobucket.com/albums/d...fs/clutch2.jpg


I wouldn't do it unless i know exactly how to fo it. It was pretty hard and time consuming. I drilled holes and then used hand files to get it to look like that. Very time consuming!

take off the plastib body panel..it saves about 2 pounds and also gives you easier access when wrenching on the bike...plus you can show off your engine:P

I made a reed inlet. It accepts stock (And possibly tuning reeds aswell but I'm not sure.) horisontal Minarelli scooter engine reeds.

It's made in steel and the reeds are put in a angle facing a little down towards the intake.
If you do an angle - which btw does nothing at all to engine power, it just looks good - you can't angle it too much since you need to be able to get the bottom screws into the reed inlet where you bolt it to the cylinder.
I use a special allen key that you can angle a little as you turn the screw.

I will draw a hose from the bottom of the crank case and up to the intake that will lead the pulse to the carb. So the intake itself needs two small pulse hole tunnels drilled into it UNLESS I use a carb that doesn't require a pulse.

Anyway, here's some pics. Not the best pics but I guess you get the idea.

http://i224.photobucket.com/albums/d...s/IM000029.jpg

http://i224.photobucket.com/albums/d...s/IM000034.jpg

http://i224.photobucket.com/albums/d...s/IM000035.jpg


I have some more pics on my uploaded images btw.

Nice work Pongo but did you put a window in your piston the width of your boost port? So which carb are you running with that setup of yours?

Yea there's holes in the piston, I uploaded pics of that a while ago actually, press the "my images" button.

Edit: Might aswell link it. http://www.pocketbikeplanet.com/mini...mageuser=25653

The boostport is very extreme (next cylinder will have a completely new design on the intake/boostport) but this is an old cylinder that has seen it's brighter days.

I havn't decided what carb to use yet. I'm thinking a 17mm will be allright for my setup but you never know. I tried a 17mm carb once but it was a chainsaw carb and I couldn't get the mixture right, (nope I didn't forget about the pulse lol) tillotson carbs are insanely sensitive and hard to set up!
I guess the stock 15mm would work fine but I want the last squeeze of revs out of it hehe. Not to mention a better quality carb!

I'm thinking about removing one piston ring aswell btw. Apparantly it shall give less wear and less friction/resistance. It does make sense, I might try it and see what happens. I've read some positive results about it.

Once I saw that pic I remembered it. I've had no ill effects from running just the top piston ring. Just make sure you take a fine file and shamfer (ease) the sharp outside edge of the bottom of the piston to help keep ware down to a mininum. A 17mm carb should work very well with your setup I would think. It's good to see you take a ride through here again. It's been a little while since I seen you rolling through here.

Aye I always try to keep sharp edges away lol.

Thank's m8, good to see you too. I've been busy with my RD350 (see avatar) so I have mostly been over on a RD forum.

Hey peeps! I have some information to share with you.

I have recently started up my x7 engine again (mounted on a goped) and would like to give a warning about the exhaust port.

I did an insane portjob on that cylinder long ago when i thought I would never ever run the thing again, (I have another cylinder that I will use now.) I was just playing around with it and tried to perfect my porting skills.

The exhaust port duration landed on about 180 degrees (about 17mm high port) and it doesn't work well at all. Not that I'm surprized lol, I knew it was very over dramatic but decided to try it anyway just to see if it's really as bad as I suspected.
It completely lacks torque, it's so bad that you can't even get the engine to rev out when riding it, although my engine is geared to about 70km/h and I'm sure I can get the jetting much better. But still, you can feel it lost power.
So yea, for those of you who want to port, keep the exhaust port MUCH less then 180 degrees. I can't remember the stock durations now and surely they differ depending on what company that made the cylinder. But they're much less then 180 degrees.
But anyway, I'd try to keep the port close to stock actually, (and raise it successivly in small steps until it's good) and have it widened so it's about 26-28mm wide.

So yea, take this warning seriously, 180 degree port duration = very bad. Peace!