SYM DD50 porting project

This is the place to post your scooter builds; everything from stock Spree restoration to water-cooled drag bikes.

Moderator: Moderator

kauaianman
Spree
Spree
Posts: 201
Joined: Thu Oct 13, 2011 6:05 pm
Location: Ka-Y

SYM DD50 porting project

Post by kauaianman »

decided to post this for input/suggestions/comments so i can possibly get better at porting and tuning.

doing a port job for a customer.

was:
stock SYMdd50 motor
49mm siezed cylinder
8.4 gearing

going to be:
RUIMA 44 Ministroke crank
POLINI CORSA
8.4 gearing

pics of the beginning
0223151035.jpg
0223151035.jpg (75.03 KiB) Viewed 9577 times
SYM tiny intake ports
SYM tiny intake ports
0223151036.jpg (59.9 KiB) Viewed 9577 times
0223151043.jpg
0223151043.jpg (53.62 KiB) Viewed 9577 times
kauaianman
Spree
Spree
Posts: 201
Joined: Thu Oct 13, 2011 6:05 pm
Location: Ka-Y

Re: SYM DD50 porting project

Post by kauaianman »

stock dd50 vs elite S
0223151048.jpg
0223151048.jpg (52.81 KiB) Viewed 9554 times
0223151232.jpg
0223151232.jpg (56.48 KiB) Viewed 9554 times
kauaianman
Spree
Spree
Posts: 201
Joined: Thu Oct 13, 2011 6:05 pm
Location: Ka-Y

Re: SYM DD50 porting project

Post by kauaianman »

first step split case and remove crank
0223151049.jpg
0223151049.jpg (72.24 KiB) Viewed 9551 times
Last edited by kauaianman on Fri Feb 27, 2015 7:49 pm, edited 2 times in total.
kauaianman
Spree
Spree
Posts: 201
Joined: Thu Oct 13, 2011 6:05 pm
Location: Ka-Y

Re: SYM DD50 porting project

Post by kauaianman »

0223151050.jpg
0223151050.jpg (69.98 KiB) Viewed 9551 times
0223151053.jpg
0223151053.jpg (67.23 KiB) Viewed 9551 times
0223151055.jpg
0223151055.jpg (66.68 KiB) Viewed 9551 times
kauaianman
Spree
Spree
Posts: 201
Joined: Thu Oct 13, 2011 6:05 pm
Location: Ka-Y

Re: SYM DD50 porting project

Post by kauaianman »

0223151056.jpg
0223151056.jpg (68.68 KiB) Viewed 9551 times
0223151058a.jpg
0223151058a.jpg (73.14 KiB) Viewed 9551 times
0223151100.jpg
0223151100.jpg (65.11 KiB) Viewed 9551 times
kauaianman
Spree
Spree
Posts: 201
Joined: Thu Oct 13, 2011 6:05 pm
Location: Ka-Y

Re: SYM DD50 porting project

Post by kauaianman »

Step 2 clean up
0223151124.jpg
0223151124.jpg (75.66 KiB) Viewed 9551 times
0223151221.jpg
0223151221.jpg (67.2 KiB) Viewed 9551 times
kauaianman
Spree
Spree
Posts: 201
Joined: Thu Oct 13, 2011 6:05 pm
Location: Ka-Y

Re: SYM DD50 porting project

Post by kauaianman »

step 3 open intake
0223151825.jpg
0223151825.jpg (63.04 KiB) Viewed 9539 times
0223151826a.jpg
0223151826a.jpg (54.25 KiB) Viewed 9539 times
0223151828.jpg
0223151828.jpg (57.97 KiB) Viewed 9539 times
kauaianman
Spree
Spree
Posts: 201
Joined: Thu Oct 13, 2011 6:05 pm
Location: Ka-Y

Re: SYM DD50 porting project

Post by kauaianman »

i open 1 window at a time
0223151900a.jpg
0223151900a.jpg (49.5 KiB) Viewed 9524 times
0223151859.jpg
0223151859.jpg (49.84 KiB) Viewed 9524 times
0223151902a.jpg
0223151902a.jpg (58.54 KiB) Viewed 9524 times
kauaianman
Spree
Spree
Posts: 201
Joined: Thu Oct 13, 2011 6:05 pm
Location: Ka-Y

Re: SYM DD50 porting project

Post by kauaianman »

both windows opened just need to clean bridge up a little
0224151315.jpg
0224151315.jpg (56.45 KiB) Viewed 9524 times
0224151315a.jpg
0224151315a.jpg (47.24 KiB) Viewed 9524 times
0224151317.jpg
0224151317.jpg (46.42 KiB) Viewed 9524 times
kauaianman
Spree
Spree
Posts: 201
Joined: Thu Oct 13, 2011 6:05 pm
Location: Ka-Y

Re: SYM DD50 porting project

Post by kauaianman »

Not the straightest but the best i can do
0224151344a.jpg
0224151344a.jpg (50.61 KiB) Viewed 9524 times
0224151348a.jpg
0224151348a.jpg (57.08 KiB) Viewed 9524 times
0224151454b.jpg
0224151454b.jpg (53.44 KiB) Viewed 9524 times
kauaianman
Spree
Spree
Posts: 201
Joined: Thu Oct 13, 2011 6:05 pm
Location: Ka-Y

Re: SYM DD50 porting project

Post by kauaianman »

finished product
0223151042d.jpg
0223151042d.jpg (58.26 KiB) Viewed 9524 times
0224151454b.jpg
0224151454b.jpg (53.44 KiB) Viewed 9524 times
Attachments
0224151454a.jpg
0224151454a.jpg (51.48 KiB) Viewed 9524 times
Revolutionary
Spree
Spree
Posts: 101
Joined: Sat Jan 25, 2014 6:25 pm
Location: Colleyville, TX

Re: SYM DD50 porting project

Post by Revolutionary »

Looks nice. I like the pics of the whole process. Good for people to see a clean build
User avatar
DirtyE
Elite
Elite
Posts: 559
Joined: Sun Nov 30, 2014 8:13 pm
Location: Bend, OR

Re: SYM DD50 porting project

Post by DirtyE »

Hey k, I brought the floor of my intake with (the big hump) down substantially. I cant tell from the pics if you did or not, but there is a lot of meat there to cut away, and it helps with mixtureflow in from the lower reed petal. Assuming you're running something similar to the CT, you can mock it up and see that that hump blocks almost all the flow from the lower petal. If I was a more adventurous fella, I'd have probably cut that hump right out of there and put a new concave floor in. But im just an around town scooter dude. I like em fast, but gotta draw the line somewhere. I dont know if a JBL weld floor would hold, and I dont have the skills to weld aluminum so I just brought it down.

Err, I can see you did bring it down a little. Good work.

Lets see some numbers in that porting calculator! What pipe?
98 Elite
4 strokes are for cars
User avatar
DirtyE
Elite
Elite
Posts: 559
Joined: Sun Nov 30, 2014 8:13 pm
Location: Bend, OR

Re: SYM DD50 porting project

Post by DirtyE »

This is the worst design EVER! I think there is e nought room above the variator to drop it a little, but thats beyond the scope of my ambition.
Attachments
2015-03-05 21.28.50.png
2015-03-05 21.28.50.png (157.77 KiB) Viewed 9457 times
98 Elite
4 strokes are for cars
User avatar
whitey
Spree
Spree
Posts: 218
Joined: Sun Jun 02, 2013 8:23 pm
Location: United States

Re: SYM DD50 porting project

Post by whitey »

It wasn't designed for a CT reed block. It was designed for the flat reed that came stock. That hump would be the backside of the reeds and reed stop.
01 Honda Elite S 120cc Taida H20
78 Honda Hobbit Athena
78 Honda Express/Hobbit Stage6/Athena LC 70
00 Gilera Runner PM Tuning 172
09 Aprillia SR50 Malossi Team MHR
81 Puch ZA50 Polini
71 CT70 Blue
79 Z50 Red
Post Reply