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Sym dd50 build!!
Posted: Wed Apr 04, 2012 2:00 am
by Madman
So I want to start this build thread as I'm finally going to rebuild my engine with a BBK from kn kikaku which I have on order and will get in a week or so.
I'm going to need advice as I go on this one! I'm going to do it all myself and am going to port out the boost port and the intake port as well.
Parts I have now include.
Yws v8 pipe
Oko 21mm
Ct intake 4 petal reeds
Kitako Koso variator
Clutch springs
Center spring
Parts on order
48mm 74.9cc BBK kn kitako including head
Oil pump plug
Oil seals for crank
Crank bearings
So my first question is should I get a new crank it has about 10000miles?
Thanks.
Re: Sym dd50 build!!
Posted: Wed Apr 04, 2012 3:20 am
by veedubh20
change the crank. dont worry about crank going breaks...
all new parts seals, bearing and bore.
Re: Sym dd50 build!!
Posted: Wed Apr 04, 2012 3:40 am
by paulpauly7
theres some nice stuffer cranks on yahoo auctions for a good price
Re: Sym dd50 build!!
Posted: Wed Apr 04, 2012 8:51 am
by Downsouthdio
Might as well if your going to have the block split

Sym dd50 build!!
Posted: Wed Apr 04, 2012 10:26 am
by Madman
Re: Sym dd50 build!!
Posted: Wed Apr 04, 2012 4:02 pm
by kingkamehameha
Get the malossi crank
Re: Sym dd50 build!!
Posted: Wed Apr 04, 2012 5:30 pm
by Dio89Elite
If you have the funds, "DO IT!"
after all the block will be split anyway and everything else is going to be new too = FRESH!
May I ask what blue paint and method did you use? Did you do it yourself? It looks great!
Re: Sym dd50 build!!
Posted: Thu Apr 05, 2012 12:07 am
by veedubh20
get a stock stroke crank 41.4mm malossi, honda oem or rumia with thicker conrod.
dont get mini stroker crank!!!!
Sym dd50 build!!
Posted: Thu Apr 05, 2012 12:17 pm
by Madman
Dio89Elite wrote:May I ask what blue paint and method did you use? Did you do it yourself? It looks great!
Well I got some spray paint it was car paint and decanted it into jars. Then I airbrushed it on about 3-4 coats sanding between coats a little, messed up a couple of times with runs, sanded them out and recoated. Then gave it three coats of lacquer clear coat sanded it back and polished it out, took about 5 days couple of hours a day.
Sym dd50 build!!
Posted: Thu Apr 05, 2012 12:23 pm
by Madman
veedubh20 wrote:get a stock stroke crank 41.4mm malossi, honda oem or rumia with thicker conrod.
dont get mini stroker crank!!!!
yeah I think I'll just get some bearings and inspect my crank when its out may be fine and I'll save some money. Looking around and some cranks are expensive, went to the shop to price out original Honda and sym cranks and they were about 150000¥ or 180$ about! I'll be saving that!
Sym dd50 build!!
Posted: Fri Apr 06, 2012 5:53 am
by Madman
Some picks before I tear it apart for the rebuild!
Looking forward to this!!
Still waiting on parts.
Re: Sym dd50 build!!
Posted: Fri Apr 06, 2012 6:49 am
by paulpauly7
where in japan do you live?
where did you buy that pipe?
how is it compared to the chinese chamber pipe?
Sym dd50 build!!
Posted: Fri Apr 06, 2012 10:05 am
by Madman
Live in Tokyo, bought the pipe from "kn kikaku"
The Chinese pipe was good at high revs and gave a couple of miles more but at low revs it was really boggy even when tuned well, the Chinese one stated on the site where I bought it that it is not suitable for BBK so I switched over before doing the bbk! Also Chinese pipe was a little louder.
Re: Sym dd50 build!!
Posted: Sat Apr 07, 2012 12:16 pm
by veedubh20
Madman wrote:veedubh20 wrote:get a stock stroke crank 41.4mm malossi, honda oem or rumia with thicker conrod.
dont get mini stroker crank!!!!
yeah I think I'll just get some bearings and inspect my crank when its out may be fine and I'll save some money. Looking around and some cranks are expensive, went to the shop to price out original Honda and sym cranks and they were about 150000¥ or 180$ about! I'll be saving that!
Im selling my rumia crank on ebay.. sn jpnscooter..
Sym dd50 build!!
Posted: Mon Apr 09, 2012 6:58 am
by Madman
veedubh20 wrote:Madman wrote:veedubh20 wrote:
Im selling my rumia crank on ebay.. sn jpnscooter..
I saw that but it only ships to USA and I live in Japan, so I'll get one from Taiwan or china or just inspect mine, have no problems with it now so it should be fine!!