KymcoForum.com
Scooters - 50cc => zx50 => Topic started by: Pattyboi33 on June 03, 2011, 01:48:41 AM
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hi every one im new to having a zx ive had the cobra an loved it put a 70cc kit an pipe carb it ran great after some tweeks here an there . where do i start i bought the zx with a bad crank guessing thats because some one put a pipe on with out jeting un-restricting the cdi then holding it wide open all day every day lol. so i took the motor out pulled the top end of and the lower connecting rod bearing was shot so i split the cases an now im having slight trouble finding the crank bearings i should replace those when im in there any way who uses old bearings, then i figured lets pull some power out of it i ordered a 90cc ebay top end kit and a 28mm carb with different intake manifold. does anyone have any tips on re assembly. or anything at all any replay is greatly appreciated. :)
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http://cgi.ebay.com/DIO-90cc-Big-Bore-kit-AF18E-KYMCO-ZX-Fever-SYM-/170649381157?pt=UK_Motorcycle_Parts&hash=item27bb7ee925 (http://cgi.ebay.com/DIO-90cc-Big-Bore-kit-AF18E-KYMCO-ZX-Fever-SYM-/170649381157?pt=UK_Motorcycle_Parts&hash=item27bb7ee925)
90cc top end actuly 82cc
http://cgi.ebay.com/ebaymotors/DIO-power-Intake-28mm-Carburetor-Kit-KYMCO-SYM-ZX-Honda-_W0QQcmdZViewItemQQhashZitem4cf78dedbaQQitemZ330570788282QQptZMotorcyclesQ5fPartsQ5fAccessories (http://cgi.ebay.com/ebaymotors/DIO-power-Intake-28mm-Carburetor-Kit-KYMCO-SYM-ZX-Honda-_W0QQcmdZViewItemQQhashZitem4cf78dedbaQQitemZ330570788282QQptZMotorcyclesQ5fPartsQ5fAccessories)
carb
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On ebay motors, look for a honda dio stroker crank from autotech355, $110 + shipping, includes bearings and seals. I have just put one in my zx, wish I did on my first build.
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Really was the stock crank that bad ? Because I jus bought a brand new stock crank
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No, nothing wrong with my stock crank, I just put the 44mm crank in for the extra little bit. Here in Australia we pay higher prices than overseas, when I looked at getting a new crank, the price was $300, + $60 for the two bearings, + $60 for the two seals. I had the engine open for some inlet tract work and wanted to use a new crank and bearings. Those prices were laughable, if not verging on criminal, so I reused the stock crank and bearings. Then I found the mini stroker crank, $110, I was wrong in my earlier post, that price included shipping. :)
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Yea I read that thread about your crank troubles , so it's not a bad thing to go with the oem because I don't wanna garnade anything down there . Btw Sid do u think a 28 mm flat side is way to much for this little guy ? It's my biggest build ever an I'm kinda nerves ahaha not gunna lie.
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Do I want the 44.4mm ? Or the 52.6 and the 52.6 doesn't have the splines for the oil pump . If I go with the 44.4 witch I most likely am do I need to run a base plate ?
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I am running the 44mm crank and it bolted straight up. I had an issue with the piston skirts touching the crank, but that was due to the piston, a little trimming was all that was needed. For the 52mm crank you have to machine the cases to make it fit and use at least a 50mm cyl. kit.
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U think I'll run into problems with the techniegas r pipe I know the say there good with 50cc but will I be ok with the 82cc kit an 28mm carb
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I can't really answer that because I have never had a Technigas pipe, but you should remember that pipes are designed for a range of sizes. I think with these scoots they work on one size for 50cc to 70cc, then from 80cc to 100cc. Hopefully, someone with more knowlege wil reply.
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Ok thanks for all your help Sid I hope the build goes good by the way do u still have your oil pum connected to put oil in the motor or do u mix it all in the tank if so how did u hook up your feed line an where that's my biggest question!
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I disconnected my oil pump and premix now, 40:1. I have been thinking about going back to the oil injection, but still procrastinating.
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By disconnect it u mean jus in do the lines that go to it ?
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Unhook the hoses and make sure you plug them air tight, I also removed the spindlefrom the pump so that it won't get damaged from running dry. There is a plug you can get to replace the pump, Shaka gave me a link to it, I will see if I can find it when I get back on to the computer.
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Ok and all my parts came in the mail I think there's a nipple on the carb that will allow for the oil pump line like there's a bowl over flow line then there's the vent on the side of the carb then there's an open brass nipple on the intake manifold side of the carb and so I know it's not a vent because it would lean the heck out of the Motor if it was left unhooked so I'm guessing I'll be runing the oil pump I hope I get my oil mixture correct does anyone know how much the pump is capable of pushing out oil like 24 to 1 or 40 to 1
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That would be the vacuum port for the fuel tap. I think the pump mixes at 40:1.
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No the manifold has the vacume nipple on it why would there be two vacuums ?
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I mean it could be possiable but if it was where would the pump push oil into ?
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And btw Sid I can't thank u enough for all your help on this
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The manifold nipple would be the vacuum and the carb one would be the oil one. What carb did you get?
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28mm oko and Honda dio manifold Plus the throtle cable and air filter it was a package deal on ebay
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I got the 24mm OKO kit, good value in my opinion. Running a carb that large I would run premix, You should find a plug in the box to plug one of the nipple holes. I don't know if your pump would flow enough oil for that size carb, it was originally designed for a 14mm carb. If you do use the pump, it would be a good idea to also add some oil to the tank as well to be safe.
When you put your cyl. kit on, have a look at the base gasket on the crankcase, you will see a lot of room for improvement in the transfer ports, but especially in the boost port. I have a thread in this section where I did that with mine.
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Yea your right about the oil hmm I kinda do want to run it still and jus mix in the tank as well but I have a very big feeling that I will have a very hard time tuning the motor because the oil wouldn't be mixing in with the gas . Or an I incorrect ? Because that one of my concerns . Also I read alot about hour thread as I'm going to be needing to do the same but do u have a pic of how u shaved down your piston skirt for the 44.4 mm crank or was that olny on the 47 mm cylinder kit u had to do that I have a 50mm kit
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G'day mate, my concern with using the oil pump would be whether the engine would get enough oil.
Did you get your kit from autotech355? If so, the piston should be ok, I ran mine with no problem, it was the 47mm piston that I had to trim the skirts, this was a cheap chinese kit, having said that, it goes pretty well.
To trim the skirts, I just cut the corners off with a hacksaw and then filed the edges smooth, I don't have a pic of the trim, but I will try to include a pic of the piston, but lately i can't seem to upload pics.
In my thread ZX50 Build,,,Again!!! there is a pic titled clearance check 2, if you have a look at that one you can see where the skirt would hit the crank weight, the corner you see is what I cut off, I didn't get at all technical with it, just measured up 10mm and along the bottom 10mm drew a line and cut, did the same on all four corners.
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I'm not sure if I go it from him I have the link up in one of my earlier posts . And ok that doesn't sound like it's to far in-depth witch is good ! Man this build is alota work an even when it's done I get to spend countless house tuning the carb yay!^_^ haha it's all worth it that's what I have to tell my self !
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Yep, same fellow, Carlos is the one who sold me my kit. He also fronts autotech355. I had a lot of hassle with my original kit, the ports were half closed with the piston at b.d.c. Carlos said I must use 300ml of oil to 1,000 ml of petrol. I ended up having to cut a spacer to raise the jug, then shave 2.7mm off the top, just to get the timing somewhere around right. I now think that if I got the 44mm crank to start with I would have had a lot less trouble.
Once you start getting into this, it is a lot of fun. I had more fun when I had the engine out doing the crankcase work and putting it back together than I do riding it.:)
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Yep, same fellow, Carlos is the one who sold me my kit. He also fronts autotech355. I had a lot of hassle with my original kit, the ports were half closed with the piston at b.d.c. Carlos said I must use 300ml of oil to 1,000 ml of petrol. I ended up having to cut a spacer to raise the jug, then shave 2.7mm off the top, just to get the timing somewhere around right. I now think that if I got the 44mm crank to start with I would have had a lot less trouble.
Once you start getting into this, it is a lot of fun. I had more fun when I had the engine out doing the crankcase work and putting it back together than I do riding it.:)
IDK about that sid.. I came close to beatind/throwing mine in the yard a cpl times....lmao... Riding is pretty dam fun now tho....
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What's up everyone I bought the 44mm crank today I guess it's rly a 43.2 but o well it's still stroker so I'm glad an now I get to wait for it to come in . Did any one switch to studs insted of using the stock bolts for the jug and head ?
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When it turns up you will see it is 44mm. I didn't use studs, I used recoil inserts.
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I just bought new bolts.. I have seen other ppl use studs on scoots tho
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I'm probly going to reuse the old bolts but get the washers that are cut an like spring loaded .. I feel like the biggest retard I can't even think of the name of these WOW . but when u tighten them up they squish shut an the use some locktight on the bolts
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I'm probly going to reuse the old bolts but get the washers that are cut an like spring loaded .. I feel like the biggest retard I can't even think of the name of these WOW . but when u tighten them up they squish shut an the use some locktight on the bolts
lock washer.....lmao
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Don't use lock washers, you won't get a seal.
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LMAO serious brain fart but ok cool good thing u told me that I don't really want an air leak do u know what the torque specs are for the head an jug bolts
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1.5 kg/m or 15 nm. I think that is about 10 lb/ft
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Ok sweet thanks did your crank come with the bearings allready pressed on the crank shaft? Man I can't wait for this crank to come in the mail uhhhh !!!!
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Nope, they were in little plastic bags.
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Did u have a hard time getting them on ?
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If you can get a hold of the right tools it would be easy, I don't have the right tools so it was a bit tricky.
Oil pump blanking plug:
http://www.exportstrength.com/product_info.php?products_id=621 (http://www.exportstrength.com/product_info.php?products_id=621)
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How did. Do it because I have a press but I don't wanna press the bearings up agenst the crank to far is there a space u need inbetween ?
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DON'T press them. You will warp the crank... I DO SPEAK FROM EXPERIANCE THERE. :'(
Use the hot cold method... the 1st time is tricky as sid said before.. A good heat gun comes in handy.. :D ;)
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I heated the bearings in the oven at 350 an then the crank in the freezer worked perfict
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awesome....... ;D
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I was so amped I didn't think it was going to work that well ! Well tomorrow is the big day 90cc topend 44.4 mm stroker crank 28mm oko powerjet carb sweet intake nice cone filter technegas pipe I can't wait to listen to this thing purr like a little kitten !!! >:)
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90cc top end?
You have the next r pipe or a rs2? the next r prolly won't be good enough for what your planning....
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I can't tell what pipe it is but OMG THIS THING RIPS! its all done an put together so happy with the results !Thank you everyone for all your help on this build a special thanks to Sid for all the pics posted on crank case tuning I bassed alot of my crank case work on his pics . An they all seemed to work great
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Good to hear that you are up and running, I'm still trying to work mine out, she must be a woman.
Don't forget to put up some pics so we can all see it. Also some pics of the stripping and building as well,
will help someone else down the road.
Remember, no pics, it never happened. :)
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Oh yes, you can tell between the next r or a rs2... the size can tell that.... :D
Good to hear it's up and running.... but they don't make a "90cc" kit for the ZX.....a mina has a 90 but not kymco
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Ya they do it's rly a 82cc. An Sid sadly enough I'm on my I phone an I can't post pics :| but I took her out today an she soft seized so I need to play with the jetting I'm running a 32 /1 ratio an It smokes heavy but it still seized
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What size carb and main jet are you running? When you put the cylinder on, how much of the transfer ports were open? This seems to be the same kit I got first up.
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I have a 28mm oko power jet the one with that line that runs from the bowl to the nipple in top where the air cleaner goes it's got a 130 main and a 39 slow with the needle clip allthe way botom setting an the transfers were very close to matching I olny angled them slightly there was maybe an 1/8 inch I removed an I shaved a very very small bit off the piston skirt it came way to close to the cases at top dead bottom center infact I think I did hit a Lil but that's all taken care of now . I think I need to up jet the main should I mess with the slow to ? It idles like a dream. Hmm I'm not sure what to do also how does tha air fuel screw work is it turn it in and it's lean an turn out it's richer ? Need some help deffently I wanna do things right !
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I mean it ran sick with no bog at at all from closed to 1/4 throttle an that's all I'm runing it at the moment because I'm still breaking it in
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Is your needle in the 1st slot or the 5th slot?
I'm trying to master this fine tuning crap also, it seems on some papers i have that if the needle is in the 1st slot(all the way down), then you need to downjet 1 size, if it's in the 5th slot(all the way up), then you need to upjet 1 size, i'm prettyy sure that's who that goes.... ::)
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Yea that's how it goes but I up jeted from a 130 to a 135 an it still soft seized btw how did u break in your motor
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When i finally got her together. ::).. I ran a few heat cycles on the stand and actually rode 1/2 throttle? for 2 tanks of fuel, then WFO every chance... :D
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An it hasn't blown up ??? I thought break in was like 500 miles befor u start beating on it
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No sir.... I actually did the same thing when i was "building" it stock....Works great. ;)
I even did that with the s9 i recently built...
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Hmm that's interesting right now I'm dining dangorisly lien but that's nothing I can't fix if I keep the choke on every where lol that makes it plenty rich lmao
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Oh my, we dont want that... :o
Time to upjet... i think id go up on both jets and see...(i'm running a 45pj atm)
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Sounds good time to order jets!
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http://www.treatland.tv/OKO-24mm-carburetor-p/oko-24mm-carburetor-clear.htm (http://www.treatland.tv/OKO-24mm-carburetor-p/oko-24mm-carburetor-clear.htm)
Here is the link to the place i have been getting my jets....
Pretty fast on shipping from them also, of course they sell "kits", i dont think they sell single jets like S.A does
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Ok so I bought a pack of ten main jets an a pack of ten slow jets I'm going to put a 170 main an see where to go from there idk why but I have this funny feeling that I'm going to need a monster size jet
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Good deal.....
:o WOW... A 170? Where about's are you residing? i'm thinking that'll be WAY rich
Oh yeah, btw, have you done a leak down test?...to test for any leaking gaskets... I had a blown head gasket before and it leaned the piss out of my baby....(soapy water works too...lol)
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It's just a wild guess an I'm thinking so because I'm mixing 32/1 so the oil is taking up octain in the fuel and I removed the oil pump . But why do the leak down test ? There all brand new gaskets
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You would be surprised at how many leaks you might have. I have heard that the oko inlet and reed cage can be bad for leaks.
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I been running right around 40:1.....
Yeah, sids right.. I know i've had several leaks around the intake/reed cage myself... ANd a word of caution/advice..... Keep an eye on all bolts and nuts also, mine have worked loose/.... Guess that's why somebody invented loctite ::)..
Carb cleaner is good to use also but of course the scoot needs to run and w/o the fan shroud you cant let it run long.... I woulda thought a 130 would be plenty big enough, but of course i'm still learning... ;)
You can make a tester pretty cheap, if you search for the cheaper prices but around $20 i have in mine. It's not fancy but it works
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I used thread locker on every bolt lol an I used a sealant on the gaskets for the reeds when i did it to
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I don't think threadlock will be too good for retorque.
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Very true good thing I bought a new tap an die set ^_^ so the jets came in any suggest would be cool I get new mains an pjs
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I'm going to do a leak down test I'm holding I don't have any leaks I honestly don't wanna tear this thing down to far again
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So I did the leak test an I'm good now I went to play with some jets an I was revving it an it jus lost spark idk what happen
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It was my coil now I have the tzr50 cdi