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Motovert Pro

Motovert Pro

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Joined
Oct 28, 2008
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RADelaide
Hey guys,

This has got me stumped, with the only logical explanation i can come up with being the throttle cable being to short.

Recently i upgraded my Jialing 125 to a Lifan 150 in my Motovert RX and with the help of a mate doing the wiring all seemed pretty sweet.After getting it running and ironing out a few bugs i dropped the shipping oil out for some decent stuff and bolted on an oko 26mm carby aswell as resetting the valves.
Now comes the part that makes no sense at all.
From here the bike will either not start regardless of how you kick it or after making some checks and adjustments it will fire into life but rev flat out.
The motor and carb came from Ken at DHZ so that shouldnt be the issue (jetting is 36pilot 100 main)
Ive since swapped the carb out for the 22mm mikuni that was on the 125 and the bike is back to starting first kick and behaving like it should,even cruising easily at 100kph.
This is leaving me to think the obvious that the cable is to short causing it to rev flat out because the slide is constantly slightly open.However after kicking the shit out of it while the oko was still on it the plug came out drier than i thought it would have considering all the fuel that should have been in the bike.

So in closing im wondering if anyone has a 26mm oko carb on their RX and could tell me the overall length of their cable and also if possible the length of the cable sheath?
 
ok,
I've no expeirience with oko's but i had this prob with my mikuni and turns out i had the slide in the wrong way, i just turned it 180 degrees and was fine after that,
(not sure if the same would happen with a flatslide oko but thought it was worth a mention to you)
 
if you want anwasier option grind some of your throttle tube off

you will know what im talking about qhwn you take it off and have a look you can that there is a big block that stops the throttle from rolling back just mark a point on and grind away

it is much easier than cutting your outer cable
 
yer mate these carbs have a 'D' shaped slide so theres only one way for it too fit ;)
 
Cheers thanks kid,

Moto, can you take off the air filter to see if the slide is siiting ath the bottom like it should?
at least you will know for sure if your cable is too short.
just a thought.
 
and man check ya cable is routed correctly and not gettin hung up in ya triples .... it happens to the best of us .
 
just cut the cable housing down about 20mm, 5mm at a time until the slide goes down all the way n u have a little slack.....
img0453we.jpg
 
sean01 said:
ok so you have verified tht the cable is holding the throttle slide open

there is a mod kicking around here that shows you how to cut the outer part of your cable allowing for more inner cable.
http://www.miniriders.com.au/251271-post65.html

another solution is to buy a throttle kit from DHZ with the correct cable
Click to expand...



the cable Ken sent with the carby is about one and a half times longer than what i need
 
i had a similar problem. turned out that where i had attached the cable on the slide was wrong and was getting it caught / keeping it open
 
That ran alright when we first put it on there so the cable I trimmed down is fine, I'm thinking if it's running ok with the mikuni again then the oko probably has some crap blocking something in the bowl. Check the needle and seat then make sure the pilot jet isn't blocked, I'm guessing it's needle and seat blockage though.
 
i take it you have blocked off the vacuum fitting on the inlet side of the carb..
vacuum leaks can do weird things
 
sean01 said:
i take it you have blocked off the vacuum fitting on the inlet side of the carb..
vacuum leaks can do weird things
Click to expand...

as this is my first time dealing with an oko im baffled,can you elaborate on this a little more?
 
Motovert Pro said:
as this is my first time dealing with an oko im baffled,can you elaborate on this a little more?
Click to expand...

in the pic the circle shows where the vacuum fitting is.
the arrow shows where someone has blocked it off
if i find a better pic ill throw it up
CarbFamily.jpg

OKO3020.jpg
 
Last edited:
If it was a vacuum issue I think it would have been apparent from the start, it ran fine for a while so something has either moved or become blocked.
 
mr-munro said:
If it was a vacuum issue I think it would have been apparent from the start, it ran fine for a while so something has either moved or become blocked.
Click to expand...

im a little confused lol
your speaking as your helping MOTOVERT PRO with this problem..

in the original post he speaks as the problem happened straight up.
he states it took ages to start them when it did it revved its tits off..

revving its tits off can come about from a couple of things.
stuck throttle slide, just pop the air cleaner off and give the throttle a few twists and see where the slide is returning to.
also make sure the idle screw isnt wound in too far

another reason is a vacuum leak, whether it be the vacuum fitting i spoke about or the carby not pushed far enough in the manifold or the manifold it self not sealing..
on the manifold adapter boot make sure the oring is present or else thts the first place for a leak.

i doubt this revving is due to sht in the carb, there'd be some sort of tell tale like fuel pissin out the overflow or sht loads of kick back.

you also mention the spark plug was dry, this could of been from the fact tht it was revving high and used all the supplied fuel..

so anyways heres where id go from here...

air cleaner off, verify the slide in the carb is at rock bottom.

from turn the fuel on and wait 20 seconds or so then turn it off, remove the carb keeping it upright all the time and undo the drain plug on the fuel bowl or remove the 2 screws holding the fuel bowl on and see how much fuel is present..
obviously if theres not much fuel in there, strip the carb(jets, emulsion, mixture screw and slide out) and blow the carb out thoroughly.

if problem is still there then theres a major air leak..


sorry for making it sound like im speaking to a noob but better to have to much info then not enough..also you have stated the problem but havent mentioned what youv tried to fix it..

anyways see how ya go
 
the jets are fine no blockages,its got to be a carby or cable issue but so far im not lovin okos thats for sure
 
MV Pro if you get really stuck mate, give us a yell... i've played with one or two of those things... totally worth it once up and running....

although, this is the second OKO 26mm thread mentionind similar issues... bit of a worry.. bad batch out there?
 
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