160ho motor/carburetor question issue

[minibiker]

Ive got a 160ho motor with a OKO 26mm carbi and the jetting is 100/36, in neutral my bike revs perfect and rev limits but in every gear when i give throttle and try do more than half thorttle and keep going it keep it steady it lags and bogs sort of, was wondering what are people running with their 160ho motors and 26oko carbs do they have bigger jets?

 

[timeeh]

I would try a 98 main (I think going leaner would get you sorted?) or before removing jets play with the needle height i.e. try placing the needle clip on the top mount (making it leaner), if this fixes your problem then look at a 98, if not try the opposite and put the clip on the bottom mount (making richer) if that works better then try a 102. Either way you go when you put the new jet in reset your needle clip back to the centre mount.

 

[minibiker]

When the oko 26mm was on my 125 gpx it was perfectly fine so dont think going down a jet would be good, i will probably try the clip and play with the tune or maybe go a 102 like you say

 

[my67xr]

when it lags and bogs, does it sound deeper through the muffler ?
if so it could be too rich.


a plug chop at, turned off at WOT, after a couple of high speed runs should show you how it's running.
the ceramic insulator on the end of the spark plug near the tip, will be black-rich, coffee coloured-good, white-lean


i'm guessing too lean ?
have you checked for vacuum leaks ?
if the bike is lacking top speed, without sounding deeper through the exhaust, i reckon it might be too lean.
it'd be a lot hotter after running in the higher rpms.

 

[zwebx]

i would just find what setting it likes to run at? eg air mixture screw all the way in means you need a bigger jet and if it likes to run all the way out you need a leaner jet.. also plug reading

 

[minibiker]

Yeah zwebx thats what i was thinking because it was fine on the 125 so maybe a bigger jet because its a 160, so should i get a 102? or 38? which jet do i change?

 

[minibiker]

when it lags and bogs, does it sound deeper through the muffler ?
if so it could be too rich.


a plug chop at, turned off at WOT, after a couple of high speed runs should show you how it's running.
the ceramic insulator on the end of the spark plug near the tip, will be black-rich, coffee coloured-good, white-lean


i'm guessing too lean ?
have you checked for vacuum leaks ?
if the bike is lacking top speed, without sounding deeper through the exhaust, i reckon it might be too lean.
it'd be a lot hotter after running in the higher rpms.

Just took a picture of my spark plug this is what colour it is

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[timeeh]

Thats BLACK, looks to rich too me

 

[my67xr]

yeah, but was it brand new or at least clean before you ran it ?
and i hope you weren't letting it idle for a while either.


the spark plug needs to get up to the correct operating temperature first,
so it's at the self clean temperature (between about 500 degrees C, and 750 degrees C)


so do a couple of long slight inclines at WOT, in 3rd or 4th,
then after the second run, switch it off while you are still going quick, roll to a stop, then pull the plug out and check it

 

[minibiker]

i switched this off my gpx125 as the 160ho motor had a dodgey chinese one so yeah, what do you mean by this "so do a couple of long slight inclines at WOT"

 

[my67xr]

pick a spot, long track to ride, slightly up hill if you can, to load the motor up.
start the bike and ride it hard, wide open throttle, flat out to higher revs in 3rd or 4th gear
then switch it off and roll to a stop.

you need to start off with a clean, or new spark plug to read the colour correctly.

 

[minibiker]

Havnt got anywhere like that to ride the bike so would i be fine just putting in a new spark plug and when i go to the track after ive ridden it jut check it and if its black just lean it abit and so on?

 

[my67xr]

that will sort of work, if the temp at the spark plug drops from the revs dropping, it will blacken the plug still
have you looked at the OKO thread for someone running the same combo as you.
some people have posted the jet sizes they are running, i would think you need a #38 Pilot, and around a 107 main

DHZ sell kits with 3 of each jets, they are the cheapest to buy from them.

 

[8r3nd0]

I had to go up to 38/102 when I was running my 160 with an oko and was only a turn and a half out on my mixture and it ran hard with no bogs or hesitation. Heaps of guys swear by 36/100 and 2 and a half turns out but in fact all engines can run a number of different setting in a number of different places so grab a couple of pilot jets up and down and like wise on the main and experiment for yourself there's no magic setting that someone's going to tell you, and don't try to tune it to get the miracle 2 and a half turns out on the mixture because what ever works works.



Sent from my iPhone using Tapatalk 2

 

[Phil67]

mate i run a 107.5, i still reckon it;s lean. So there is no magic number, each bike is different.

 

[my67xr]

mate i run a 107.5, i still reckon it;s lean. So there is no magic number, each bike is different.

i'm pretty sure mine is running the same main jet too, it was the biggest i bought at the time.
i might grab another couplebigger mains, next time i'm going past
Show and Go Motorcycles
i need to get the bike back home asap.

 

[minibiker]

True that but ive seen more than 5 people say their jetting is 38/102 so ill try that and try a tune till i get it right if that dosent work ill just do as you say put different jets and change the tuning

 

[Phil67]

i'm pretty sure mine is running the same main jet too, it was the biggest i bought at the time.
i might grab another couplebigger mains, next time i'm going past
Show and Go Motorcycles
i need to get the bike back home asap.

yeah I'm the same, it was the biggest one. Same as what my missus says to me every night.

I'm half thinking going OKO or maybe PE 28 soon though.

 

[my67xr]

my 150 Lifan had a strong top end using an OKO 28,
i couldn't get it to take off too quick after trying out 4 or 5 jets in the mains, and same in the pilot, or after adjusting the needle clip though.