sikk mx 125 cc breaking down at high end


21 replies to this topic
  • jgiampapa

Posted 06 April 2008 - 07:11 PM

#1

Hi!
:thumbsup:
I have a 2006 sikk mx 125cc that i bought used. It sat for a year, when it was shown to me it would only run with the choke on. It was popping with no high and mid range. So, being an idiot, I said "i'll take it!" Took the thing home, drained the old gas, cleaned the carb...and she started right up and gave me a great ride. The next day, I went out again and the same issues I observed when I first looked at the bike, as soon as I got to the trail. brought it home, cleaned the carb again, and rode for the rest of the day with no problems. Bike sat all week, and this sat when i rode, i had a different issue.The bike would idle and have good mid range but start to break down on top end. so...here's what I have done so far:
cleaned the carb yet again and flushed the tank.
changed the plug.
changed the coil.
adjusted the valves.
dropped the c clip on the needle jet down one.
tried tuning the mixture screw. with little or no effect.

the compression seems good, although i haven't put a gage on it.

could it be the carb is junk? or could i have a cdi problem? :thumbsup: or neither.

any suggestions?
Thanks!

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  • DesertDog_12

Posted 07 April 2008 - 07:07 AM

#2

use an air hose on the carb when cleaning, the gum is hard to get out and get into those narrow channels and keep the gas from flowing properly, make sure the jet is proper for your elev.

  • jgiampapa

Posted 08 April 2008 - 06:37 AM

#3

Thank you for pointing me back in the carb direction. took it apart and really examined it this time and was able to find a few areas where it was really clogged. rides fine now. Thanks again!

  • DesertDog_12

Posted 09 April 2008 - 08:16 PM

#4

good deal :
who's next

  • custom pits

Posted 30 July 2009 - 03:54 PM

#5

Thank you for pointing me back in the carb direction. took it apart and really examined it this time and was able to find a few areas where it was really clogged. rides fine now. Thanks again!


does your sikk have a nuetral problem yet. i just put a new clutch in mine and the nuetral is still happening

  • jgiampapa

Posted 31 July 2009 - 06:45 PM

#6

yeah... i had 2 of them. i had the 107 and the 120 (110 and 125) my 110 had problems, got the shift kit from sikk mx, helped a little bit...the 125 was never really that bad. but I sold them both. redirected my attention to old dirt bikes. I dunno if you know about the shift kit or not...or if they are still available...last I knew you could call sikk mx directly and get it for free. I got mine 2 years ago. fairly easy to install as long as you have a clutch nut tool.
Fun little bikes, though.

  • custom pits

Posted 01 August 2009 - 02:42 PM

#7

i have replaced the clutch already so working in the gear box is no issue. if sikk does not offer that paticular shift kit could i find one possibly elsewere maybe. i had to hunt down a clutch cause sikk said no go, engine is a 06

thanks

  • s_t_hayes

Posted 26 August 2009 - 09:46 PM

#8

I just purchased a used Sikk 120 on wednesday and had some problems too.... http://s815.photobuc...ent=Sikk125.jpg

The bike take off real good when gradually twistn on it...but when I wham it out, the bike seems to skip on me almost like the clutch is grabbing and letting go. I am thinking there could something wrong with the clutch plates?.. which I will take off in the next day or two. What do you guys think it could be?...clutch or transmission? Would any of you have an idea of what kind of engine is in the bike (jailing,zongshen.etc) and if clutch plates for it are available?

Everything else on the bike seems fine...cleaned the carb and jet's with cleaner and air hose.

Here's a picture of my SSR DX3 that I got in March and put some money into

http://i815.photobuc...ithshock030.jpg

I appreciate any help and advice you can give.

  • hick487

Posted 02 December 2009 - 08:07 PM

#9

heyy, my clutch on my sikk mx 125cc motor is going, where would i find new friction plates? is it the same as a honda 125? or can i buy parts rite from sikk mx?

  • SRAD97750

Posted 02 December 2009 - 08:38 PM

#10

but when I wham it out, the bike seems to skip on me almost like the clutch is grabbing and letting go.

I don't understand this exactly... Does the engine rev up but you get no forward progress? Does it bog/die out when opening the throttle fast? I can help but i need to know what this means... -BIG DAN:thumbsup:

  • s_t_hayes

Posted 23 February 2010 - 10:53 PM

#11

Honestly...I never noticed that someone replied to me.

Well....let's say that I'm cruising just applying a little throttle going through 1st 2nd 3rd and 4th....works just fine

When I'm just cruising around in any gear then give a lot of throttle...it will speed up real quick then will start to rev up then go down..rev up than go down....causing the bike to speed up than slow down like someone hit the brakes real quick..then will speed up again. I did adjust the clutch adjusting screw on the right side, which was screwed in pretty far....I was really surprised by that so I backed it back out and readjusted. Problem is, I did not notice that until I took the engine off the frame so I don't know if it fixed it. I don't know if a badly adjuster clutch screw would cause problems like that.

I still have the engine..just kind of stuck...did not put the engine back in because I would rather fix the engine so I don't have to keep disassemblying my bike more than I ride it.

  • MrBlah

Posted 24 February 2010 - 02:44 PM

#12

Honestly...I never noticed that someone replied to me.

Well....let's say that I'm cruising just applying a little throttle going through 1st 2nd 3rd and 4th....works just fine

When I'm just cruising around in any gear then give a lot of throttle...it will speed up real quick then will start to rev up then go down..rev up than go down....causing the bike to speed up than slow down like someone hit the brakes real quick..then will speed up again. I did adjust the clutch adjusting screw on the right side, which was screwed in pretty far....I was really surprised by that so I backed it back out and readjusted. Problem is, I did not notice that until I took the engine off the frame so I don't know if it fixed it. I don't know if a badly adjuster clutch screw would cause problems like that.

I still have the engine..just kind of stuck...did not put the engine back in because I would rather fix the engine so I don't have to keep disassemblying my bike more than I ride it.


sounds like jetting, way lean on the main, how does the plug look?

  • s_t_hayes

Posted 25 February 2010 - 10:06 PM

#13

The plug looked pretty good...no light gray...was not black or crusted either. I will try adjusting the carb a bit to see what that does. Besides the carb running lean, do you think that the coil or cdi would have anything to do with it? I am pretty new to working on motors so I have base knowledge of them but really do not know what problems a bad cdi or coil would cause. It's funny that I would say that because I just split a Lifan 125cc 4 up and replaced the transmission with no problem ....the alignment of the rear sprocket was off about a quarter inch which caused the chain to come off and get caught in the front spocket breaking 5 teeth on 2nd gear. Let that be lesson....dont get too excited after you put a new motor in a bike that you forget to check the alignment of the sprockets before you ride....it can be a long walk back to the trailer.

Thanks for your input and keep it coming! I usually don't mess with the carb at all but its worth a shot...especially if a twist of a screw saves me money!!!

  • SRAD97750

Posted 25 February 2010 - 10:17 PM

#14

yeah... check this...
http://www.thumperta...ad.php?t=327405

If not helping. Tell me... Does it feel like it could be the chain skipping a tooth on the gear? Does it grab again really hard after letting go quickly? My pitbike will run the chain around the rear sprocket and give some nasty jerks, but only when I'm hard on the throttle. It was silent and never fell off the sprocket. Tighten your chain tighter and ride for a short time like that grabbing the throttle hard... if it fixes it, then your suspension is messing with your swing angle from sprocket to sprocket. I needed a one inch longer linkage. Sat the rear up higher and the chain stayed nice and adjusted through the entire arc of the swingarm. -BIG DAN:thumbsup:

  • MrBlah

Posted 26 February 2010 - 04:34 AM

#15

The plug looked pretty good...no light gray...was not black or crusted either. I will try adjusting the carb a bit to see what that does. Besides the carb running lean, do you think that the coil or cdi would have anything to do with it? I am pretty new to working on motors so I have base knowledge of them but really do not know what problems a bad cdi or coil would cause. It's funny that I would say that because I just split a Lifan 125cc 4 up and replaced the transmission with no problem ....the alignment of the rear sprocket was off about a quarter inch which caused the chain to come off and get caught in the front spocket breaking 5 teeth on 2nd gear. Let that be lesson....dont get too excited after you put a new motor in a bike that you forget to check the alignment of the sprockets before you ride....it can be a long walk back to the trailer.

Thanks for your input and keep it coming! I usually don't mess with the carb at all but its worth a shot...especially if a twist of a screw saves me money!!!


exactly what did the plug look like?

if it's the cdi they usually work or they don't, what you are describing is a lean main jet

  • s_t_hayes

Posted 26 February 2010 - 09:29 PM

#16

Thanks on for the info on the cdi...didn't know that. I will try to take a picture of it this weekend and post it on here so I can get your advice. It does make sense about the carb being too lean know that I have been thinking about it.

Good thing is, I still have about 3 weeks of winter to work on it....bad thing is... 3 more weeks of winter that I'm stuck inside thinking about riding.

  • s_t_hayes

Posted 28 March 2010 - 08:14 AM

#17

Well....I still haven't had time to buy another deep socket to remove the spark plug but I did adjust the fuel/air ratio and it seems to be running better...but I think is may be a little too high now because I am getting a little back fire. Weather is getting better now in Kansas so I will be able to take it out to ride and adjust as I go.

SRAD - The engine would rev up but when you would open the throttle wide open real fast, the engine would bog---feels like the clutch would engage and disengage. Any other suggestions are appreciated.

I really can't wait to ride, my money is getting all tied up buying my first house so I need to get out and relieve some stress !!!!

  • SRAD97750

Posted 28 March 2010 - 09:31 AM

#18

Have you had the problem since you adjusted the clutch screw? I would have figured that it being so far in, It would do what you were describing. Does the engine rev up when the Clutch disengages? Or does it bog, to the point where the clutch could just be doing what it should, and grab again really hard when the engine catches up out of the bog? -BIG DAN:thumbsup:

  • COD4SNIPER2

Posted 28 March 2010 - 09:30 PM

#19

cuts out at top end, then picks back up, then back down......Sounds kinda like what mine did when I forgot to turn the fuel on....It has enough leakage to ride around town, but when I would pick up the speed heading out of town, it would do what you were going through.... Until I got home to turn off the gas to find it was already off, aaaadurrrr, lol
Sounds like fuel/jetting to me too...

  • RoostDome191

Posted 16 June 2010 - 05:05 PM

#20

I also bought a sikk mx 125, and too am having clutch and carb issues. Is there a Number available for Sikk so i could contact them regarding a new engine. Within 2 hours of use the machine sprouted multiple mechanicle problems. Any info would help. Thanks




 
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