2008 Sunl 250 Wont run.... By thetucks (Read 5,567 times)

[thetucks]

I have posted this in another forum but havnt had any luck.

I have a 2008 sunl 250 scooter that I just got. Its not running. the previous owner could not get it to run so he sold it to me.

This is the honda clone engine.

I checked the timing and the timing mark on the flywheel is lined up with the piston at tdc. I took the valve cover off and the valve lobe is lined up correctly also. I can get it to idle sometimes smooth but most of the time ruff. but if I try to give it any gas it will die. also it will not idle very long if I let it set and idle. after about 30 secs it will die. I have replaced the carb with a new one. I have replaced the electric choke. I have checked the fuel pump and it works good. I am stumped at what it could be. Any help will be greatly appreciated. thanks.

[davec]

valve adj??

[Alleyoop]

Yep, and I answered him on the other forum guess he did not like my answer which was to FIRST ADJUST the valves then adjust the Carbs Fuel Mixture. And I will say the same thing here.
Sorry but it is not going to get fixed all by itself.
Alleyoop

[davec]

Seems like you/we gotta answer everything multiple times
Why???
Oh well, some day he'll get the answer he's looking for

Be safe my friend

[thetucks]

im sorry to have taken too much of your time by asking for help. If you would have noticed I responded to the other forum that it has been done and there has been no change. So No its not the answer I needed.... sorry......

[Alleyoop]

You did not take up our time but did you adjust the valves and how did you adjust the carb? If it is running rough and hard to start those are your problems. If you think it is something else tell us and we can tell you how to test and or fix that part.
Alleyoop

[racerx125]

what about compression? Have you done a compression test? check spark plugs and check if you get a good spark and also check for bent fuel lines and if you have a fuel filter between fuel tank and carb then check it. I don't know much about this but I do know what basic stuff to check

[thetucks]

thanks alleyoop... That is the method I used to adjust the valves. I could figure out how to do the cold/ non running version. as far as the carb. I took it off and set the air mix screw to 1 full turn out. My buddy has the same scooter and thats what his was set at. The scooter will actually start and idle kinda rough. if I attempt to give it throttle it just dies. even if I just turn the idle screw all the way up it will die. I actually havnt done a compression test yet. I may need to do that.

as far as setting the timing. I know when you turn the motor by hand the piston can be at tdc and the cam will be on the timing marks and off if you turn it a complete turn. if that makes sense. How do I know which tdc the cam needs to be set at? thanks for all the help.

[Alleyoop]

One turn out on those motors is NOT enough Normally all your motors no matter what size will take 2 to 2 1/2 turns out. 1 Turn is to LEAN adjust it with the motor running and turn it COUNTER CLOCKWISE 1/4 at a time wait 10 seconds so that the motor adjusts to the the new setting. That is why it will not take THROTTLE TO LEAN.

AND WHEN YOUR DOING this make sure the AIR FILTER IS ATTACHED otherwise it will be for not.

What you want is to GET THE HIGHEST IDLE from the Adjustment and it should IDLE anywhere from 1800-2000 rpms.
If after the Carb Adjustment to get the HIGHEST IDLE is to HIGH lower it using the IDLE SPEED SCREW.
Alleyoop

[thetucks]

I actually had it set at 2 turns out this morning. but after I checked my buddys settings I changed it. I will do as you said and change it while its running. what I dont understand is it done smooth...it just seems to me like the timing is not right. but it is all lined up.

[Alleyoop]

I don not believe it has anything to do with the timing unless the timing chain jumped a tooth but you verified it is right on. Adjusting the right amount of fuel to air will smooth it out some and the idle to where it runs the smoothest. If you can put up a VIDEO on how it runs that would help, it could also be a plug that is not gapped correctly or fouled or little loose.
Alleyoop

[thetucks]

ok im going to get up early and adjust the carb. ill get a video of it running. I took the plug out of my buddys machine and it didnt make a difference on mine. his runs perfect. does it make a difference which rotation I set the cam to? thanks for all the help.

[Alleyoop]

If you bring the PISTON up on its compression stroke the valves should be closed and the timing pointer should be pointing to the mark. You cannot miss the compression stroke it will be a little harder to turn at that point. All other turns will be easy.
Alleyoop

[thetucks]

ok thanks alleyoop. I really appreciate the info. I will check all of this and report back tomorrow. thanks.

[Alleyoop]

BY the way here is the SERVICE MANUAL FOR IT.
Alleyoop

www.motorscooterguide.net/Manuals/Honda_CN250_Service_Manual.pdf