Honda SJ100 No Power

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Rasputin
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Honda SJ100 No Power

Postby Rasputin » Fri May 20, 2016 4:07 pm

1999 Honda Bali SJ100.

Was running fine a couple of weeks ago then completely lost power. Starts first time every time on the button. But engine will not rev and only reaches about 5 to 10mph.
Exhaust removed and cleaned internally by soaking overnight in strong caustic soda solution. Well washed out after.
Auto choke checked as per Haynes scooter book.
Great big spark and fuel in combustion chamber. Head gasket not blowing.
Tried removing air cleaner filter. Same result.
New spark plug fitted.

Brakes not binding.

Any helpful suggestions please? (I have already thought of some kindling, paraffin and a box of Swan Vesta. :boom: )
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andyscooter
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Re: Honda SJ100 No Power

Postby andyscooter » Sat May 21, 2016 8:51 am

too much fuel getting in?

is plug wet and smelling of fuel when taken out
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Rasputin
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Re: Honda SJ100 No Power

Postby Rasputin » Sat May 21, 2016 9:50 am

That sounds right. Plug is very wet. How to adjust please?
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andyscooter
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Re: Honda SJ100 No Power

Postby andyscooter » Mon May 23, 2016 8:07 am

should be a screw on the carb somewhere for mixture

normal running is normally about 1 and a quarter to one and a half turns out from all the way in
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andyscooter
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Re: Honda SJ100 No Power

Postby andyscooter » Mon May 23, 2016 8:08 am

also make sure spark plug is gapped properly

just because it is right plug doesn't always mean its the right gap as plugs will fit other bikes as well
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RoadieRoger
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Re: Honda SJ100 No Power

Postby RoadieRoger » Mon May 23, 2016 10:19 am

The float in the carb.float chamber determines the amount of fuel it lets in from the tank . The float rises in the chamber and causes a needle valve , usually made of nylon , to rise and cut off the supply, thereby preventing too much fuel entering the chamber . Flooding/too much fuel could be caused by , wrongly set float level , punctured float , a sticking needle valve or the needle valve face is worn or damaged leading to fuel leaking past . A tapered jet needle is clipped to the throttle valve by a spring clip and usually has 5 grooves , this determines the mixture for the main jet . If you are unsure try the middle position .The second would be weaker and the fourth richer . This throttle valve is controlled by the twistgrip . The slow running adjuster screw does just that by altering the tick-over speed , this is the job of the pilot jet . Hope I haven`t told Granny how to suck eggs ! Another not so obvious running problem which causes the opposite of too much fuel is a blocked breather hole in the fuel filler cap , always worth checking .
The fact that it was running recently and now it won`t very well , suggests a `dirt`problem .
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Rasputin
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Re: Honda SJ100 No Power

Postby Rasputin » Mon May 23, 2016 1:23 pm

Thanks for suggestions. Carb cleaned out.
Did find only .5v going to auto choke from reg/rec so have ordered a replacement.

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