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motorbike Honda Benly 1986?

I have a honda benly twin cylinder put all new plugs, leads ,etc and it runs but it will only run on both cylinders if the lead is just connecting to the left hand plug if I connect it completley it loses it s compression on the left hand cylinder, any ideas

Public Comments

1. To me it says that it is only firing one cylinder,Take spark plugs out connect leads and rest them on the top of engine where you can see them spark then turn engine over with kick starter see if they both spark.
2. change the coil and rectifier.
3. Check the plug cap
4. To check the spark plug caps, unscrew them and install each one on the other wire. If it only runs on the other cylinder now, then you found the problem.
5. Hi, if it still has the original metal spark plug caps on take them off and fit new ones, NGK are good. Check that the HT leads are not shorting out anywhere the best way i found of doing this it to take it into a dark place start it and look for the sparks. If that does not work try swapping the leads over then the coils to try and find out what is not working. GOOD LUCK.
6. Yup - just change caps first , next step would be leads. If not then it could be something more serious. Doesn't sound like it is tho.