51 Re: k100 intermittent spark on one cylinder. Fri Aug 20, 2021 12:23 pm
92KK 84WW Olaf
Life time member
One thing to note on the plug caps.
Sounds like they are original. BUT, the condition they are in can and does destroy the coils. If original a good idea to replace them as they are damaged if loose fitting or used without the bobbins. The description of the inside of the cap eaten away confirms they got used without the bobbins. This is going to cause issues on sparking to needs to be fixed before going too far into other areas. Us of carb cleaner can verify if you do actually have any leaks.
The bobbins are needed for most of the NGK plugs if they show screw threads on the top of the plug, if not fitted you get arcing [ticking sound] and that's got bad consequences for the plug caps and the coils.
BSK Speedworks at Leighton Buzzard can send you HT leads.
Also, if you go checking valve clearances, be very very very careful. The bolts on the cam/valve cover are meant to be very little more than hand tight. Your K has been sitting out so the 'rubber' seats are very likely hardened. Not cheap but replacement of the rubbers is recommended because new ones are soft. One of these bolts goes into a camshaft bearing cap and is very easily stripped with disastrous consequences. New soft washers and little more than hand tightening should mean no problems.
Sounds like they are original. BUT, the condition they are in can and does destroy the coils. If original a good idea to replace them as they are damaged if loose fitting or used without the bobbins. The description of the inside of the cap eaten away confirms they got used without the bobbins. This is going to cause issues on sparking to needs to be fixed before going too far into other areas. Us of carb cleaner can verify if you do actually have any leaks.
The bobbins are needed for most of the NGK plugs if they show screw threads on the top of the plug, if not fitted you get arcing [ticking sound] and that's got bad consequences for the plug caps and the coils.
BSK Speedworks at Leighton Buzzard can send you HT leads.
Also, if you go checking valve clearances, be very very very careful. The bolts on the cam/valve cover are meant to be very little more than hand tight. Your K has been sitting out so the 'rubber' seats are very likely hardened. Not cheap but replacement of the rubbers is recommended because new ones are soft. One of these bolts goes into a camshaft bearing cap and is very easily stripped with disastrous consequences. New soft washers and little more than hand tightening should mean no problems.
Last edited by 92KK 84WW Olaf on Fri Aug 20, 2021 12:35 pm; edited 1 time in total