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NC35 upper radiator displacement to access plugs.

Posted: Mon Aug 22, 2022 4:53 pm
by Foxy400
I am trying to remove the HT leads and the spark plug caps from the front two cylinders. As NC35 owners will know, getting in there is a pain in the backside. Haynes says "remove the upper radiator lower mounting bolts and swing the radiator forwards". Sounds straightforward enough. They are on the left side of the radiator. I have removed both of them. With the top two 'lugs' acting as hinges (both with rubber bushes) the radiator is supposed to swing out and up. And it does, about 1.5 cms!! I don't want to force it any further for fear of damaging either of the lugs, or buggering up the hoses connected to it.
With the radiator moved as far as it would go I jammed a piece of wood between the lower edge of the radiator and the cylinder head, to hold it still, while attempting to get my hand into the space above the front cylinder head, so I could pull off the plug caps. With the radiator acting as a cheese grater against the back of my hand I managed to get two fingers (not a thumb, which would have been more useful, but which was pretty much dislocated by now) around the front, left cap and with a lot of effort pulled it off the plug.
But with the very limited space I cannot get a strong enough grip on the right side cap to remove it. It almost feels like it's stuck on the spark plug and won't budge.

What am I doing wrong? Surely the radiator should move more than 1.5 cms? If draining the cooling system and disconnecting the hoses turns out to be the only solution then Mr Honda is an arse.

How in hell a plug spanner could be got in there and turned 90' to fit over a plug I have no idea.

Re: NC35 upper radiator displacement to access plugs.

Posted: Mon Aug 22, 2022 9:51 pm
by CMSMJ1
You need a piece of card on the back of the rad t prevent the cheese grater effect :D

ALso - I reckon you'll probably get better access if you unhooked the top mounts of the rad too - and then it can push out some more for better access with yuor western sized hands...

The caps are fecking tight usually...and so if this is too much ballache...get the tanks and carbs off...and get at it that way!

Re: NC35 upper radiator displacement to access plugs.

Posted: Tue Aug 23, 2022 10:31 am
by CB1pod70
Unfortunately Mr Honda is an arse and even the simplest jobs on the V4's can be a pain.
As above, undo the top mounts as well and then you can push the whole rad forward and down - there is no need to drain the system

Re: NC35 upper radiator displacement to access plugs.

Posted: Tue Aug 23, 2022 12:31 pm
by Foxy400
There was a lot of swearing which obviously helped because l got both plug caps off. The front coil + leads & caps, is now on my bench.
I also have the original, dead coil, returned to me by GF when he replaced it.
Using my trusty Sealey multimeter l check resistances.
Primary circuit should be 2.5-3.5 ohms
Secondary (with cap) 14-25k ohms.
Results:
Old coil primary 3.5. Secondary 0. So it’s junk.
‘New’ coil primary 0.3. Secondary 24.2k.

So the new coil has a very low primary reading (checked and rechecked). What does this tell me? Is it also junk?
Would this be the cause of the front 2 cylinders not firing?

Don’t you just love physics?! Give me biology every time 😆

Re: NC35 upper radiator displacement to access plugs.

Posted: Tue Aug 23, 2022 3:34 pm
by Foxy400
As the old adage says..’If it moves it’s Biology, if it smells it’s Chemistry and if it doesn’t work it’s Physics’😂 Never a truer word..!

Re: NC35 upper radiator displacement to access plugs.

Posted: Tue Aug 23, 2022 3:36 pm
by Foxy400
Another one that still makes me laugh..’Those who can, do; those who can’t, teach; those who can’t teach, teach PE’.

Re: NC35 upper radiator displacement to access plugs.

Posted: Fri Aug 26, 2022 9:23 am
by magg
New coil reads like CDI not TCI. Primary resistance much too low could cause failure of control unit. Maybe cause of ignition issues. Old coil primary OK. Coil secondary resistance rarely goes 0. Usually goes open circuit or high than spec. You could also measure resistance between a plug lead and the coil mount point. Should read open circuit. Have you removed leads form old coil and measured secondary resistance.