Spark plug hole too small

[Hfb1957]

One plug hole I believe I can just run a tap in it. The threads look ok just dirty. On the other one the threads are completely gone. I will have to get an insert installed in the hole. My problem is that I don’t know if it is a 10-1.25 mm or 10-1.5 mm. I have been able to find the 10-1.5 mm at auto zone. Would it be better to put an insert in it or drill it and tap it to 12 mm. I have watched some videos and read up on them and I think I can install an insert. My plugs are c7hsa. All the spec sheets just say 10 mm. Thanks for any advice on this problem.

[rrietman]

my advice would be to get the correct head for your engine. not that hard to do. the bigger plugs work better, that's why honda changed them. Ed (LM) probably has one ready to go. I have a bunch that will need rebuild cheep. either way you will be better off getting it right, not to mention the whole thing fooling around with helicoils can be a cluster.
Good luck
Randy

[DJM]

The Owners manual I quoted earlier actually gives the plug as C7HW 10 X 12.5

I'm sure this is a typo and should be 10 x 1.25 but easily checked on any 10mm plug using a thread gauge.

LMs advice sounds good, go for the later head if you an find one.

[Hfb1957]

I am going to search for a head that I can afford. I don't have much money because all my money goes to my wife's cancer treatments. In the mean time I'll put in a coil so I can at least maybe get her to run. I only paid $150.00 for the old girl, so if I have to spend a little it will still be worth it. I have it firing good and the compression is good so I believe the main thing now is get a spark plug screwed in. the carb will probably be the next thing I disassemble and clean. I just like to tinker with motors on mowers and other things. I have brought old engines to life before and maybe I can do it again. I will try to get the plugs marked c7hw but if not maybe the c7hsa will work. Thanks

[rrietman]

C7 10x12.5 is 10mm dia x 12.5mm reach. any C7 plug will get you running.
Good luck
Randy

[Hfb1957]

I installed a Heli coil and got the spark plug back in. After a few seconds of cranking the lady fired up and ran like a top. I will be rebuilding the carb because it had fuel coming out of the overflow when it wasn't running. I also noticed that the only thing where an air cleaner should be was a spring attached to the carb with a hose clamp. I'm not sure what the spring is or what the air cleaner should look like. Any help on the air cleaner replacement would be greatly appreciated.

[rrietman]

Some of the original rubber air cleaner connector hoses had an internal wire (spring) to hold it's shape. that may be what's left of your connector hose or someone put a foam pod on it and the foam fell apart. both the hose and the air cleaners are now being repopped and are available from the usual vendors (david silver, tim mcdowell,ohio cycle) probably others.
where are you located? I can send you a correct core cyl head for shipping. If Conus probably $40-50.
Good luck
Randy