compression test adapter

Good morning...

As I try to troubleshoot my cranky #3 cylinder (doesn't like to fire when cold), I of course need to do a compression test. I didn't have a tester, so I bypassed this for a while... I did take the valve cover off, and all of the clearances are within spec. That, and I can verify "thumb compression," and it doesn't feel different across the four. Granted, my thumb isn't as highly calibrated as most compression testers, so I needed to get a tester.

So, I bit the bullet and purchased the cheapest Harbor Freight tester I could find -- $5.99 on sale -- so shipping was actually more than the tester. It had 18 and 14mm plug adapters. Those of you more experienced in these matters probably see my problem. From what I can tell, my plugs have 12mm threads. Oops. So now what? I've tried a million searches on Google for "compression test adapter" and other iterations but have thus far come up with nothing. Do any of you know of a source that makes adapters, from either 18 or 14 to 12mm? And yes, I suppose I'd be willing to spend more than I did on the tester, though I'd hope an adapter wasn't more than $8 or so.

Thanks!
Nick

Hi Nick - I use MAC p/n CT112 12mm adapter on my KZ550. Hopefully you can locate one or a similar adapter from a tool supplier.

Have you checked at any auto parts stores near you yet?
Just about every auto parts store that I've been in (Checkers, Auto Zone, Pep Boys, Napa, etc) has had them.

Other good places to check would be at either a plumbing supply/fastener specialty store, or at Homey Depot - they've got aisles, and aisles full of that stuff there! :ohmy:

Yes, I've checked at local hardware stores and the Auto Zone near me, and people look at me like I have 10 heads when I ask if they have such a thing. I don't know what it is; I'm fairly new to the area (little over a year here) and I definitely haven't seen the do-it-yourself spirit I saw when I lived in CA and GA. Problem is, I haven't found a local bike shop that will work something "this old" either (sheesh, it's younger than I am, which is more than I can say for my '75 Yammie project!).

The maddening thing is, I hit the magic keyword string on Google a while back when I was looking for an adapter and found a place that sold them for $7.50. For the life of me I can't remember what that combo was, but at the time I didn't think I'd need it. Go figure.

Thanks!
Nick

Might try a NAPA dealer

Success!

The magic Google search string is "compression tester adapter 12mm spark" and brought me to...

www.etoolcart.com/index.asp?PageAction=VIEWPROD&ProdID=5053

After $10.50 for the adapter and $9.95 for shipping, I will have paid nearly double what I did for my compression tester. Oh well. Now to see if compression is the cause of my cranky #3...

Thanks!
Nick