[sledman8002002]

Could you recommend a wireless rpm meter? I have been meaning to get one and am having trouble deciding.

As mentioned there are plenty of options on Amazon. Below is an example page...

Amazon.com : tiny tach

Not that its a big deal (its just a battery), but be aware, some wont shut off (usually the least expensive), some will automatically while others will shut down/off, but manually.
I prefer the manual shut off style for my own use. They can be wired direct to the plug wire if you want to leave the tach in place somewhere on the unit.
Or should you just wish to quickly see an engine's RPM, you can easily add/crimp a small clamp or clip to the device's wire end and simply remove it when done. (As pictured below)
Wired either way, they're an excellent item to have on hand.