My 2000 Softail does not have a tach but I like to keep the RPM's within spec for oil pressure requirement. I found a tach/hour meter in one of my old toolboxes. This tach has a wire that gets wrapped around a plug wire and the other wire has a clamp for a ground.
I ran the bike with this little meter connected. It reads between 4600 and 4700.
My question.....is this reading half the RPM's? There is no paperwork with the little meter

 

No.
Cause I don't believe any Harley could wind up to 9000+ RPM

..L.T.A.

 

Every spark read is one revolution. Otherwise V8 would be 8 times.

and quit measuring rpm’s and just ride. You’ll be fine.

 

Here is your instructions in the PDF shown

https://tinytach.com/gasoline-tinytach

That RPM is getting up there for your old girl. I rarely if ever hit 4000? No need to.

There is no RPM requirement for oiling.

Harley doesn't need a lot of oil pressure to get oil thru engine. And roller bearings don't really hold oil pressure.

There is plenty of lubrication at 800 RPM for idle and the relief valve opens at 35 or so to prevent over oiling pressure.

 

I don't believe those things are that accurate. They're made for small engines like lawnmowers aren't they? Just buy a real tach. Look on ebay or whatever for one of those speedo tachometer combos. Its plug n play and will drop right into you dash panel.

 

@brakeless if they are a good quality they are very accurate. I used to use them tuning hot rods back in the day because they were more accurate than the analogs I ran. They have been used for timing for decades.

 

Quick search in my area (norcal) I found half a dozen like this.

 

he doesn't have a tac, Rip

Clarification if it's reading 4000+ but his "ear" is hearing 2000 would be helpful
Cause the way it's worded, "is this reading half the RPM's?" would be the opposite

If that's the case, depending on age and model it may or may not be adjustable

.L.T.A.

 

they are.
They're too simple not to be.
Typically found on power equipment, true, but they're not just for lawnmowers

Tiny-Tac has been around a long time

..L.T.A.

 

My mistake typing......should have read that the tach reads between 460-470. Doubling the reading should put it in the correct range according to my service manual 950-1050 rpm
The newer models can be used for 2 stroke and 4 stroke.