1996 Johnson 90 2 stroke rpm help

[Ericle1023]

Gents, I’m looking to see if someone could tell me what my rpms should be around when motors not in gear, while in the water? I have been having this boat for a few months and was told that the motor has recently been serviced. Tried taking it out a few times and wasn’t to happy. The first two times I could not get it started at the ramp. Would get home and would start fine on the muffs. Started looking online and started running some test. Checked compression , 115 on all 4. Did spark test, changed fuel lines new fuel and etc. The boat didn’t not have a tac , so I ordered one online that you wrap around the spark plug wire to try to get an idea. On the muffs the rpms was 200-300. I made a few adjustment and got it started in a plastic 55 gallon drum. Rpms was around 680. Took her out and it ran fine until we decided to head in. Sounded like she wasn’t getting fuel. Stayed at low rpms to make it back to the dock. Decided to take it to someone to get everything looked at and get carbs pulled and cleaned. Well..... they found a few things. For one they had the wrong spark plugs. Anyway I get home and put in the drum and fire her up and bam she’s running..., but rpms are back to 200-300 not in gear. It stays running and I can put in gear but doesn’t that seems very low? Not sure if the little rpm gauge is worth crap but yeah.. thanks in advance

 

[flyingscott]

Get a proper tach first. Your idle rpms should be in the 650-700 rpms in gear and warm.

 

[Ericle1023]

Thanks

 

[jakedaawg]

That tach is not right. That motor will not stay running at 200 300 rpms

 

[interalian]

Some of those cheapo tachs have different settings based on what motor. A 2-stroke like this fires once each revolution.

 

[SpeedCraft]

Y'know I tried one'a them 'Tiny Tachs' on somethin while back. Dicked around forever. Never did get it calibrated to where I believed it was reading right?