sparks per revolution

O

outback32

Regular Contributor

• Jul 3, 2020

• #1

I have a 2000 70hp jhonson im going to hook up a tiny tach for tuning. I need to know how many sparks per revolution this engine has.

 

R

Rwbutler

Advanced Contributor

• Jul 3, 2020

• #2

After it comes out of quickstart,three

 

faztbullet

Silver Medal Contributor

• Jul 3, 2020

• #3

After it comes out of quickstart,three​

Click to expand...

Are you saying it sparks more than 3 time in Quickstart????

 

R

Rwbutler

Advanced Contributor

• Jul 3, 2020

• #4

Rwbutler said:

After it comes out of quickstart,three

Click to expand...

No, i said after it comes out of quickstart,three.

 

F

fdrgator

Outstanding Contributor

• Jul 3, 2020

• #5

Doesn't Tiny Tach get it's signal from a spark plug wire? If so, I believe that is one spark per rev.

 

O

outback32

Regular Contributor

• Jul 3, 2020

• #6

I got it figured out at wide open throttle the boat maxes out at 4800 rpm. my manual says it should be 55 to 5800. the prop says 13x19 do i need a different pitch prop

 

F

flyingscott

Outstanding Contributor

• Jul 3, 2020

• #7

Your manual should say 5-6000 rpm and you want to be propped for closer to 6.

 

O

outback32

Regular Contributor

• Jul 3, 2020

• #8

yeah thats why I was asking about prop size. mine is 13x19 I was wondering what size prop I should try

 

B

Boobie

Silver Medal Contributor

• Jul 3, 2020

• #9

Try a 13x15.

 

O

outback32

Regular Contributor

• Jul 4, 2020

• #10

I have 17 that came with the boat i think il try iy and see what happens. Will I hurt anything by running the 19 at 4800 rpm

 

F

flyingscott

Outstanding Contributor

• Jul 4, 2020

• #11

Yes, you will be lugging the motor. What boat is this on? Are you positive your tach is correct?

 

O

outback32

Regular Contributor

• Jul 5, 2020

• #12

the boat is a 18x60 lowe roughneck with bowfishing deck and lights. I have a brand new faria tach at the dash and a mini tach at the motor both were reading 4800 to 5000

 

faztbullet

Silver Medal Contributor

• Jul 5, 2020

• #13

Need to lower pitch a least 2 sizes