CDI units

[riverview]

Is it possible that a CDI unit will operate correctly at low RPM but will breakdown under high RPM?

Would be interested in hearing any opinions, thanks

 

[j_martin]

Re: CDI units

Electronics, including ignition, depends on the motor. If you'll share specifics, you can get the info you're seeking.

 

[riverview]

Re: CDI units

The engine is a 92 Yamaha 115HP, it won't rev up under load, start it in the driveway and it revs up like it should.

It starts good, good at idle and runs good up to 3000RPM then it starts to break down with 3200RPM being the maximum.

New plugs, filters, fuel pump pressure is good, all fuel lines checked for air etc.

Took the boat out and had a buddy inject gas directly into the carbs but it still would not rev over 3200 so I think I have to go with something in the ignition. CDI, coils

Any ideas

 

[j_martin]

Re: CDI units

There's 2 ways to go about it.

1. Throw parts at it, starting with the most expensive.

2. Obtain the Manufacturer's manual, tools needed (probably a DVA), and follow the diagnostic procedures down to the failing part, and replace that one part.

You should move this query to the appropriate engine forum.

 

[robert graham]

Re: CDI units

Sounds like dirty/plugged carb jets...maybe get them cleaned before lean fuel condition fries a piston. Good luck!

 

[99yam40]

Re: CDI units

I am with J , testing is the right thing to do with the proper equipment and service manual.

Not sure about your motor but some have low speed and different high speed charge coils to furnish spark

 

[riverview]

Re: CDI units

There's 2 ways to go about it.

1. Throw parts at it, starting with the most expensive.

2. Obtain the Manufacturer's manual, tools needed (probably a DVA), and follow the diagnostic procedures down to the failing part, and replace that one part.

You should move this query to the appropriate engine forum.

I think I will take step 1, I like to have the boat in the water instead of dicking around with it for a month in the driveway.

 

[99yam40]

Re: CDI units

I am not sure why it would take you a month to test things.
normally just take minuets