90hp ignition timing @ high idle

[Searider]

Hello ,
I would like to check the ignition on my 90hp 2 stroke / 99 modell . I do have the manual and the only question I have - is there any other way to check the ignition timing with a timing light at high idle rather than described in the manual = with a specified test prop in a water tank ??

Thanks in advance & Happay Easter !

[99yam40]

What RPM is it calling high idle?
I have only seen timing listed as full advanced or full reversed (retarded)
I would think you could do it under way on the water at the specified RPM, or in the water at the ramp with boat still tied to trailer in gear

[robert graham]

Same make, model and year as mine, and I'm just curious why you're "checking the timing"?....are you having any problems with the motor?

[Searider]

Hi ,
The max RPM check is described in the manual as following :

full advance side engine speed 90hp @ 5000 +/- 500RPM = 22 +/-BTDC .

That`s quite a bit and with tighting up the boat and to run it with WOT I will not reach the 5000 RPM ..
I am also not sure I want to do this test on the sea with 40 knots speed ..

I am not having a problem at the moment but I got the engine end of last year with a stator problem . In addition I had an issue with the carbs which I solved by cleaning and installing rep kits .
Now I just want to make 100% sure that all other settings are within the specs and want to check the timing .
Any advice appreciated !
Cheers - Jürgen

[99yam40]

Well the least dangerous way would be to put the test prop on it, that way the motor is loaded up properly and you can make sure it reaches proper Timing and RPM. If it cannot reach the proper RPM even if you are at proper timing it would mean there is some other problem.

If you can find smooth water and have someone run the boat while you check to see what the timing is at with timing light, it only takes a few seconds to see what the timing is. If you need to adjust then shut down , adjust and retest.

On my C40TLR, I checked where the WOT linkage set the timing at on the wiper with motor off and marked it.( which is up against the full advance stop).
Disconnected the timing linkage from throttle linkage, fired up the motor with timing light hooked up,and then moved wiper to where the linkage would put it at WOT, while motor throttle linkage was still at idle, just long enough to see where the timing was. Motor speeds up but will not run away with throttle still at idle.
But then I did check timing while at WOT on the water after that with only myself. But my motor was within reach of the controls.

Make sure you mark the timing where you want it to be with white paint so it is highly visible and easy to see especially during the daylight.

[Searider]

Hi ,
Great - thanks ! Next week I`ll be in France where the boat is and I will check this out !
Happy Easter !