timing and miss

[gearwrench]

2001 johnson 90 misses coming off idle to about1600 to 1800 rpm.manual u ses abox with lights etc.to check timing.this miss has been happening since new.dealer told me it needs to break in.any help appreciated

 

[Silvertip]

Re: timing and miss

Doubt its an ingnition miss. Sounds more like a carb or link & sync problem. There is a transition as the throttle plates move from idle through the range to wide open. Probably a synchronization problem where the carb butterflies are not operating in sync.

 

[Seasport]

Re: timing and miss

Hard to beleive that a 2001 motor still needs to be broken in! Checking the link & sync isn't hard if you have the service manual.<br /><br />If you want to check the timing, you need the optical analyzer to set the timing statically but you can still check it with a timing light with the motor running. You need to take off the plastic cover on top of the flywheel to access the timing wheel & pointer. Some say that the timing light can effect the optical sensor but I've had no problems.<br /><br />Idle timing is fine on muffs. The catch is you shouldn't run the motor at WOT without a load. This means you either have to (carefully) hang off the back of the boat at full speed and check the timing or you back the boat on the trailer into the water so that the water intake is covered and do the measurement with the boat in gear and WOT on the trailer.<br /><br />BTW I can provide some DIY instructions for building your own optical analyser if you want to go this way. Requires basic electronic skills.

 

[gearwrench]

Re: timing and miss

thanks for the replies I'm going totry the linkage sync adjustments first and see.If I need to time where would I buy tooling {box}?

 

[Seasport]

Re: timing and miss

The ignition analyzer is available as a BRP part. Fairly pricey though - about $300. You may be able to find one cheaper on Ebay.<br /><br />You could check the timing with a timing light as described but you would need to adjust the WOT timing a notch at a time with the motor stopped and then retest. The manual describes how to do it.