switch box testing

[yasser]

Dear all

I have question regarding mercury 2.5 260 hp switch box testing how can I test it if its working good or bad and whats the perfect reading (ohms ) for it

please let me know
regards
Yasser

[outasite]

What problems are you having? You can swap the packs around,if the problem follows the pack,it's bad.

[HStream1]

Outasite is correct. You need a DDT to test one and even then its not completely accurate. Depends on where the short might be. Also switch box reacts differently when in real world operation.

[yasser]

I have problem my engine is 280 hp with 260 electronics but my engine is not turning more than 9600 rpm even with small pitch of propeller so I think there is problem with the switch box because I do testing for stator and trigger and coil its all same as chart specification and I do test for switch box I get different reading than the service manual (1300-1500 ohms ) but I get( 764 ohms )

please let me know iif you have idea .
what's the problem with my engine .

regards
Yasser

[johnboy 88 vegas]

Whats the rev limiter in your computer?

[yasser]

there is no rev limit in my ACU is brucato with no rev limit and its setup up 13000 rpm

[outasite]

Your total setup will have a lot to do with max rpm,9600 with stock 280 porting,I would think your on the backside of the curve.Do you have access to another switch box,or better yet a pair to try out to see if there is a difference?

[bigbluechevy454]

9600 is about it for 280 with stock porting

[Michael J Giesler]

9600 is about it for 280 with stock porting

Yep with 1.87 gears that's it 2.1 gears around 10,000 but trust me a your not going any faster the trick is to keep the motor in it's power band and past 9000 rpm's a stock ported 280 is done