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1997 50 hp

D

dalel

New member
Good afternoon, I hope I explain my situation well enough for you to understand Just purchased this boat and motor. When I went to look at it it ran well but after about 10 sec at idle it would die. It would start right up but would die after a few seconds unless you advanced the throttle to 1500 rpm, then it would run along happily. When I went to pick it up it would not run at all. I got it home and could not get it to start. I sprayed some carb cleaner in the carbs and it started right up, but would die at idle. Give it a little throttle after starting and rpm would shoot past 4k, back the throttle down a bit and motor rpm would shoot past where I wanted and shut down. You could jockey the throttle and keep it running but the rpms were swinging wildly in response to throttle movement. Any ideas? I think the spark is good and strong.
 
Check the compression. Then the spark which should jump a 7/16" open air gap. If that's okay do the carbs.
 
Thanks, I appreciate the reply. The boat is at the lake and I did not have my compression tester with me. I made a spark tester for my 175 I will check the jump on Friday when I go down I grounded the plugs and the spark looked very strong in direct sunlight, but I will check with the tester. It ran very well when I looked at it but would not idle below about 12-1500 fo very long.
 
Compression 135 top 130+ bottom spark jumps 1/2 no problem. reeds look okay when lookin through carb. How much fluid should flow out of pump when cranking?
 
fuel delivery.
fresh fuel and portable tank, verify pump output.
Known issue is the enrichment solenoid endcap cracking, and lines from enrichment solenoid to carbs deteriorating and allowing air in.
Check the vent, and also check valve at tank if equipped.
Beyond that, decarb and clean.

Fuel pump should output 4-6 PSI.
 
Thanks for reply. I did pressure check the solenoid and there did not appear to have any leaks. I will check the hoses and I guess the carbs are next. Thanks again.
 
Thanks for all the support. I went through the carbs today, put them back on and fired right up. Starts instantly and idles forever. The synchronization needs to be done, I will attempt that tomorrow. With the 4amp system on the special motor the book says the linkage on the timing should be 2 " ctr-ctr. It was set at 2.25, the linkage will not even go down that far, I damaged the joint trying to do so. It runs slightly rough but I suspect proper adjustment would fix that. Anyone have any tricks or warnings for the carb synchronization?
 
I found it hard to go to the actual measurements of the linkages provided in the manuals, I turned them until they stopped and used the timing light to determine the result. You can cut the link rods if need be, however I never had to, timing lights don't lie.
I always synchronized carbs using a mercury filled vacuum tester designed for the task.
When in doubt, richen it up.
 
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