Logo
FULL SITE MENU

1999 9.9 hp no start issue

A

arcojet

New member
Just bought a used boat with a 1999 yamaha F9.9w trolling motor that will not start. I pulled the plugs and it looks like there is a little spark but it is hard to tell while Im pulling the starter rope. I squirted a little gas down the intake and tried that but will not even fire.
Any suggestions on what to do? Thanks
 
Re: 9.9 no start issue

UPDATE: I hooked up a timing light and pulled the rope, there is spark at both plugs. I get a pop out of the exhaust once in a while and a backfire out of the intake once. My compression tester doesnt have a small enough adapter for this motor so I couldnt get an acurate test but I put my finger in the hole and it does have some compression, it also sucks my finger in on one of the strokes. Think it's out of time?? Timing belt looks good but how do I check the timing marks to see if it's in time??
 
Re: 9.9 no start issue

its the carb and fuel pump

check to make sure the oil is half way up the xxxx mark

i have the same motor and have to rebuild the dang carb yearly!!!
 
OK, Cleaned the carb and can get it to run but not very well. Checked the compression and it is 75 on both cylinders with a leakdown of 4%. What should compession be?? and can anyone tell me if this is an "interferance engine" or not??

Thanks
 
Just cleaned it to see if it would start. I dont know about outboards but isnt 75 a little low for the compression. I think the leakdown at 4% is good but I think I could see some marks on top of the pistons that looked like half moon shapes, I just wonder if the previous owner broke the timing belt and bent the valves ???
 
The " half moon shapes " are likely there on new pistons.-----------Compression gauges are not always acurate.------------Some motors are equipped with automatic compression release for easier starting.----------------Best to revisit the carburetor , as they are easily plugged by letting gas sit in them for extended periods of time.
 
Back
Top