76 OMC 190 swapped with 77 OMC 175

[capt3311]

I cracked the block of my 302 in my 77 Gulfstream (77 Ford OMC 190hp). I bought a used 302 (76 Ford OMC 175hp)
I swapped everything over, Carb, Alt, Dist, coil. It ran great at trolling speed, as I didn't have all the mounting bolts in, I didn't want to run WOT. I had to run it up a bit to get the bow up in the wind. It ran rough, but not the engine. It turns out, the upper bearings were dry and rusted . I replace all bearing and am ready to get going again. I'm having issues with setting idle mixture. Timing is set at 10+1 BTDC. Idle is set at 500-600, Not under load. It starts and runs, for a while and stalls if I leave it alone or throttle up....
Fuel Pump Pressure? I disconnected the fuel line and tried to run it to get a pressure, but wont start with fuel line disconnected.

Getting frustrated...

 

[jimmbo]

What Carb is on it, Holley? If so, Holley's have a fair sized Fuel Bowl and the engine should be able to start and idle for about 20 seconds.
Based on your description, it sounds like a Fuel Starvation issue. Is there a Water Separating Filter? It might be plugged or Water Logged. Is there any other Filter in the Fuel System

 

[jerryjerry05]

You should get a FP pressure without it running.
Unhook the fuel line, stick it in a jug/jar then key off, jump the solenoid.
That should push a fair amount of fuel.

Check the coil.New coil?
Resister in the coil? Test the voltage going in. 9v
Key on start and run until it stalls, then touch the coil and see how hot??
If it gets so hot you can't keep your fingers on it?? then it's bad.

 

[capt3311]

Jimmbo,

Thanks for the info. It is a Holley Carb. I thought it should be able run a bit, but I may have been testing so many things at this point, that the bowl could have been empty by the time I tried to get a fuel pressure reading. I did install a new water separating filter before beginning any work. I also drained the tank and started with fresh gas. the interior of the tank and all the hoses are clean . I will get it running again today and retest.

 

[capt3311]

jerryjerry05,

Thank you for your reply. It's a mechanical fuel pump. I did pull the hose from the carb and tried to put the guage on the hose. got very low reading 3-4 psi, and not much fuel came out. It's supposed to run at 7-9. I did install a new coil along with an electronic timing system. I hooked it all up as to the specs. My timing is spot on. I checked the voltage at the coil. it's getting 12v per the instructions. and does not get very hot, warm but not so that I cant touch it. I put in the Petronics unit for 8 cyl, I'll look up the model number if you like?

 

[capt3311]

Well,
2020 hasn’t been all bad....
It is the end of a very good boating season. The boat is finally reliable enough to take out almost every weekend (had to work a little OT) this last summer. My problem all summer of ‘19 was a silly mistake. My distributor was off 180*, hence I could time it, but it wouldn’t run full open.......
I did replace the fuel pump as well, but still had the stalling problem, so I called in a favor from a professional mechanic friend of mine.
Thank you guys for all the ideas. I know it’s been a while.
Happy Boating!!!