1973 mercury inline six (wont accel)

[Will30]

My buddy has a 1973 mercury inline six 150hp that will not accelerate 99% of the time . But that 1 % it will go . Its hard to start also . I rebuilt the fuel pumps and I checked the carb screens on the carbs and I took the drains out of the carbs to see if they were green or not and they were clean . Once its going it will idle great doesnt miss its nice and smooth. but soon as its in gear and you try to get it passed about 1500 rpm it dies right out unless you let off the trottle. Any info would be greatly appreciated ....

 

[Will30]

This is the boat we were workingon this weekend 77 trimate II with 150hp inline six.





This im my 76 Trimate II with a 150hp inline six



Heres both together at my dock .

 

[winder]

When it starts to die did you try pumping the bulb? Did you try the choke? If that floods or does no change it sounds like a stator. Check to see that you have spark on all 6. There are 2 windings on the stator low speed high speed. You can check the output but need to get the specs on output. I just had a stator go out on a later model inline. .02 Rick

 

[checkmatejetmate]

check 2 make sure the choke isnt stuck

 

[Will30]

When it starts to die did you try pumping the bulb? Did you try the choke? If that floods or does no change it sounds like a stator. Check to see that you have spark on all 6. There are 2 windings on the stator low speed high speed. You can check the output but need to get the specs on output. I just had a stator go out on a later model inline. .02 Rick

Well this motor has a distibutor so the stator isnt the case . I have the stator disconnected on mine right now till I install a new one and it runs fine just runs off the battery . The choke doesnt stick I checked that too . I even rebuilt the fuel pumps because when I pump the primer it will firm up but doesnt stay firm even if its not running .

 

[winder]

Thanks I know little on the older inlines and am learning on the newer ones by keeping it running. I have a 73 150 sitting at my shop and have never run it. I just went over to the dark side. I run a 2.4 200 on a baja and a 83 115 merc built by Dave S on a rallysport going onto a exciter I just bought. Sorry for mistake. Rick

 

[Will30]

Thanks I know little on the older inlines and am learning on the newer ones by keeping it running. I have a 73 150 sitting at my shop and have never run it. I just went over to the dark side. I run a 2.4 200 on a baja and a 83 115 merc built by Dave S on a rallysport going onto a exciter I just bought. Sorry for mistake. Rick

I know quite a bit about the older mercs with distributors but there are still a few things like why wont this motor accel . I have a 1976 150hp laying on my garage floor that does the same thing as my buddys does . And mine was rebuilt because of the problem and it still does it . So I found another and went and picked it up hung it on the Trimate and runs great. I just dont get it and I cant seem to get the right info . Im just about ready to rebuild mine and my buddies motor myself .

 

[winder]

There are quite a few really good with inlines on scream and fly. Alot of old timers that raced them. Nice bunch I would check with them. I ran into Dave there and he built this one I run from junk. I ran omcs for most of my life and the electronics seem easier and maybe better?not sure on that. Rick

 

[rhett mathisen]

hey guys i had a symptom like you had, and the old grease on the dist where it rotates as you move the throttle arm was causing the throttles to open before the initial advance of the dist came in. 2 strokes won't take gas unless they have a lot of timing! check your linkage and see if its the culprit. there is a good procedure on cheking timing and such on the i boats forum search "lynch and synch" for old inlines, it was a great help. My engine is an old 1970 1350 Merc and it is on an 83 BAJA ski boat.

 

[Will30]

hey guys i had a symptom like you had, and the old grease on the dist where it rotates as you move the throttle arm was causing the throttles to open before the initial advance of the dist came in. 2 strokes won't take gas unless they have a lot of timing! check your linkage and see if its the culprit. there is a good procedure on cheking timing and such on the i boats forum search "lynch and synch" for old inlines, it was a great help. My engine is an old 1970 1350 Merc and it is on an 83 BAJA ski boat.

Thanks ill look at that . I brought the motor home from the lake this weekend and have it in the truck . I switched out motors . went to a 1973 115 inline six. Bought it and a parts motor for 300.00 The wire harness wasnt connected so I fixed that and she runs great . She was in the water all last week and was out every day with no problems. But I will look at distributor tomorrow after work . Thanks for the info .