Motor keeps bogging down and killing when I try to accelerate. Runs great when it’s wide open; usually idol’s ok, but when I try to accelerate 2 out of 3 times it will kill. It’s like it doesn’t get enough gas running through it in mid range?-? Have tried re-jetting it at Al’s, even they are stumped. Any thoughts? 
Could be a weak fuel pump or excelerator pump or timing or compression loss. Have you noticed a loss in power getting out of the hole?
I had had a simular problem last year with my 72 Merc.
Had the engine timed but was told my compression was getting low. I am running the idle rpm’s a little high in order to keep it from stalling out when I excelerate. The engine doesn’t have enough power to turn the prop and stay running at a low idle.
Hope this helps. Good luck.
thanks! no problem in getting out of the whole, it either runs like a top, or it bogs down at mid throtle as you are accelerating and usually kills…sometimes it “catchs” and gets in to the revs….very frustrating. Someone suggested it’s a fuel problem becaus the engines built in the 70’s ran in the 70’s gas…today the fuel is different, and it gives certain motors a hard time….who knows…
Hi Jon,
If you don’t get it going with the answers from this BB, then try the below BB (click on the Outboard Engines Fourm)
These guys live and breath fixes for older engines.
Dave Gulczinski
will do–thanks!
Try a new fuel filter. It might be a cheap fix. 
http://www.tcoutboard.com
Give Twin City Outboard a call. They should be able to help you out. It could be electrical.
I will try the fuel filter, and call twin cities ob. thanks guys! any other tips…please post..
Don’t forget to check the squeeze bulb on the gas line. On occasion those valves go bad and it could be that one is partly dissolved from alcohol in the new fuels. Another theory is the filter…alcohol dissolves rubber and it could be partly plugged. I had a ’78 Evinrude 70 hp, ran great all the years I owned it although my buddy had a 60 hp 3 cylinder Evinrude and it was a piece of junk….middle cylinder burned up due to lack of cooling, scored the walls and eventually lost compression and the engine was scrap. I believe Evinrude knew of this problem for quite a long time.
yeah, I have heard this was a problem motor with the 3 cylenders…I have replaced fuel line and bulb, I will check to see if the fuel filter has been replaced or not…thanks!
Check to be sure the following are not giving you problems.Be sure the fuel tank vent or hose isn’t restricted.A sudden need for a gulp of fuel also requires your fuel cell to be able to take air in.Also check the fuel tank pick up screen within the tank,it’s nothing more than an inline filter right where the outlet line begins.Someone already mentioned it,but the anti siphon valve should also be replaced if it is sun checked.Did anyone check to be sure the base plate gasket (between the carbs and block) isn’t leaking?Also air leaks in the supply side of the fuel line.Kinda like sipping on a straw with a hole in it.Just some ideas to hopefully help you out.Good luck!
once again, thanks for the tips! I will printing these all off and bringing them to my favorite but frustrated mechanic, John at Al’s Specialty in Rochester. He has commited to standing behind his work, I am very impressed with his service on this frustating project.
keep the tips coming, I appreciate any in-sight!
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