Evinrude 7.5 hp – Hard to pull

[Parnold498]

I have a 1955 Evinrude 7.5 hp.. Just replace the impeller and runs great but it is hard to pull. A friend tested the compression and said it was great in both cylinders – I think around 120-130 but not sure.

Since I had shoulder surgery three years ago, Its harder to pull than I need for my go-to fishing motor. Any ideas?

[dave-bernard]

do those starters have to be timed? I am a merc guy not OMC.

[wbeaton]

Did you use a Sierra impeller? They are taller than original and don’t fit properly. The thick impeller will make the motor hard to pull over.

Wayne
Upper Canada Chapter

uccaomci.com

[frankr]

Shock absorber in lower unit is broken and/or expanded. You disturbed it when you unbolted the pump

• This reply was modified 4 years, 7 months ago by frankr.
• This reply was modified 4 years, 7 months ago by frankr.

[amuller]

You could try pulling it with the plugs out to see if there is resistance from something other than compression. Some of these motors have a clutch-spring setup on the driveshaft for protection from prop strikes, and these can expand and create high friction. I think this feature begins in 1958 so should not apply to yours, but possibly worth checking.

This seems obvious but can you pull the motor with your other arm?

Others will know the smallest motors that have been available with electric starting. In OMC it was the 15/18 hp motors beginning around 1956. Likely different more recently. I *think* Mercury once made a 7.5 hp electric start motor. Honda and others make 8 hp electric motors but they are neither light nor inexpensive.

[fleetwin]

Like Frank says, that driveshaft shock may have expanded causing the driveshaft to bind on the upper bushing seal housing in the gearcase….Was the gear lube clean when you changed the impeller? I have never seen one of those old 7.5hps with such high compression….Usually see only 80PSI….So, I would recheck compression with another compression gage…. There is something unusual going on if the compression readings of 120-130PSI are accurate readings…
The 1955 engines did not have the oblong starter pulley, so “timing the recoil rope” is not necessary. Are you sure it is a 1955 model?
Wbeaton raises another great point about after market impellers, they are notorious for improper fit….Stick with the OEM water pump pieces…
That being said, did the engine pull over OK before you did the water pump job?

[The Boat House]

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• This reply was modified 4 years, 7 months ago by The Boat House.

[aquasonic]

The 54′ and 55′ Evinrude Fleetwins have the Simplex Starter and are just plain hard to pull, even when everything is set up correctly. If your motor has the original brown wire core starter cord, then there is virtually no stretch, and that makes it a little tougher on the shoulder. Nylon cord stretches a little, and is a little bit easier on the shoulder.

In 1956 OMC came out with with the Eas-a-Matic Starter. That is the elliptical shaped spool that has “cam action” and makes starting these motors much easier. They also have a larger pulley that requires more rope per revolution of the flywheel. The amount of work required for one flywheel revolution is fixed. If work is defined as force x distance, the more rope length per flywheel revolution, the less force is required.

So check out a 1956 or later 7.5 and see if that works with your shoulder situation.

[Parnold498]

Wayne, The impeller is the right fit – got it from a friend who repairs many old outboards (the local marina refers people to him).
spits out water well.

Frank, could be a damaged spring. Is it a hard to replace – worth it?

Amueller, I will need to recheck the compression. I think I might give the motor to my nephew and get an electric start. I’m not getting any younger, plus the doctor thinks I will need the same rotator cuff surgery on my left arm/shoulder.

Fleetwin, It is a 1955 model per serial number – the gear oil was slightly gray but pretty good. The motor did turn over before the new impeller, and it was just as hard.

Aquasonic – I will look for a newer, old motor and definitely look for an easier start – pull or electric.

Thanks guys for commenting. It ran so great once it got going so want to keep it.

• This reply was modified 4 years, 7 months ago by Parnold498.

[frankr]

The shock absorber thought came because that is the usual reason a 7.5 or 5.5 is hard to pull. But now the question arises, is it the motor or is it you? I dunno. But I do know that I just recently bought a new cordless electric chainsaw because I can’t pull the rope on my gas saw anymore. This from a guy that used to rope start the biggest V-4 outboards. Embarrassing, huh?

Anyhoo, if it is the shock absorber, that doesn’t automatically mean it is broken. They sometimes expand just from hard use. If it is just expanded, just mash it back together and run it another 50 years. But if broken some people weld them. My only attempt at that did not turnout well. Replacement is the other option.

Only an inspection can tell for sure.

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