'73 Johnson 65 Surges at Higher Speeds

[little mfg]

If you recall, they weren't warped. I only had to clean them up. I'm fairly satisfied they should be ok, but you never know. I have read though that bolts need to be retorqued after an initial break in. If I need to remove the exhaust manifold again, I will---just wish there was a way to do it without pulling the power head. I think I'll pursue some of your other suggestions first, oldboat. This boat sat for 10 years. I think it'd definitely be worth going over the carbs. Does your WD 40 procedure work for around the exhaust manifold as well? Thanks!

 

[oldboat1]

Procedure should work on the cover -- but take care (gets hot). Maybe the retorque is all you needed. Doesn't hurt to be optimistic.

 

[little mfg]

Yes, sometimes I'm hopelessly optimistic :clock:

 

[Tailhook]

I had similar symptoms with an inboard/outboard years ago..would idle fine...get up on plane and immediately start sputtering ....throttle back and would struggle back to a normal idle. The fuel tank pickup tube had a screen on it that was partially blocked with a gray residue ....moisture and fuel combination I assume . Also check the check valve on the fuel pickup tube for proper operation if it has one.

 

[little mfg]

Ya know, Tailhook, I think I'll take a look at that! Thanks!

 

[jimmbo]

Usually an Exhaust Leak makes itself apparent quicker than a minute when the cowl is on. See how it runs with retorqued boals. If it is still losing power, try running with the cowl off. I'm having a feeling of Deja Vu right now

 

[little mfg]

Hey Jimmbo, I need some extra education here. Are you saying the cowl might be restricting airflow to the carbs? The vent appears to be unrestricted. Thanks!

 

[little mfg]

Regarding the primer bulb... is it supposed to be constantly hard? It does get soft while running, but pumping doesn't make any difference in the motor's performance. It keeps surging. I can feel fuel inside, tho. Thanks!

 

[jimmbo]

If there is an Exhaust Leak, the cowl will fill with Exhaust and the engine will inhale it. When the cowl is off there is much less chance of that happening

 

[little mfg]

Now I gotcha. Thanks! I'll look into it!

 

[little mfg]

Hi Everyone, here's the situation. The good: I discovered some seepage at the primer bulb. Removed the factory clamp and replaced it with a screw clamp. Nice and tight now and bulb stays hard. Now for the bad: The top left manifold bolt won't torque down causing water to spit out the top out of the top cover. The ugly: I hadn't mentioned this before because I thought I had it licked. The top left bolt was the only bolt that broke during the initial tear apart. I retapped and installed a helicoil. It ain't workin' and won't hold enough torque to keep the cover from leaking. So off with its head again I concede now the cover's warpage identified earlier can't be repaired. I don't think there'd be any material left after honing, so I will buy another one.

Now I have a couple new questions. What should I do to fix the hole with the helicoil? I plan to remove it, but then what? Also, there are two type of covers. A new style with some extra reinforcement, and the original style. See pics, below. My motor is model 65ESL73. Will the newer style work, or should I stick with the original style.

As always, thanks so much for your advice. You people are a wealth of information!

PS, I see now there are three styles of covers. I am attaching a photo of this style also.

 

[jimmbo]

What are the 'new style' covers off of?
Regarding the HeliCoil... Did you use the wrong one? if so, perhaps you can locate a bolt/stud and nut of the proper thread. Another Option, if there is enough metal, is to remove the HeliCoil, drill and retap the hole for a bigger bolt

 

[little mfg]

Hey Jimmbo, the one ebay description sez this: [h=1]390041 317217 Johnson Evinrude 1972-1988 Exhaust Manifold Cover 60 65 70 75 HP[/h] The other ebay description sez this:

[h=1]0329834 0343864 Evinrude Johnson 50-70 Hp Outboard Exhaust Manifold Cover[/h]

My part numbers for motor 65ESL73R, according to MarineEngines.com that has inventory sez this:
0317217 - Exhaust Manifold Cover
0390041 - Exhaust Manifold Cover

But the casting number on the cover that matches up with the first ebay numbers (which match up with marineengine.com) sez 323087.

Hence the confusion on my part! It may be best to just stick with the cover that looks identical, but if I could get a beefier version that works, that would be even better.

Thanks

 

[racerone]

Perhaps the one cover is off the 56 cube block,.-----It does have the hole for the telltale fitting.

 

[little mfg]

Thanks for the response, racerone. Would you have to know the cubes on a '73 65 hp?
Thanks!

 

[little mfg]

Btw, I noticed that hole and wondered what is the purpose of that hole?

 

[racerone]

It is 49 cubes.----Well maybe a bit more. ---Not over 50 cubes.

 

[little mfg]

Gotcha. Thanks!