merc 1967 9.8 110 model ,no water at exhaust port

[chiro757]

my 1967 9.8 110 model serial# 2145699. not getting water at exhaust port at back of motor. impeller replaced and working fine. removed flush screw and water was flowing great. motor running hot. no tell tale on this old motor. read that it could be blocked water tube or a grommet at powerhead. can compressed air be forced in at exhaust port. would it help to remove lower unit as to not get anying stuck in water pump. any suggestions would be helpfull. im new tio the forum. this a great way to get information. thanks for all who reply. have a great day.

 

[emckelvy]

Re: merc 1967 9.8 110 model ,no water at exhaust port

Pulling the lower unit off and blowing air (or circulating water) up the copper water supply tube will tell you everything you need to know. Your motor may be plugged-up and not getting circulation inside. You could pull the cover over the spark plugs and see what's going on there. Just be careful, if it's been in salt water you'll need heat on the bolts to get them loose.

BTW, are you in the water (or in a barrel) when you're running the motor? Otherwise not much water gets forced out of the exhaust relief ports.

Another good indicator of water circulating thru the powerhead is to feel the exhaust manifold cover with your hand while it's running. If much above lukewarm you don't have sufficient cooling to the upper end.

And yes, upper water tube grommets are a common problem, however, I'd think that if you get lots of water out of the flushing screw (I assume you mean the one right below the powerhead splashpan/cowling), water is at least finding its way up that far. However it's still possible to have obstructions to flow past that point.

Least invasive is to pull the back cover, so if you get an indication of poor flow when you run air or water up the water supply tube, I'd start with that cover.

HTH & G'luck.......ed

 

[chiro757]

Re: merc 1967 9.8 110 model ,no water at exhaust port

took lower unit off. forced air up copper tubing. plenty of air coming out of flush screw area but very little at exhaust area. since there in to tell tale where is the water suppose to exit. is it suppose to exit flush screw area. should i replace this screw. i will try water up copper tube see what happens. this plate you talk about is where spark plugs are correct. should water be seen there. thanks for your imput .im just a rookie with this older merc. have 5 other outboards and have never had any problems like this.most are in the 80's and 90's.

 

[Harker]

Re: merc 1967 9.8 110 model ,no water at exhaust port

Right next to the "flushing screw" is a small hole, that is the "telltale". On the 67 9.8, there is no hose, just a direct passageway from that hole to the bottom of the engine block. You could have a buildup of crud in the passageways. It is pretty simple to pop the powerhead off and clean it out. If you decide to do it you will need a new gasket that goes between the powerhead and midsection.

 

[chiro757]

Re: merc 1967 9.8 110 model ,no water at exhaust port

harker, thank you so much. i found the tell tale you mentioned and it is blocked completely. i will try and unblock it. hopefully i do not have to take off the power head. i have done enough today but will work on it next weekend. i was just about to sell it for parts. what awsome info. you just made my day. have a great day .

 

[Harker]

Re: merc 1967 9.8 110 model ,no water at exhaust port

My pleasure, I have a 67 9.8 and just popped the powerhead off and replaced outer gaskets so I was intimately familiar with what I told you..the guys on here gave me a lot of advice on motors so I am re-paying the debt when I can. Good luck with the old girl..I love mine.

 

[chiro757]

Re: merc 1967 9.8 110 model ,no water at exhaust port

cleaned telltale with weedwacker line. worked great. now having some carb idle issues. i keep trying to get this old motor going. thanks for the replys . hope it helps someone down the road. good fishing .

 

[Harker]

Re: merc 1967 9.8 110 model ,no water at exhaust port

Run a can of Sea Foam through it with about 2 gallons of 50:1 premix. Mine ran a lot better when I did that. Also, check all the old fuel lines for cracks..probably best to just put new lines on it..mine ran better when I did that..rebuild carb if it's been a while and check old gaskets for any signs of leakage.

 

[emckelvy]

Re: merc 1967 9.8 110 model ,no water at exhaust port

Try adjusting the idle mixture screw; the old 9.8's tended to be a bit finicky on idle mix, the 'sweet' spot (rich/lean) is pretty narrow.

Does it 'cough' or 'sneeze' (too lean), or is it blubbering (too rich)?

Something else to check is if you have the externally mounted fuel pump (somewhat rectangular pump on the Stbd side of the motor).

These are particularly sensitive to debris in the fuel pump check valves; it won't idle worth beans if it's not pumping enough fuel. Might run OK at higher speeds 'cause then the pump's pumping enough that the slight leakback doesn't matter. But it makes a big diff at idle if they're leaking.

You can dismantle and inspect but if you haven't serviced the carb I'd try that before tearing apart the pump. It's probably easier to get the carb's gaskets than it is to find a gasket/diaphragm kit for the pump.

HTH.........ed

 

[Harker]

Re: merc 1967 9.8 110 model ,no water at exhaust port

Old mercs.com has everything you need. I rebuilt my fuel pump with a new diaphram and check valves and I messed something up..found a brand new fuel pump on ebay that cost me less than the rebuild parts..put that on and works like a charm. The manual says to turn the idle screw out 1 turn from lightly seated but it takes at least 1 1/2 turns to start with. Be careful when rebuilding the carb, the cap over the float can snap pretty easy and can be a bit pricey to replace..it doesn't have to be torqued down very hard. Keep us up to date on your progress, I love these little Mercs.

 

[chiro757]

Re: merc 1967 9.8 110 model ,no water at exhaust port

thanks for all the tips guys. it runs for 5 to7 seconds then dies out. did get running for 5 min once then died. cleaned carbs. they were clean as a whistle. could be fuel pump. if i take the fuel pump apart what im i looking for. valves look like what when they are bad. i will try to take apart and i am sure i will be ordering a repair kit. i will keep you posted. again thanks for all the effort for trying to get this old merc going. im not gonna give up as long as i can get advice like i can here. i have other kickers that i use on my boat. i just love the challenge. just missed a carb and fuel pump on ebay.

 

[emckelvy]

Re: merc 1967 9.8 110 model, no water at exhaust port

Re: merc 1967 9.8 110 model, no water at exhaust port

There are 2 check valves in the pump; a check valve assy typically consists of a phenolic or metal disc which seals against the seat of the valve. Sometimes they're just a thin reed that seals against an inlet or outlet hole. If I recall, this fuel pump would have the disc-type.

"Trash" in the fuel can get in-between the disc and the seat so inspect carefully, and blow out any debris with compressed air or carb spray.

Also check the fuel pump diaphragm, it could be all stretched-out and so weak it won't pump anymore.

You may be able to pinpoint the problem down to the pump if, when you pump the primer bulb, the motor will keep running. This is a pretty good indicator of issues with the pump.

 

[chiro757]

Re: merc 1967 9.8 110 model ,no water at exhaust port

great info on fuel pump. i will try to clean it out and wait for the weather to break here in chicago. we are getting heavy wet snow. when it warms up i will try to get the this old merc going. i will post when that happens. this sounds like a soap on tv. maybe we should get a reality tv show on outboard motor repair. would be better than what is on there now. have a great day and good fishing.

 

[Harker]

Re: merc 1967 9.8 110 model ,no water at exhaust port

When you get the fuel pump off, you should be able to blow through the inlet side and you SHOULDN'T be able to blow back through the other way. My 67 had two little pipe shaped valves that had to be pressed out..then new ones pressed in to pretty exact measurements. I think I may have messed them up while tapping them in with a bolt and hammer. I bought the NOS one off ebay and it ran great. I'm about a 120 miles straight east of you and we got a lot of slop out of the sky today too.