Outboard Motor Woes (8hp, 2 Stroke)

[mr-canada]

Thanks for looking into this post. I write this here halfway in the middle of my two week vacation whereby i *intended* to do some coastal cruising and gunkholing on my second year having a sailboat. Second year was not as kind to me as the first year... At the start of the season my forestay snapped, i was lucky it happened at the dock. Got that fixed and the kid had had surgery so my girlfriend could not come out to the boat and buddies bailed at the last minute or were working weekends, didnt want to test my third party liability insurance getting in and out of the slip, winds here are often 20 knots so i need a fender on the bow.

During one of these aborted attempts to get out on the water realized the motor was not spitting water. No engine cooling means no go. I tested with a garden hose to see if it was blocked and it wasnt so i got a new impeller in time to install it first few days of my vacation.

Got the engine apart, installed the impeller, tested the driveshaft was properly in place by turning the prop and watching the flywheel. So far so good.

Got it back on the boat to start it and it ran great great stream of water coming out. Problem solved. Except it would not engage into gear, shifter moved free like it wasnt connected to anything.

Motor back off the boat, figured out that the nylon clip that attaches the shifter to the gear linkage had popped off somehow. Tested the shifting. Clicked into foreward, reverse, neutral. Figured now i was all good. Didnt even have to remove the lower leg again, yay.

Motor back on the boat. Started fine, impeller still working, good water stream. Forward worked, reverse worked, i figured yay im in business.

Girlfriend came up to the boat we bought a thousand bucks worth of gas, liquor, supplies. While my boat wasnt operational a buddy at the yc took me fishing and it was a great spot i bagged 2 salmon in 15 minutes. Me and the girl decided maybe to head back there spend the night fishing, try to bag the limit then pop the sails up and head out, at least then we wouldnr have to worry about the tides in the shallow channel we have to escape from.

As im leaving the slip, realize that mr. Motor is not at all ok. Almost hit a boat because i backed out and when i popped it into forward, then gave it a kick of throttle to get me going forwards, it popped out of gear and started revving wild. Dropped the throttle, put it back in gear and tried again to kick it to get me moving forwards, same thing. I managed to escape hitting anyone and started on our journey.

Was getting late and the log boom i expected to tie off to at he fishing spot was gone, had to turn around. It was sunset i do not have adequate night gear so had to get moving. Same problem, more than 30% throttle it would pop out of gear. Made it back just before dark with the assistance of the lightng at the docks.

With the motor doing his me and the girlfriend decided to play it safe (well i decided) and maybe just do some daysailing and fishing and hang out aboard at the docks, im moored in a small town outside of the city so fine.

Go out for a fishing trip in the daytime, start backing out of the slip, realize that i cannot increase the throttle in reverse beyond idle. I think quick and adjust the idle speed to get out of here safely. Shifts to foward ok and throttle works then so off we putt slowly and do some trolling since i cant exceed 2.5 knots under power anyway.

At the dock i test the throttle in reverse problem. Like clockwork, every time in reverse throttle wont turn. Test giving it some power forward and reverse and every time it pops out. I tried firmly holding the shift lever and that seems to keep it in gear but hardly a solution given its mounted on the transom and an awkward reach.

Apparently the seller of my boat had pulled this motor off of the bottom by a few of his diving buddies and restored it 6 or seven years ago. This is my second vacation screwed up by this motor, last year it was making a rattling noise and i ended up paying a mechanic $400 to travel all the way here because there arent any in this town. I made it back with $5 in my pocket at the end of that trip due to that unexpected expense, there was no wind and i almost completely ran out of gas 4 hours from my slip, i had to just pop the sails and do what i could. Ohh the joys of travelling at 1 knot because you couldnt afford to buy any more gas along the way due to repair costs.

Im no mechanic but im willing to try anything. I think this motor was at the bottom of the bay for a reason and i might just return it to a watery grave. Unfoetunately i cant afford to buy another one until long after boating season is over in december so this cursed **** is all ive got for now.

Also im worried that every time it pops out of gear its grinding something that will only make the problem worse. I dont want to be stuck without power on the water in this place with consistent strong winds. I can try to sail in on an inflow, but without sails up and motor in idle reverse i still have a problem dropping speed.

Sorry for the long winded tale... Any ideas? Ive got 7 days of my vacation left and maybe two or three more weekends and ive only made it out for a few very short trips between all these issues. My gut tells me the lower leg of this thing needs to be rebuilt and its only going to get worse, but i know little about outboards.

[pbiJim]

Originally Posted by mr-canada

Apparently the seller of my boat had pulled this motor off of the bottom by a few of his diving buddies and restored it 6 or seven years ago. ...

...I think this motor was at the bottom of the bay for a reason and i might just return it to a watery grave. Unfoetunately i cant afford to buy another one until long after boating season is over in december so this cursed **** is all ive got for now.

Also im worried that every time it pops out of gear its grinding something that will only make the problem worse. I dont want to be stuck without power on the water

Being on the bottom isn't good for any motor, but if it was fixed up & ran well for a season, then the time that it spent on the bottom probably isn't the cause of your current problem.

It sounds like you have a shift linkage problem. It sounds like the shifter isn't pushing the gizmos in the lower unit all the way into either gear. Maybe the shifter isn't moving as far as it should. Maybe the linkage that you reconnected is either bent or worn.

In any event, that grinding sound that you hear is probably the dogs in the lower unit getting chewed up. If you keep running like that, you are going to loose all motion & have very expensive repairs ahead.

Linkage problems are usually quick, cheap & easy to repair. Problems with the dogs are not.

If you do not understand how the shift linkage is supposed to work, then find someone that does & have him look at your motor before you leave the dock again.

[sy_gilana]

Mr Canada, I can help you if its a Yamaha. Please tell me it is...
The throttle to gear position sync needs adjusting, simple as that!
It all started when you dropped the leg, you were supposed to disconnect the shift control rod, did you? if not, you've probably broken something plastic inside the motor...
Please send email to let me know you have answered if its a Yammie...

[FSMike]

Some motors are designed so as to restrict the amount of throttle available in reverse. If such is the case with yours, a misadjustment could result in no more than idle speed available in reverse. These restrictions/adjustments are usually under the engine cowling as part of the throttle linkage.

A similar misadjustment with the shift linkage could result in the engine popping out of gear in forward. Have you tried holding the shift lever in place while revving it up in forward? If you can get it to work that way, I would think a linkage adjustment might solve the problem.

The good news is there is a mechanic available in your area. The bad news is it's you. Get an owner's manual, a shop manual. and some tools. You can find lots of how-do-I-fix-this-damn-thing info on the internet.

Last but not least, you say you aren't equipped for night time travels. I suggest you get equipped. Problems can happen to anybody anytime, usually, as Murphy decreed, at the most inconvenient moment.

[mr-canada]

It is a mariner. However mariner was a trade name for small engines built by yamaha for mercury. So it is sort of like a cross between a mercury and a yamaha but more japanese than american.

I did not remove the shift linkage when dropping the lower leg, i let it hang there while i worked, propping it up on a milk carton.

When the shifter stopped working altogether i found the plastic part that holds the linkage to the shifter and reassembled it so now it goes into gear.

The new problem is it popping out of gear at higher loads and this weird thing with it thinking its in neutral when its in reverse and restricting the throttle. It didnt even do that in neutral before but i know that is what this feature is for. (it is not on a remote, still has the arm).

There is no mechanics here and my mobile guy just got married - plus just getting him here and back runs me $200 in travel. I was texting him to see if he knew what was maybe going on he suggested a gear linkage nut that doesnt exist on this model (i give him credit, its been over a year since he looked at the motor) and he says he has a great low maintenance long leg 4 stroke i can take off his hands for $1500, just i cant grab it until i bonus out in the late fall so i have the cash to pay for it.

Thanks for any ideas you might have. The rum is flowing and im eating like a king trying to make lemonade out of this lemon but id rather be going somewhere other than walking the docks in my yc marina

[mr-canada]

Fsmike: holding the shifter in place seemed to help the problem as i mentioned above

[pbiJim]

Googling around, I found this -
Mariner 8hp outboard manual - free eBooks download

If you go here -
http://www.usboatsupply.com/Mercury_...og3a.php?mc=02
You can find exploded diagrams by model # & year

I think that they were made by Yamaha up until the late 80's, then I think that Merc started to make them in-house.

The Merc built ones should have a freeze-plug looking thing on the starboard side that has a serial number on it.


More interesting reading:
http://boatinfo.no/lib/mercury/manua...-99-10-15.html

http://download.brunswick-marine.com...egories=&mod=4

[sy_gilana]

Ok The Mariner and Yamaha are very similar.

In order to explain the problem, let me say what you should have done to change the impeller.
1-take out kill switch
2-select reverse gear
3-remove rubber cover in leg (or find adjustment nut at bottom of swivel bracket)
4-release locknut
5-undo adjustment nut counting the turns or flats
6-drop leg change impeller etc, and reverse order 5-1 above.

By letting it hang on the control rod, you might have bent something but lets work around that.

Tools: Flat screwdriver, 2 x 10mm wrenches, long nose pliers, flashlight.

Identify location of adjusting nut, it is either behind a rubber cover lower on the leg, or it is peeping out of the leg just behind the swivel bracket at the lower part. You must find it first.

By pulling on the control rod, you might have pulled it out of the lower unit too far and there could be oil leakage, or worse, water going in to the gearbox. It would be wise to re-do the dropping of the leg to check that the rubber seal that the control rod goes through is intact and in place (Expensive if you don't check)

SO to remove the whole shebang again please follow these steps.

1-remove kill cord
2-remove rubber cover or find the adjusting nut
3-select reverse (as best you can)
4-slack locknut on adjusting nut and undo adjusting nut till its free.
5-undo the 4 lower unit bolts
6-ease away the lower unit completely

Using flashlight, check that the mechanism from the shift lever is operating the square shaft, and the plastic cams. Check that the detante spring is able to click into 3 positions r-n-f. Check that the washer and splitpin are in place to prevent the hooked end of the shift rod unhooking from the cam. Return the shift lever to R.
Check the condition of the seal where the shift rod enters the gearbox, if all OK then

7-coat the water pump rubber grommet where the water delivery pipe connects with grease, taking care to not block the pipe.
8-look up the leg to identify the location of the water delivery pipe and that it is not free like a pendulum but retained more or less center.
9-coat the spline at end of driveshaft with grease
10-offer the lower unit up gently, no force is required, feeling for the waterpump to engage the delivery pipe.
11-the spline should now engage, rotate the prop by hand to align splines.
12-close the gap, and place two opposing bolts in and hand tighten
13-place the other two bolts, and only tighten if you can shut the gap by hand pressure only, if so, tighten to spec.
14-Now, the lower unit is in reverse still, and the lever is in reverse.
15-Screw the adjustment nut onto the shift rod, it should be at least 1.5x diameter inserted
16-place shift lever in N try to rotate prop, it should rotate freely without any clicking.
17-select F - try to turn the prop backwards, you should not be able to, but there should be clicking if you turn it forwards
18-select R - try to turn the prop forwards, you should not be able to, but there should be clicking as you turn it backwards.

By feeling at the prop where the "sweet spot" in between the F and R positions is, you adjust the nut until that spot occurs when the shift lever is in the vertical position. So let me put it another way, one hand on the shift lever, the other on the prop, moving the lever and feeling the prop, find the true neutral at the prop, and then see where the lever is. If it does not agree then adjust the nut so that it does.

Normally you would count the turns, or insert it a specified amount, but you have to "feel" this one, as the kinks in the shift rod might have been pulled out of spec by hanging it while you did the impeller.

Question....how did you get the impeller off the top of the driveshaft if you never pulled it right out?

Hope this helps, now I am in SH12 for hogging the computer while my wife wanted to go online...

[mr-canada]

Tried your ebook link but they want a credit card , odd for a free download. Not your fault you probably just found it using search. The parts place might have the part but i need to figure out if/what part i need.

Thanks for your help though, its appreciated

[mr-canada]

Sy_gilana

I will have to try your suggestions tomorrow when its light out. Power down here at the docks is cut because a major power transformer blew so no artificial light even.

Few things though

Your steps.1-5 i think wouldnt be possible on this motor. Heres how i did the impeller

1. Undo the three bolts holding the lower leg in place
2. Let the lower leg slide down exposing the impeller housing
3. Lift the driveshaft out of the lower leg, get the lower leg out of the way and drop the driveshaft out of the powerhead
4. Take the impeller housing cover off and pull off the shredded old impeller
5. Place the driveshaft back into the lower leg and put the key into the groove on the shaft
6. Lower the impeller down the shaft until it slipped over the key (grease new impeller)
7. Put gasket maker around impeller and drop impeller cover back on
8. Carefully raise lower leg into the powerhead ensuring the driveshaft and tube for the impeller to push water up line up and connect
9. Turn prop or flywheel to ensure driveshaft is engaged
10. Replace 3 mounting screws for lower leg

What i missed that i now realize was to remove the nylon tab connecting the shifter to the gear shifting rod (so i could drop the whole assembly to make changing the impeller easier rather than doing it with the lower leg hanging by the shifting rod)

When i was messing with the linkage connecting the shifter to the gear shifting rod i did not see any notches or adjustment screws under the cowling. I wasnt looking for one though i was just trying to get the shifter moving the rod again, but i was looking pretty close as it was a trick to figure out

[pbiJim]

Mr Canada, can you identify the year & model number of your particular motor? There are different versions. You & the very helpful Mr. Gilana may be talking apples & bananas.

[mr-canada]

There is no serial number plate with the year on it. I beleive it is an 80s model mariner 8hp made by yamaha

[MarkSF]

On my 89 Yamaha 2 stroke, the shift rod is in two parts, an upper one attached to the throttle arm, and a lower one attached to the lower unit. They are held together with a metal block with a screw through it.

The block is 28/29, and the screw is 30 :

1989 8SF Yamaha Outboard CONTROL ENGINE Diagram and Parts

and the lower unit rod is 52/53 on this diagram :

1989 8SF Yamaha Outboard LOWER DRIVE 1 Diagram and Parts

The two rods have to be in the correct relationship for the shift to work. It is possible that they slipped relative to each other, while you were hanging the lower unit from them.

The fix would be to loosen the screw (30) and adjust the rods. They simply slide up and down inside the block, so you can adjust them.

The plastic clip operates the reverse gear / tilt interlock, which is a separate issue.

[mr-canada]

Interesting. My shift lever goes on a bit differently, the plastic tab I put on is what holds the shift rod heading to the lower leg, in that diagram there is a screw. I will look for a different action heading to the throttle arm

[sy_gilana]

Hi Mr Canada, Obviously we are talking two different motors. The 8 Yamaha has 4 bolts to the lower unit, sorry I could not be of more help to you. The principle remains though, adjust the rod to sync the lever with the gearbox.