Hey guys,

I'm after a decent mechanic for my 6hp 4stroke Suzuki. Have had a couple of mobile guys look at it, and even a Suzuki dealer. Still not happy with it. After a full carby clean and service, it still runs like a hairy goat. Latest drama seems to be that while it will start very sweetly, the moment I try to rev it (whether under load or in neutral), she just dies.

Very over it - everyone claims they've fixed it, then magically, it's crap again when I go to use it. Like yesterday, when I was trying to get on/off mooring in 20kts worth of wind. Full credit to my crew though - executed a near textbook pickup of the mooring knowing we didn't have the engine to rely on.

Boat's based in Birchgrove if that helps with suggestions.

Cheers,

Ray

Hi Plan.

I have had similar experience with my 2 stroke 3.3 Mercury. I was told by a mechanic NOT to drain the carby when
putting the engine away, and sure enough it fixed it. So, is it something as simple as that ?.

I know this sounds basic but have you changed the fuel? Because you might have a batch of crap fuel which is clogging up the newly-cleaned carby. Other than that it does sound like a carby issue.

Make sure you run the carby dry before you leave the engine for a period of time (i.e days, weeks, month, etc). This stops fuel from clogging the jets which is easy to do on small outboards.

Hey Flatty,

Yeh, full change of fuel when the mechanic cleaned the carby out on the 20th. The fresh fuel that was put in was NOT E10, but super duper premium.

To run the carby dry, I'd leave the engine running on the internal tank, but turn the fuel cock to the external one?

Would still like to know of a decent mechanic though - this is exactly the sort of thing I'm happy to pay for someone else to figure out - I just want to sail!

Yeah im not sure it has me stumped. A pain in the arse for sure. Sorry, i cant help with a mechanic.

Start from the basics. If you've had someone look at it, and cleaned the carburetor out, that's a start. However, before they did this, they should have done the following, in order.
1) Drain the fuel tank/s completely and make certain there is no water at all present. If there is, get as much out as you can, then pour in a litre of metho into your first fill. (Metho mixes with water and petrol)
2) Check the oil, if it is in any way dis-coloured, ie: Milky grey and not black/brown and clean they you have a water leak into the combustion chamber and that may cause a miss. This will require a mechanic to diagnose and repair.
3) Next, I'd change over the fuel line. If it's been sitting for a bit, or the line itself is old, the bulb may be deformed on the inside, causing a vacuum in the fuel line and a stutter or stall when you try to rev it. Also check the bayonet fitting and that it's not blocked.
4) I would then check the fuel cap, and that it's breathing correctly. (You did open the breather valve right?) If it isn't breathing correctly, it will cause a similar situation to a bad hose/bulb.
5) Check the spark plug/s, if they're very black it's not running correctly. Change them anyway. They should be a mid brown colour on the electrode, possibly a bit black around the top of the thread. If they're very white, it's running lean and will require a proper mixture reset. Same as if they're really black and gunky.
6) Check the spark plug lead/s and connectors. If the lead does come off the coil, clean and spray inside the connections with WD40 or a silicone water repellent.
7) You could also check the ignition/cut out switch to make sure it's got good contact. Hard to do without taking it all apart, but these can be known to break down on higher revs through vibrations.

Non of this is rocket science, and usually a simple fix. I find it difficult to believe a professional outboard mechanic wouldn't follow these basics to diagnose the issue from the start?

PM me if you still have issues and I may be able to help. NOTE: I'm not a qualified mechanic, but have lots of experience with my own Tohatsu 4stroke and motorcycles, where there's not a lot of difference. Also, I'm not on all that often, but do look in once or twice a week.

Thanks Michael,

Yes, I would've thought they'd do everything you mentioned - here's what was on the invoice;

Remove gearbox, remove and inspect or replace water pump impeller, remove propeller, grease
shaft, refit and refit gearbox to engine. Drain gear oil, pressure test box and refill oil.
Remove spark plugs, compression and spark test, gap and refit or replace spark plugs, drain
carburetor, remove and check thermostat, check throttle linkages and gear linkages for smooth
operation, check reverse lockdown and in gear start protection.
Grease steering and tilt mechanism.
Start and run engine, check water flow, set mixtures and idle speed as required.

When servicing the engine discovered water in fuel. Drained carby and removed fuel tank,
flushed and cleaned water out of fuel tank. Removed carby, stripped, cleaned and reassembled.
Refitted and tested engine in tank. Ran in tank, for 15 minutes working well.

It ran ok back over to the mooring that first day, but not since - I dunno if there's perhaps some way water's getting back into the engine while it's sitting on the back of the boat during rainfall or something? Deliberately haven't used the external tank since, in part because I don't trust the fuel that was in there in case the water was coming from there. This is all off the internal tank.

Really appreciate the offer of some assistance - I'll see when I'm next allowed out to play on the boat and check if you're available then!

No worries Planeray... If it's happening on both tanks, it could be a fuel pump issue? .... maybe? Curious. It may even be as simple as a perished fuel hose from the internal tank to the fuel pump, though they don't usually give you problems. The above mentions nothing about the fuel pump, or checking the fuel lines for perished internal sheathing.

I'm away over Christmas from 19th. But could possibly do a Wednesday arvo before then... but the weekend is already full, as I've not been to my boat since early October and I'm determined to get out this weekend.....

I found this fellow at 3 links; of course you may have already used him.

www.gumtree.com.au/s-ad/sydney-city/motorboats-powerboats/mobile-marine-mechanic/1195510202

www.facebook.com/HiTec-Marine-Services-1639698972931226/

www.truelocal.com.au/business/hi-tec-marine-services/punchbowl

He appears to be based at Punchbowl so not too far away from Birchgrove. Have never used him so cannot vouch for his work.

Hey all,

Small update. Watched a bunch of YouTube videos and did a bit of reading. Decided to go out and see what I could do myself.

Drained the carby bowl first, sure enough, there were a couple of blobs of what looked like snot in the first bit of fuel that came out. Lord knows what it was. For good measure, I completely drained the internal tank while I was at it, then filled it up with some fresh fuel to which I'd added some of this additive: www.whitworths.com.au/starbrite-enzyme-fuel-treatment-petrol-super-concentrate-29ml

After a couple of pulls, started up. At first, it didn't want to go past the start mark on the throttle, but I gave it periodic revs and soon it would do the full rev range! Dropped the mooring for a bit of a motor around. Varied throttle and it seemed ok...sometimes there was some hesitancy, but still an improvement. Even deliberately stopped and started it, seemed to go ok.

I think the next thing I might do is invest in an outboard cover in case I have a dodgy filler cap or something and I'll also try and keep the tank as fully topped up as I can (along with giving it more of a run than I usually do).

Select to expand quote

Planeray said..
Hey all,

Small update. Watched a bunch of YouTube videos and did a bit of reading. Decided to go out and see what I could do myself.

Drained the carby bowl first, sure enough, there were a couple of blobs of what looked like snot in the first bit of fuel that came out. Lord knows what it was. For good measure, I completely drained the internal tank while I was at it, then filled it up with some fresh fuel to which I'd added some of this additive: www.whitworths.com.au/starbrite-enzyme-fuel-treatment-petrol-super-concentrate-29ml

After a couple of pulls, started up. At first, it didn't want to go past the start mark on the throttle, but I gave it periodic revs and soon it would do the full rev range! Dropped the mooring for a bit of a motor around. Varied throttle and it seemed ok...sometimes there was some hesitancy, but still an improvement. Even deliberately stopped and started it, seemed to go ok.

I think the next thing I might do is invest in an outboard cover in case I have a dodgy filler cap or something and I'll also try and keep the tank as fully topped up as I can (along with giving it more of a run than I usually do).

Well done Planeray, always best to start with the basics.

You can get small filters for those internal tanks as well. Most spares shops have them. May also pay to change the fuel line, just in case there's some delamination or perished inner line.

Thumbs up!

Select to expand quote

Planeray said..
Hey all,

Small update. Watched a bunch of YouTube videos and did a bit of reading. Decided to go out and see what I could do myself.

Drained the carby bowl first, sure enough, there were a couple of blobs of what looked like snot in the first bit of fuel that came out. Lord knows what it was. For good measure, I completely drained the internal tank while I was at it, then filled it up with some fresh fuel to which I'd added some of this additive: www.whitworths.com.au/starbrite-enzyme-fuel-treatment-petrol-super-concentrate-29ml

After a couple of pulls, started up. At first, it didn't want to go past the start mark on the throttle, but I gave it periodic revs and soon it would do the full rev range! Dropped the mooring for a bit of a motor around. Varied throttle and it seemed ok...sometimes there was some hesitancy, but still an improvement. Even deliberately stopped and started it, seemed to go ok.

I think the next thing I might do is invest in an outboard cover in case I have a dodgy filler cap or something and I'll also try and keep the tank as fully topped up as I can (along with giving it more of a run than I usually do).

Make a point of buying non ethanol petrol from a garage with a big turn over.

Select to expand quote

Ramona said..

Planeray said..
Hey all,

Small update. Watched a bunch of YouTube videos and did a bit of reading. Decided to go out and see what I could do myself.

Drained the carby bowl first, sure enough, there were a couple of blobs of what looked like snot in the first bit of fuel that came out. Lord knows what it was. For good measure, I completely drained the internal tank while I was at it, then filled it up with some fresh fuel to which I'd added some of this additive: www.whitworths.com.au/starbrite-enzyme-fuel-treatment-petrol-super-concentrate-29ml

After a couple of pulls, started up. At first, it didn't want to go past the start mark on the throttle, but I gave it periodic revs and soon it would do the full rev range! Dropped the mooring for a bit of a motor around. Varied throttle and it seemed ok...sometimes there was some hesitancy, but still an improvement. Even deliberately stopped and started it, seemed to go ok.

I think the next thing I might do is invest in an outboard cover in case I have a dodgy filler cap or something and I'll also try and keep the tank as fully topped up as I can (along with giving it more of a run than I usually do).

Make a point of buying non ethanol petrol from a garage with a big turn over.

Yes never use E petrol, absorbs water like a sponge. Also fuel only last a short time now days, so use it or lose it!

Cheers Richard