Really basic engine questions

codprawn · 02 September 2005, 12:22

Never owned a small engine like this Suzuki 15hp 4 stroke before - great little engine but no manual - bloke had lost it!!!

Really need the manual for it - can anyone help??? You can download the Yamaha one as a pdf no probs but NOTfrom Suzuki/Johnson. I phoned 4 Suzuki dealers who either didn't answer the phone or just didn't want to know!!!

Had 2 little probs with it yesterday - 99% of the time it was great but it did worry me once.

On the way back suddenly lost a lot of power and seemed to run hot with a funny noise - loads of steam coming out of telltale. Shut down quick - noticed a clump of weed around the skeg but it soon drifted off. Waited a few minutes and restarted fine - good telltale - power still WAY down for about 2 mins and then - suddenly - off we shot!!! Could it have gone into limp home mode for a bit due to lack of water???

2nd Question - occasionally got a load of cavitation - only briefly and then it would be ok again for ages - wonder if it could be the motor isn't low enough in water - no electric trim of course!!!

I am not sure if the engine was tlited down properly - I know there is a reversing lock and the outboard should be free to kick up if you hit something but I am not sure if I am doing it properly - should the little lever at the top front of the saddle be pushed down so the leg will tilt down further???

Pete7 · 02 September 2005, 12:27

Quote:

Originally Posted by codprawn

On the way back suddenly lost a lot of power and seemed to run hot with a funny noise - loads of steam coming out of telltale. Shut down quick - noticed a clump of weed around the skeg but it soon drifted off. Waited a few minutes and restarted fine - good telltale - power still WAY down for about 2 mins and then - suddenly - off we shot!!! Could it have gone into limp home mode for a bit due to lack of water???

Nope, you have seized it mate. Don't worry had a trial bike that used to do it regularly, that was a suzuki too.

Quote:

I am not sure if the engine was tlited down properly - I know there is a reversing lock and the outboard should be free to kick up if you hit something but I am not sure if I am doing it properly - should the little lever at the top front of the saddle be pushed down so the leg will tilt down further???

Suzuki played around with a shallow drive lever for a while on some outboards, sounds like this is what you have.

Pete

Pete7 · 02 September 2005, 12:33

Ah, just noticed its four stroke, heavy horrible noisy gutless things, never had one. Flog it quick and buy a nice 2 stroke

codprawn · 02 September 2005, 12:44

Quote:

Originally Posted by Pete7

Ah, just noticed its four stroke, heavy horrible noisy gutless things, never had one. Flog it quick and buy a nice 2 stroke

Got a nice 2 stroke - Suzuki 225efi

Pete7 · 02 September 2005, 12:45

Thats more like it

hannah · 02 September 2005, 16:23

whats so good about a 2 stroke may i ask ? i always thought 4 strokes were better

codprawn · 02 September 2005, 16:28

4 strokes give you more low down torque and are more efficient - 2 strokes are smoother and have better torque higher up the rev band - so basically fast boats are better off with 2 strokes!!!

gavin · 02 September 2005, 17:22

Check the little bar type pin on the transom bracket, to see if the engine can tilt down more, I am not sure if the motor has the ability to run in slow mode if you get an overheat ,I am doubtful due to its size, as regarding its power loss, check fuel line for kinks, obvious stuff like air vent on cap ,or loose connecting fuel connector, you will get a noise as motor starves of fuel ,may explain power loss , is the filter empting quicker than it fills, or fuel hgose too small.
I am sure you just got an overheat with the intake blocked

gavin · 02 September 2005, 17:26

Hannah four strokes are normally heavier, dont rev as high, a little more complicated, have a sump of oil, valves camshafts , oil filter and produce power over 4 cycles
Two strokes no valves, great immediate power delivery, mix oil with fuel in the combustion chamber, are lubricated differently, a bit more revy and I think if you exclude fuel injection, a little simpler

Fuel efficency, boat size and weight,purpose for boat , running costs will all determine whether you go 2 or 4 stroke

codprawn · 02 September 2005, 17:54

Quote:

Originally Posted by gavin

Check the little bar type pin on the transom bracket, to see if the engine can tilt down more, I am not sure if the motor has the ability to run in slow mode if you get an overheat ,I am doubtful due to its size, as regarding its power loss, check fuel line for kinks, obvious stuff like air vent on cap ,or loose connecting fuel connector, you will get a noise as motor starves of fuel ,may explain power loss , is the filter empting quicker than it fills, or fuel hgose too small.
I am sure you just got an overheat with the intake blocked

The tilt pin has only one hole left to go - checked all you mentioned - no problems - it was really sudden and then 5 mins later it was fine!!!

I know the Yamaha will go into limp home mode if it has low oil pressure but not sure on an over heat - anyway mines a Suzuki.....

Thanks for the help though!!!

PeterR · 02 September 2005, 18:20

Hi codprawn,What you really need is the home phone number of a good marine macanic so when it goes wrong you can desribe symtoms as they happen Its a bit like a policeman theres never one around when u want one