Petrol engines......arrrgh

[Rich_S]

I tried to catch attention with the post title but I do have a serious question:
My car is a 1987 Fiesta 1.6S and I don't do anything to it except top up the oil when the red light comes on when I go round a roundabout. My boat has a 1990 5.0l engine that I lavish nothing but care on, replaced points with breakerless ignt, new fuel and oil filter every season, tune up, new plugs, this season new leads as well. The last trip it didn't get full revs. BTW same care lavished on outdrive......apart from everything else 160 quid on refurbishing duoprops plus me stripping leg back to bare metal and repainting.
Why then does my car start on first turn after 2 weeks of inactivity and the boat don't? They are both basic engines, no EFI, and my car still performs, albeight in a puff of smoke (we've been expecting you Mr Bond).

As an aside and hopefully not a diversion, how do you get to afford a 23M???

Regs...........Rich

 

[jfm]

Re: you\'re spoiling it!

Could that be it, TOO MUCH care and attention? Wot if you treated it like the Fiesta?

I guess from your post it's a Merc or Volvo. I bort a brand new Merc 90hp outboard on 27 Jan 1981. I put it on a boat in a summer house in Ireland. I used it twice a year in saltwater (6 weeks use/year, but praps 3-5 hour running most days), and hosed it out with freshwater then stuck it in the garage. I sold it 6 mths ago. In the whole 20 years I only ever changed the water pump impeller twice, gearbox oil every 2nd year, wiped the plugs, greased the nipples, sprayed WD40. That's all. I never changed the plugs, HT leads, never ever took it to a dealer for service or anything else, never adjusted the carbs, never bled the hydraulics, nothing. I even changed the boat. It never failed to start first time, it ran like a sewing machine (6cyl) right up to the day I sold it.

Not sure I recommend the above, it's non compliant with the manual but it's engineeringly sound. Often the level of use is so small that if you just lubricate them and stop them corroding away that's all you need?

The maintenance schedules are sometimes designed to support the service industry. We took our merc 5hp to a dealer (in a moment of pecuniary madness and laziness) for it's first annual service last year. It had run 2 hours max on the tender (we're Solent based), they insisted on pulling the gearbox off and changing the water pump, becuz it says that in the official service bulletin. Cost £75, more than the Merc 90hp cost in 20 years!

I'm not recommending neglect, just giving alternative view as food for thort.

JFM

 

[DepSol]

checked your fuel filter and lines? Changed where you get your fuel from or the spec of your fuel changed? Look at the colour of your plugs. Most engines and partly because of the fuel type have the same plug for cylinder no.1 to 4,6 or 8 where in fact sometimes as you go along the cylinder no's the grade of plug could do with changing. Give it a good warm up & run, bring it back in and check the plugs make sure you've replaced the fuel filter first of course!!

Let me know the colour variations.

 

[jfm]

Re: Why??

Depsol never heard that before. I assume you are saying that different combustion is happening in the different cylinders, and hence different plugs should be used to suit. Why is that? I mean, why should wot's happening in cyl #1 be any different from wot's happening in cyl #2 ?? The only difference I can think of is a slightly different shaped inlet and exhaust tract for each cyl, which might change the mix slightly. But everything else should be identical. Is that it?

Hey, that's the first post in which you didn't recommend Soltron )

JFM

 

[ChrisP]

Re: you\'re spoiling it!

Got to agree with your system. It's always worked for me. Biggest problem with petrol engines is that they are primarily land bassed designs put into the worst conditions any engine could have in it's worst nightmare. Outboards are designed for the environment and therefore tend to have less problems dealing with the damp etc. My advice is to keep them dry and clean.

 

[DepSol]

Re: Why??

ok, but this doesnt actually effect outboards that much, you get different heat ranges across each cylinder therefore to combat this you use different heat range plugs for each cylinder. because they are lined up and water flows from one end throught to the other everything is marginally different. It is very difficult to set up this way but proffesionals will kow what to do especially people who know the different grades of plug. It is hard to explain but it is a well known fact. For example why does the last cylinder in a flat four always have a slightly lower reading on a cold compression test?

Its the difference between following the manual and being spot on. folwing the manual ensures it works being spot on ensures that you get that little bit of better performance and responce also your engines run cleaner more efficient and have less wear and tear. (vibration in boats especially is a killer)

The only reason I mention Soltron so much because it is a good product. People take fuel from the pump for granted that it is the correct Octane number and it is clean. Different fuels burn differently and the only way to ensure they burn at the maximum ROHR (Rate of Heat Release) in the combustion chamber is to add a product that will do this.

 

[Guest]

A common fault with any petrol engine is ,once the engine is hot the heat can heat sink into the carburetter causing the fuel to expand .This can look like the needle valve is sticking allowing the float chamber to flood .
When the engine is turned off the fuel pump wont compensate for the lower fuel level because the fuel firstly expands ,then cools down leaving a lower fuel level.
Also the petrol will evaperate when not in use as well as leaving salty type deposits in the float chamber and jets .
So if your engines fuel pump has a priming lever try a few pumps to get the fuel level at the correct height .
Maybe your fuel lines have an air leak which although the fuel does not leak out the joint can suck air in !!.
Be very careful re having different plug grades in the engine because it will make the engine run uneven and lets face it if the manufacturer after all the testing and development of an engine dont have different plugs nor should we !!
Personaly I prefer an engine to turn over a few times before starting because the oil pressure gets a chance to build up .
cheers mick
http://www.carburetterspecialists.fsnet.co.uk

 

[Guest]

Re: Nail it!

Cars do, say, 12000 miles a year at average 20-30 mph. That's 400-600 hours. At 20,000 miles/year that's nearer 30 mph average, so 700 hours. Much more useage that a boat. If you go on a long trip (3hours or more) it will be lovely for the engine. Also, most cars are in nice dry areas, not salty damp nasty coast.

As to your other question, please let me know if you find an answer.

 

[Guest]

Thanks for the tip about the red light, I wondered what that meant, all I have to do now is find out how to open the bonnet.

In reality, we all know that modern cars don't really break down and if they do, you just coast to a stop and call the AA. Not quite so easy in a boat though is it? And how often do you run your car at 4,000 rpm for hours at a time, with no variation in speed or load etc. As the others have said, it's also a harsh environemtn that the engines aren't really designed for.

Course it couldn't have anything to do with the fact that messing about on boats, even mucky engines, is more fun than shopping with 'twife at Tesco's etc could it?

 

[KevL]

"And how often do you run your car at 4,000 rpm for hours at a time"

Well now that you mention it quite often ..... Especially on Mondays and Fridays.

Kev - EvilKontractorSkum

 

[Guest]

"Well now that you mention it quite often ..... Especially on Mondays and Fridays."

Somewhere near your left knee, assuming it's a right hand drive car, you'll find a gear lever marked R, 1,2,3,4 and 5. Try moving into fifth and I bet even at 80mph, you'll see the revs drop down to around 3,000. And for hours at a time? On Mon and Fri? where do you live? There's more traffic around then than you can shake a gear stick at and if you can keep to those sorts of speeds for any length of time, you're not anywhere I've ever been. Ah but then you're a Manwegian aren't you? Don't you have traffic jams up there?

 

[Geoffs]

Re: Another reason..

different cylinders behave differently is down the way the carb is installed. On a bank of 4 cyls the carb usually sits on the inlet manifold over cyls 2 & 3. This means 2 & 3 get more fuel that 1 & 4. That's why on a high performance 4 cyl engine you used to have twin carbs. Multipoint fuel injection gets round this. Some 3 cyl outboards have one carb per cylinder .

 

[Guest]

You girly colin. 4000rpm is a nice steady 120 on empty french motorway. I think some of these boats could do with a damn good thrashing.

 

[longjohnsilver]

Thrashing

Do you mean a la Basil Fawlty. That didn't get his car to go so why should a boat engine be any different - also less trees at sea to tear branches off. I did however see a floating freezer 2 miles off Sidmouth today!!!

 

[Guest]

Re: Thrashing, and Whirlpools

No, not that sort of thrashing. I simply meant that an engine run at some speed (not tickover) for a good long time - perhaps several hours, seems to run much more sweetly. For some engines in small crusinig areas, I don't know if they ever get this.

 

[Col]

Don't know what boat you have, but if you keep it afloat, make sure the hull/drive/prop is clear of marine growth and or damage.
You could have a missfire which can be hard to detect on a V8. Recheck your plugs + leads, also make sure choke is not staying on. Finally, if its a Volvo with power steering,make sure the flame arrestor (air filter) on top of the carb isn't blocked (the power steering pump is driven from the water circulation pump,the drive belt struggles to drive it all,the belt slips and the flame arrestor gets blocked with black fan belt dust)Good luck!

 

[KevL]

Ah Ha so thats what that little stick is for then, and I thought it was there to hang my wifes handbag on... well you live and learn ;-)

But seriously, BMW Z3 1.9 at 4000 RPM = 90ish MPH and yes before you start I already know it's a girly car. As for being able to do this for any length of time, it's easy at 4:30 - 6:30 on a monday and after 20:00 on a friday. Perhaps sitting in traffic jams is a favorite pass time for soft sothern shandy drinking jessies <G>

Kev

 

[BarryD]

Well, Thanks Colin this info was so handy - I tried it at the weekend on my "stable".

1. Wifes Car - Got to 3,000RPM lost nerve she never goes this fast.
2. Stag (Auto) - Cruised at 90MPH, no issues.
3. TR7v8 - 4,000RPM = 70MPH, OK need to look at the final drive ratio
4. Jeep (Auto) - 95MPH held it for two hours, got exciting near Southend
5. Borrowed boat - 30MPH (I want this boat)
6. Lawnmower - Held for 20secs and ruined the flowerbed. Engine now rattles and my voltmeter / rev-counter is a bit melted (whoops).

Barry D.

 

[Guest]

Re: 4000rpm =max cruise?

On petrol engines, someone said that for "maximum crusing speed" it usually "felt about right" at 4000 rpm. Which is evidently quite quick on some cars...

 

[Rich_S2]

Re: 4000rpm =max cruise?

Gents,
thankyou for your comments. I like the sound of a good thrashing and am already formulating another trip. What are your thoughts on running for long periods at 3500 rpm which is all I am getting when the engine should reach 4300. Hull and leg are still relatively clean. I am concerned that I could damage something.
One other point is that I live in the UK where the land is as wet as the water in my opinion. My car sits above and has to drive through great dirty puddles. Is the air adjacent to the Thames really that much more humid than the air we get in say London?

Rich.