suzuki DF2.5 compression?

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DogWatch

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Does anyone know a ballpark figure for a suzuki DF2.5. Or an exact figure. The workshop manual I have for suzzi doesn't list the engine and only seems to say check for good compression, but this is a tiddly engine with a tiny capacity, I doubt I should expect 300lb type figures?

Cheers in advance.
 
DogWatch said:
Does anyone know a ballpark figure for a suzuki DF2.5. Or an exact figure. The workshop manual I have for suzzi doesn't list the engine and only seems to say check for good compression, but this is a tiddly engine with a tiny capacity, I doubt I should expect 300lb type figures?

Cheers in advance.
Click to expand...
Jools
If I dont get it right on pulling, my wrist knows about it!
Stu
PS very roughly, 10 to 1 compression ratio, 10 times atmospheric pressure of 15 psi ish equals 150 psi!
 
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Is that a two stroke?
If so, you are unlikely to measure the nominal compression ratio using the pull cord.
Also two strokes can have OK cylinder compression, but not start due to crank seals blowing.
 
lw395 said:
Is that a two stroke?
If so, you are unlikely to measure the nominal compression ratio using the pull cord.
Also two strokes can have OK cylinder compression, but not start due to crank seals blowing.
Click to expand...

The clue is in the model designation. DT for two stroke DF for four stroke.
 
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Thank you all, I reckon from all the figures given the ball park is around 160 psi.

The engine is 2007, so what, I should expect above 120 I think would be fair. Lakey, the compression tester I have (presume most do) holds the maximum, so if I give it half a dozen good pulls that should be telling me a fairly good result I would have thought. I haven't used the tester in years, who's betting it will be u/s. 300 was my honda prelude I think, but I may be miss remembering that, it was the first figure I plucked from the air.

The engine wont idle without me just nudging the choke on a bit, I have been through the obvious, but I have to say, it is behaving as though it has a leaky valve. I would like to rule it out. I was going to have a go today but it was too cold, being May 'n' all.

p.s. cheers Vic, I was looking for a figure in the workshop manual but lost the will to live, then again, that manual you posted would shake the patience of a saint, it's really slow to load and you can't leave any page until you zoom out. Looks a far better manual than the pdf version I have here though, Thank you for that.
 
More thinking while I type.

As lakey suggested figures may be ropey on the rope pull, I wonder if my battery drill would get a nice constant speed up before giving off that acrid smell of burning bushes we all know so well!
 
DogWatch said:
More thinking while I type.
As lakey suggested figures may be ropey on the rope pull, I wonder if my battery drill would get a nice constant speed up before giving off that acrid smell of burning bushes we all know so well!
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Jools
Ive just done mine, the float bowl had some **** in BUT worst of all, the jets had a bit of verdigris in them, I poked and prodded them with some COPPER wire. It ticks over bootiful now
Stu
 
I have cleaned crud out of the bowl and blew air duster through the jets, but I am willing to try again if the sun is out. I don't like poking jets, I knackered a carby once being a bit vicious with the poking wire. It is worth a try though and while I have the very nice council supplied blue-bin-outboard-test-tank™ out I will bung the comp tester on to see what kind of squashy squashy I am getting. This will be around the 5th time I will strip down the carb, oh joy :cool:
 
DogWatch said:
I have cleaned crud out of the bowl and blew air duster through the jets, but I am willing to try again if the sun is out. I don't like poking jets, I knackered a carby once being a bit vicious with the poking wire. It is worth a try though and while I have the very nice council supplied blue-bin-outboard-test-tank™ out I will bung the comp tester on to see what kind of squashy squashy I am getting. This will be around the 5th time I will strip down the carb, oh joy :cool:
Click to expand...
Jools,
copper softer than brass, poke the air bleed passageways as well.
Trust me, mine is running fine now!
Stu
 
The manuals on that site can be real pain. Some seem to load reasonably well while others take forever .

Difficult to get a good reliable figure with a pull chord. More meaningful on larger engines with electric start.

Heavens knows how they would get a figure of 199 psi ...... spinning it with an electric drill perhaps.

I reckon you should get better than 137 if all is well but I have no feel for what to expect from a small 4 stroke outboard

( Dunno what you are remembering for 300.... maybe not in psi )

Symptoms you describe, namely needing a bit of choke to keep idling, would lead me to taking another look at the carb. But you already have!
 
I have the same engine and had the same symptom which could also be cured by using a little choke. As some other posters have indicated, it turned out to be a blocked jet.
 
If you can get use of an air line with about 150 psi available it really blows out the jets and passages. it's the volume of air as much as the pressure that does the job.. (use PPE)
 
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Doggy me awld Mate
I would lean to the jet poking others have poked at
The fact that you can overcome the tickover prob by firtlin with the choke tells me this
Lack of combustion chamber compression would give a different symptom
Crankase compression, or lack of it would affect idling however and firtlin with the choke may 'help' if this is the prob
Sometimes because little outboards stand idle for a while.
The crank seals can go 'hard' and do not seal correctly
If the timing side seal aint sealing lack of crank pressure can arrive
9 times out of 10 tis the pilot air passage or jet that causes your symptom.
 
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