My honda odyssey has around 120 psi compression. I put my hand over the carb and it not sucking my hand in at all........ I don't have my pull start working so I'm just using a rope. Could the pull start not being on make it so it doesn't seal or something?
Honda odyssey no suction on carb
- Thread starter RandomK
- Start date
for all I know the FL250 NEVER was able to draw your hand through the carb.
simple reason it's a two stroke engine!
the engine inhales into the crank case which is quite a bit bigger than the combustion chamber,
the crank case is ported to the combustion chamber which in turn is open to the exhaust..
No way you can feel a lot of pressure difference on the carb side.
especially not at slow rotational speeds.
'sid
simple reason it's a two stroke engine!
the engine inhales into the crank case which is quite a bit bigger than the combustion chamber,
the crank case is ported to the combustion chamber which in turn is open to the exhaust..
No way you can feel a lot of pressure difference on the carb side.
especially not at slow rotational speeds.
'sid
Wowww
I've only worked on 4 stokes. I took the engine off and apart looking for an issue and couldn't find any.... But the good thing i found is some scoring on the piston and walls. But still has 120psi.. do I need to do something about it, it feels smooth. Also the piston move side to side a good amount....not the rod just the piston
But also how does the fuel pump thing work? Wouldn't it need to have suction to bring it to the carb ?
I've only worked on 4 stokes. I took the engine off and apart looking for an issue and couldn't find any.... But the good thing i found is some scoring on the piston and walls. But still has 120psi.. do I need to do something about it, it feels smooth. Also the piston move side to side a good amount....not the rod just the pistonBut also how does the fuel pump thing work? Wouldn't it need to have suction to bring it to the carb ?
Kent
Member
I guess we must assume your engine is not running or is running poorly. Pull starting with a rope should not make any difference as long as your getting the engine to turn over fast enough to start. If the engine is not running do the basic checks for air, fuel and spark where appropriate. I don't know much about 2 strokes either but we all know they need those basics to run. If you find the engine has the basic needs then you may need to look into deeper issues like timing etc.
Maybe you can post some history on your engine and members here will be able to help you out. You will get it....Good luck.
Maybe you can post some history on your engine and members here will be able to help you out. You will get it....Good luck.
I have good spark, I've got it to start a couple of time but pouring some gas down the spark plug. It has a brand new carb and I was using a gravity feed tank to eliminate fuel pump problem. I think I got it to run one time from the carb but it started and revved up crazy high so I killed it. Its and 83 so it has a cdi.
running the engine on pure fuel ruins the internals!
a 20:1 fuel to (TWO STROKE!) oil is recommended IIRC.
[edit] just checked.. 20:1 is correct according to the honda fl250 workshop manual[/edit]
Now.. the fuel pump is a pulse pump, it doesn't need any suctions as you'd expect it only needs a difference in pressure at a regular interval.
that difference can be rather tiny and is surely provided by the engine.. especially when running.
the pressure difference will increase with a running engine compared to a manually cranked over engine,
simply because the resonance int he exhaust is helping you with that.
'sid
a 20:1 fuel to (TWO STROKE!) oil is recommended IIRC.
[edit] just checked.. 20:1 is correct according to the honda fl250 workshop manual[/edit]
Now.. the fuel pump is a pulse pump, it doesn't need any suctions as you'd expect it only needs a difference in pressure at a regular interval.
that difference can be rather tiny and is surely provided by the engine.. especially when running.
the pressure difference will increase with a running engine compared to a manually cranked over engine,
simply because the resonance int he exhaust is helping you with that.
'sid
people claim a lot of things
BEST can mean different things as well..
truth is: HONDA says 20:1
and what they have in mind is reliability and performance
And although the manual is from the early eighties (I think 1981/82) it's something I would follow for now.
two stroke oils improved over the years and the ratio at whcih they're mixed dropped because of that,
but I would NOT trust some unknown random guy stating 32:1 is best at all
not knowing what oil he used and what fuel he had,
it's not impossible that his engine with a 32:1 ratio lasts for 10k miles from one rebuild to the next,
wheras yours with a 20:1 ratio (using the same grade fuel and identical oil) lasts 20k miles under similar conditions.
Truth is.. with more fuel the engine will perform better, a bit more power and a snappier reaction.
But it's NOT a race kart at all
(race karts fuel up with a 40:1 or even 52:1 fuel to oil ratio at times... but they will need full maintenance every couple of racing hours)
If you find race grade two stoke oil it's save to get a hint more fuel in than what the 40 year old manaul states, I bet.
But 50% ??? IDK I wouldn't trust that unless Honda says so.
22:1 25:1 sure ... maybe.. why not..
but 32:1 is quite a big step from the suggested 20:1..
'sid
BEST can mean different things as well..
truth is: HONDA says 20:1
and what they have in mind is reliability and performance
And although the manual is from the early eighties (I think 1981/82) it's something I would follow for now.
two stroke oils improved over the years and the ratio at whcih they're mixed dropped because of that,
but I would NOT trust some unknown random guy stating 32:1 is best at all
not knowing what oil he used and what fuel he had,
it's not impossible that his engine with a 32:1 ratio lasts for 10k miles from one rebuild to the next,
wheras yours with a 20:1 ratio (using the same grade fuel and identical oil) lasts 20k miles under similar conditions.
Truth is.. with more fuel the engine will perform better, a bit more power and a snappier reaction.
But it's NOT a race kart at all
(race karts fuel up with a 40:1 or even 52:1 fuel to oil ratio at times... but they will need full maintenance every couple of racing hours)
If you find race grade two stoke oil it's save to get a hint more fuel in than what the 40 year old manaul states, I bet.
But 50% ??? IDK I wouldn't trust that unless Honda says so.
22:1 25:1 sure ... maybe.. why not..
but 32:1 is quite a big step from the suggested 20:1..
'sid
Mr_mcrib212
Inmate #2148
Lol unknown random guy is literally everyone on this forum
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So I got it kinda running. It will only start with some fuel pored does spark plug. Then it will start and revs crazy high and I turn off and on kill switch to keep it running. So it is running from fuel it the carb if I don't turn off and on kill switch it just revs higher and higher
depends on whom you listen to
But yeah.. claiming it's in the Honda manual without proof sounds random guy'ish
So here's the first page of the manual:
and here's the spec_page (with the fuel ratio )
20:1 in the 1981 Honda shop manual.
'sid
Karttekk
Well-known member
It almost sounds like you have a crankcase leak when you say it revs higher and higher. You're possibly sucking air in through the crankshaft seals or another area and it's running lean. 2 cycle engines need to be completely sealed to run properly.
Troubleshooting Air Leaks
These information explains how to detect and repair an air leak on a pro saw.
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