Tecumseh 5hp cant get started !!!

[mrbeggs432]

Decided to start my own thread vs tagging on someone else that had the same problem.

Anyway... I have this Tecumseh 5hp engine that I cant get started. I believe is was off a tiller.

Seemed to be in pretty good shape....I tried to get info off another thread and tried everything they suggested.

It has gas & oil
Cleaned carb,jets,bowl jet - valve ?
I have a good plug and tried an additional good plug.
Got spark with both.
tried spraying carb cleaner in to try that - no fire
checked kill switch groundwire - tried connected & disconnected
Flywheel key is NOT sheared
coil unit & flywheel gap...I can shove a piece of paper through.

I really dont want to give up on this motor due to Im building a freebie for my friends grandkids.

Any other idea's beside's a stick a dynamite ????

 

[BeaterofAincrad]

Is the spark plug wet after trying to start it?
Have you tried turning it over without the plug on it to get rid of anything that’s in there?

 

[Xtreme Yard Karts]

Pull the valve cover and first make sure both rockers are moving, and the check valve lash. The valve lash should .003" - .005" with no lift on the cam (turn the engine over until the cam on the base circle).
These engines are known to drop valves if the governor has been removed and the valves have been allowed to float.

Once you get it running, do yourself a favor and buy a carb for a HS40 off eBay or Amazon for about $15. They have an adjustable idle jet and main jet on the bottom of the carb, and they run much better than the fixed jet carbs the OHH engines come with.

The OHH engines are very good engines that are plagued by a terrible carb design.

 

[Skape]

Hey I have the same issue, mines was fine then last weekend it wouldn’t start, I sprayed some starting fluid and it started but my throttle was stuck on full throttle and it leaked oil from the carb. Then it started to smoke real bad white smoke. I never had an issue before and now I’m stuck. I dnt knw what to do?

 

[Nosandwich]

Hey I have the same issue, mines was fine then last weekend it wouldn’t start, I sprayed some starting fluid and it started but my throttle was stuck on full throttle and it leaked oil from the carb. Then it started to smoke real bad white smoke. I never had an issue before and now I’m stuck. I dnt knw what to do?

Read your own thread and quit hijacking.

 

[mrbeggs432]

Say what ???

Pull the valve cover and first make sure both rockers are moving, and the check valve lash. The valve lash should .003" - .005" with no lift on the cam (turn the engine over until the cam on the base circle).
These engines are known to drop valves if the governor has been removed and the valves have been allowed to float.

Once you get it running, do yourself a favor and buy a carb for a HS40 off eBay or Amazon for about $15. They have an adjustable idle jet and main jet on the bottom of the carb, and they run much better than the fixed jet carbs the OHH engines come with.

The OHH engines are very good engines that are plagued by a terrible carb design.

Please excuse my ignorance......cam on the base circle ??? Do you mean when the lifter comes up and pushes on the rocker to its fullist ? or when it goes all the way down and no pressure on the rocker arm ? Im more of a fabricator then a mechanic....but, I just bought a shiny new feeler gauge from Harbor Freight !

---------- Post added at 04:55 PM ---------- Previous post was at 04:03 PM ----------

Please excuse my ignorance......cam on the base circle ??? Do you mean when the lifter comes up and pushes on the rocker to its fullist ? or when it goes all the way down and no pressure on the rocker arm ? Im more of a fabricator then a mechanic....but, I just bought a shiny new feeler gauge from Harbor Freight !

Not sure if I was doin it right....watched a youtube video on a overhead cam Briggs.
It showed rotating the motor until one valve spring bottomed out and then measure the opposite one's clearance...I came up with 0.15 on the exhaust side & .030 on the other....is this being done right ?

 

[BeaterofAincrad]

I’ve only done it on mower, but yeah it sounds about right. That’s WAY to much of a gap though.

EDIT:
Here’s the vid I used for the mower, skip to 3:50

https://m.youtube.com/watch?v=0cWoEk5Guos

 

[Xtreme Yard Karts]

Please excuse my ignorance......cam on the base circle ??? Do you mean when the lifter comes up and pushes on the rocker to its fullist ? or when it goes all the way down and no pressure on the rocker arm ? Im more of a fabricator then a mechanic....but, I just bought a shiny new feeler gauge from Harbor Freight !

---------- Post added at 04:55 PM ---------- Previous post was at 04:03 PM ----------



Not sure if I was doin it right....watched a youtube video on a overhead cam Briggs.
It showed rotating the motor until one valve spring bottomed out and then measure the opposite one's clearance...I came up with 0.15 on the exhaust side & .030 on the other....is this being done right ?

I mean with no pressure on the on rocker. If you have any lift at all, the measurement is no good.

If you had .015" and .030", that's way too much. It should be .004" +/- .001". That would be .10 - .15mm if you happened to get a metric feeler gauge.

 

[mrbeggs432]

I mean with no pressure on the on rocker. If you have any lift at all, the measurement is no good.

If you had .015" and .030", that's way too much. It should be .004" +/- .001". That would be .10 - .15mm if you happened to get a metric feeler gauge.

Okay....so I set them at .004 still have spark....wouldn't fire up and tried spraying carb cleaner inside...still won't fire...could weak spark be an issue ??? Or spark is spark.....reason I ask I had weak spark on my Polaris 4x4 and it wouldn't start....I changed to new solenoid and it had stronger spark....and fired up

 

[TT540]

Carb cleaner is not Starting Fluid. Carb cleaner actually bogs and stalls a running motor.

Starting fluid (aerosol can) is your friend when you work on small engines. It is tricky to spray into that particular carb/elbow setup. So having a friend to squirt while you pull is a plus.

Quotable.

 

[BeaterofAincrad]

I’d try a new plug. I just recently worked on a dr.powerwagon wheel barrow and I cleaned the carb and it still would not start, it wouldn’t even turn over with carb/choke cleaner either. I had good spark, but decided to get a new plug due to there being some carbon on it and it fired right up first pull.

EDIT:
If there was oil coming out if the carb then that means it was also in the cylinder. So it had to have affected the plug in some way.

 

[mrbeggs432]

Pull the valve cover and first make sure both rockers are moving, and the check valve lash. The valve lash should .003" - .005" with no lift on the cam (turn the engine over until the cam on the base circle).
These engines are known to drop valves if the governor has been removed and the valves have been allowed to float.

Once you get it running, do yourself a favor and buy a carb for a HS40 off eBay or Amazon for about $15. They have an adjustable idle jet and main jet on the bottom of the carb, and they run much better than the fixed jet carbs the OHH engines come with.

The OHH engines are very good engines that are plagued by a terrible carb design.

Got that carb you suggested....dam thing stil wont fire..IDK getting pretty irritated....is there such thing as as spark too weak ???

gonna get some starter fluid in the morning....Its either gonna fire .......or blow up !!!

 

[jim454]

Are you sure the carb is getting clean fuel.If my 8hp sits for too long I have to blow out the fuel lines and carb.If you have good spark it has to be fuel related.

 

[bob58o]

Spark
Air
Fuel
Timing
Compression

That is all you need. You claim to have the first 4, then you can't have compression. Air, Fuel, Compression, and Spark at around the correct time and the engine will at least try to run.

Take the plug out, Hold your thumb over the spark plug hole. Pull the starter cord. Do you feel much pressure on your thumb?

I suppose the spark could be too weak. The flywheel magnet or ignition coil might be bad.??

Who said Carb cleaner won't start an engine? GTFOH! LOL

---------- Post added at 10:59 PM ---------- Previous post was at 10:53 PM ----------

Carb cleaner is not Starting Fluid. Carb cleaner actually bogs and stalls a running motor.

:toetap05:

 

[BeaterofAincrad]

I remember watching a vid where it said if you have a nice blue spark, your spark is good, and if you have a yellowish spark then you may want to get a new plug.


I was thinking the same thing bob. I was also told it’s not the best for your cylinder if you directly spray it constantly into the spark plug hole because it ends up drying the oil on the cylinder wall. You know, doing it’s job LOL

 

[bob58o]

Acetone
Xylene
Toluene
Methyl Ethyl Ketone
2-Butoxyethanol
Propane


There are probably some things in carb cleaner that wont burn. I just can't find any. LOL

---------- Post added at 11:14 PM ---------- Previous post was at 11:08 PM ----------

Carb cleaner is not Starting Fluid. Carb cleaner actually bogs and stalls a running motor.

Quotable.

Well if your A/F ratio is correct when running and you spray extra fuel into the mix, your A/F is not correct anymore.

 

[Nosandwich]

What he said ^^^^

 

[KartFab]

Follow this exactly:
set your coil gap,
make sure that the flywheel and coil are not rubbing.
take the ground wire off of the magneto,
take the carb off the intake.
spray a 1/2-1 second of carb cleaner, starting fluid, whatever into the engine.
pull start it at least 3-4 times, shoudl fire up and run for a second or two and die. If it revs too fast, you can just put your hand over the intake to kill the engine

If you truly have spark, air, fuel, and timing. you can 'sort of' test compression by rotating the flywheel with your hand just rotate it hard and it will hit a spot where it just bounces back and rotates the opposite direction because of the compression.

Im thinking you are grounding your magneto somehwere you didnt think of, remember there are like 3 or so wires that plug into the shroud and kill switch. you can just unplug them all so NOTHING is connected to the magneto, except for the wire that goes to the spark plug.

 

[mrbeggs432]

Follow this exactly:
set your coil gap,
make sure that the flywheel and coil are not rubbing.
take the ground wire off of the magneto,
take the carb off the intake.
spray a 1/2-1 second of carb cleaner, starting fluid, whatever into the engine.
pull start it at least 3-4 times, shoudl fire up and run for a second or two and die. If it revs too fast, you can just put your hand over the intake to kill the engine

If you truly have spark, air, fuel, and timing. you can 'sort of' test compression by rotating the flywheel with your hand just rotate it hard and it will hit a spot where it just bounces back and rotates the opposite direction because of the compression.




Im thinking you are grounding your magneto somehwere you didnt think of, remember there are like 3 or so wires that plug into the shroud and kill switch. you can just unplug them all so NOTHING is connected to the magneto, except for the wire that goes to the spark plug.

OK.....

removed coil and cleaned contacts reset with clearance of about a sheet a paper.

Only one ground wire to magneto kill switch -removed...no oil alert or other wires.

checked 2 new plugs gapped at .030

still have spark

Put thumb over plug hole and pulled....feel some compression.

Ok...now I tried spinning flywheel by hand with sparkplug in......NO kickback at all....I can just spin flywheel with little resistance...

Is it time to go to Harbor freight ???????

 

[Xtreme Yard Karts]

Those engines have a built de-compression relief in the cam, so they spin over easy. Did you ever try starting fluid or gas in the carb instead of carb cleaner.
Despite what's in it, I've seen a lot of carb cleaner that will not start an engine.