5hp 130200 starts when gas poured into carb but will not run - carb looks clean

This B&S 5 hp model 130200 engine is on a Roto-Hoe Cut'N Shred Shredder, Model 500. It has been sitting idle for more than 10 years. After trying to start engine with no luck, even with dribling gas down the carb, I did compression test. Could only get 30 lbs. Popped the head off and found that the intake valve did not seat tight until piston was almost to the top of compression stroke. I ground down the end of the valve stem until the valve seated tight at the beginning of the compression upstroke. Reassembled. I now got 60 lbs compression, which is what it should read because of the compression relief gizmo, of which I know nothing, just that it was mentioned in a couple of YouTube videos by guys with thick country accents, so you know they know there small engines.

So anyway, the engine coughs to life and sounds strong for about 3 to 5 secounds when I dribble gas down the carb and pull the starter 3 or 11 times (it varies), but it will not run. I figure it has to be a fuel delivery problem, but as I mentioned earlier, the carb looks very clean.

Do any of you helpful people have any suggestions? The gas tank was clean and bone dry and I put in fresh gas. The oil level is good.

Jack
Fresno, CA

:welcome:

Nothing like brute force & ignorance to made simple things complicated :laughing:
When turning the engine over by hand the inlet valve SHOULD STAY OPEN till just before TDC compression stroke.
Or close then reopen just a few thou just before TDC
The decompression on these engines is in the grind of the cam.
You should see around .004" valve lash on both valves 1/4" past TDC compression stroke.
That is how you set valve lash not by weather the valve is opening at what you think is the right or wrong time.
So now you will need to either grind down the valve seat or replace the valve to reset the correct valve lash.

Once you are back at a valve lash of .004" you will be back to the start.
Usually it is the exhaust valve that sticks open and that is due to rust on the stem or on the seat.

Low compression on engines that have not been used for a long time is either a valve hanging or the rings rusted into the piston.

Hillbilly test is to cut a hole in a cork that will fit into the spark plug hole to take an air duster.
Set the engine to TDC compression stroke then remove the dip stick and blow down the plug hole
Check the carb muffler & dip stick tube for air escaping.
You should get a little gentle blow from the dip stick.

Educated hillbilly method is to use an old tyre valve hooked up to a tyre inflator with a pressure gauge in place of the air duster.
The cylinder should hold around 100psi with a gentle leak out of the dipstick tube.

If no joy, heat the piston with an air gun down the plug hole.
Get the engine good & hot then pour some oil down the plug hole, put an old plug in there and crank the hell out of the engine.
This process might need to be repeated a couple of times.

For future refference we need the entire engine number 130200-????-?? so we can look up the parts book.
When you have an engine that you are not familiar with, look up the parts breakdown for the cam.
Have a good look at it , if there is no counterweight depicted on it then the ACR is part of the cam grind or not there.

bertsmobile1 said:

:welcome:

Nothing like brute force & ignorance to made simple things complicated :laughing:

Click to expand...

Not the first time, won't be the last, I'm sure I will take the appropriate action to correct valve lash. I would never have done that without prompting from the internet: "Repairing intake vavle leak, briggs and stratton flathead" https://www.youtube.com/watch?v=E3y9gnqigJA

The complete number is 130202-4003 01. I used 130200 because that is on the PDF that B&S website had for complete model number I entered.

I thank you for sharing your knowledge. Sometimes, with me, the hard way is the only way. I wish it weren't so.

Jack

Jack.
You have the most important tool any tool box can have,,,,
A sense of humour and the ability to see humour in the failings of others & yourself.

As for You Tube.

The bulk of what is there is more about the ego of the presenter than their willingness to share real knowledge.
If you find accents hard then I can recommend Donnyboy73 being a Canadian he has a fairly flat accent speaks slowly & always shows part numbers.
Some of the stuff up there is almost criminal and most is rubbish.
Taryl Fixes All is quite good if you skip past the high school humour skit at the front.
In order to be paid for a visit the viewer has to stay there for 15 seconds which is why most have a long fancy animation at the beginning so at least Tary does not insult our intelligence by starting with an animation of his name all over the screen.
Absolute compression numbers are meaningless as they will vary depending upon the valve lash.
leak downs are the way to go on these engines
But with a fails to start situation your ear will do just fine.
Get a copy of the Briggs L head repair manual.
There are a few sites with them on line and others much better than me at surfing seem to be able to find them & post links a lot faster than me going back through my diary to see where I got it from.
Also when you do the lash, note there are 2 sets of numbers.
One for the valves installed and another for the valve loose in the head.
If you do the latter, go for the big end as it tends to be a lot tighter with the springs on.

Briggs can be a PIA for parts books.
While the book is the same for all 130200 regardless of the code but you need the code to get the book that does not need the code.

Good that you mentioned leakdown test. It reminded me that I have a leakdown tester from when I had a blown head gasket on my 87 Dakota.

The thing that I can't shake is that I only got 30 lbs on compression test, and no start when dribbling gas into carb, before grinding valve, and after grinding valve I got 60 lbs of compression and engine started when dribbling gas down carb. It just won't continue to run. This screams "fuel delivery problem". EBay is selling these carbs new for under $20 delivered. The valve lash may not be correct, but the engine starts. It just doesn't run on its own fuel delivery system. It starts and runs until the fuel I dribble down the carb is used up, about 3-5 seconds. If I can't get it to run on its own tomorrow I just may order a new carb.

berts, speaking of carbs, there is a long tube on this one used to pull fuel up from tank, and a shorter aluminum tube with a jet on the end that goes into a well at the top of the gas tank. Do you know what is the purpose of this shorter aluminum tube with jet on end? Is it an air bleed?

The long tube is as you worked out the pump
The short tube is the main jet holder.

This carb uses a cup in the fuel tank as the float bowl but being in the tank, it just overflows back into the tank
Take the screen off & clean it
Then clean the main jet
While you are there replace the fuel pump & diaphragm.
The diaphragm goes hard with time & does not pump particularly well.
If the fuel well in the fuel tank is not full then the engine will do exactly what yours was doing.,,, not start & only run through the fuel you pour down the carb throat.

As for cheap Chinese Carbs
Run a mile from them
There is no such thing as a scrap part in China.
So the ones that fail the Briggs quality control get on sold to disposal companies then to cheapskates via ebay.
The beast test is to check the "other items" that the seller is flogging.
If they are all mower / motorcycle etc related then better than average chance they will be good.
OTOH if they sell everything from candles to condoms then there is a better than average chance they are defective rejects
Empty the fuel reseviour in the tank.
Put the carb back on and crank the engine, plug out for a minute.
Remove tank and check the reseviour
It should be almost full , remember the main jet holder sits in there & so the level will be a little lower than the overflow.
OR stick a mirror in the 1/2 full tank and crank the engine looking for overflow from that reseviour.

To clean the pick up tube I use a syringe to backwash from the pump.
On some the pick up tube can be unscrewed, others pull out but in my case most break & if they don't then they fall out when put back.

Count the number of bolt holes for the diaphragm & gasket as there are few different variations & only the correct one will fit.
Usually I use the Rotary kit from my wholesaler which comes with a diaphragm, gasket, spring & spring collar about $ 10 in monopoly money.

jack6128 said:

berts, speaking of carbs, there is a long tube on this one used to pull fuel up from tank, and a shorter aluminum tube with a jet on the end that goes into a well at the top of the gas tank. Do you know what is the purpose of this shorter aluminum tube with jet on end? Is it an air bleed?

Click to expand...

As bert mentions about the little well. The actual purpose behind it is the vacuum that is reacted when air rushes through the carb venturi can only cause an 1.5 inch lift in the fuel. So you have to pump the fuel from the bottom of the tank and then create a small internal tank for the engine to draw fuel from. If you are not getting fuel into that little well it will not run So either the jet on the end of the short tube is clogged, the small well has rusted through and is leaking fuel back into the main tank, or the fuel pump diaphragm isn't pumping fuel up into the well. Could be cause by lack of intake pulse, or maybe the diaphragm is worn out, or possibly the spring and cap behind it are not installed correctly.

Thank you both, bert and ILENGINE. Your help is greatly appreciated. I seemed to think that the well might be for fuel, but wasn't certain. Thank you both for pointing this out. I will pull carb and see if it is filled, and if not, fill it, clean filter, make sure jet is unobstructed, reassemble and see if pump works to draw fuel from bottom of tank. I will pull tank again and check valve lash while I am at it.

It looks like I was on the right track in grinding down the intake valve. Following B&S instructions on "How to Adjust Tappet Clearances" I put the piston 1/4" down from TDC of compression stroke and I cannot fit even the smallest feeler gauge, .002", between the pushrod and the valve stem of either valve. B&S calls for between .005" and .007" for intake valve, and between .009" and .011" for exhaust valve. Exhaust valve is looser as I can spin it, and the intake valve is tight, cannot spin it. This tells me the exhaust valve needs more grinding than the intake valve. I'm fairly sure I am reading this correctly, so it is grinding time again.