# Should Have Left Good Enough Alone



## Smolenski7 (Nov 24, 2010)

I recently purchased a 30 year old single stage Bolens 320. It's powered by a Briggs 62030 2-cycle engine that has a diaphragm style carburetor.

After a little work it was running fine, although it would surge just a bit. A few days ago I put about 1.5oz of Seafoam in the cylinder to give it a good cleaning, I can see the carbon build up on the piston behind the plug easily. I let it sit until yesterday and started her right up. It smoked like crazy, but ran fine. It was certainly still surging a bit, but I expected that.

I then attempted to adjust the needle valve. I adjusted it several times, both clockwise and counter-clockwise. Nothing seemed to make a difference. After the last adjustment, I couldn't get the engine started again. 

I let it sit over night, but that did nothing. I even changed the spark plug, but still nothing. I opened the carburetor, but it looked clean. There is not reason why it wouldn't be clean. There is definitely fuel coming from the tank to the carburetor, there is no blockage. The only way I can get it to turn over for just a few seconds is to either add Seafoam to the cylinder or add starting fluid to the carburetor. 

Just to note, the primer is definitely showing some age. It is cracked and fuel does come flying out after a few pumps. This is nothing new, it has happened since the day I bought it a few weeks ago.

I have no idea what to do next. 

Any ideas?

Here's a link to the engine.

Briggs and Stratton 62030 Series Parts List and Diagram : eReplacementParts.com​


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## AL- (Oct 27, 2014)

The seafoam and starter fluid seem to be giving better combustion in the short term. Maybe instead of seafoam put a little bit of motor oil in the sparkplug hole to see if it would run as this might give better compression. What fuel mix are you using a 50:1 maybe?


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## Smolenski7 (Nov 24, 2010)

AL- said:


> The seafoam and starter fluid seem to be giving better combustion in the short term. Maybe instead of seafoam put a little bit of motor oil in the sparkplug hole to see if it would run as this might give better compression. What fuel mix are you using a 50:1 maybe?


Manual says to run 30:1, so that's what I have been using.


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## guilateen02 (Nov 23, 2014)

My guess is the seafoam broke loose some gunk and is now stuck in a passage way. Even though it looks like you just cleaned it one speck could clog the carb.


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## skutflut (Oct 16, 2015)

guilateen02 said:


> My guess is the seafoam broke loose some gunk and is now stuck in a passage way. Even though it looks like you just cleaned it one speck could clog the carb.


I agree. If the last thing you were doing involved the needle valve, I would go back to that. Did you mark the original position so you could return to it? Did you by any chance close it all the way at any point? Is the tip or seat damaged?


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## Kiss4aFrog (Nov 3, 2013)

:iagree: I'm with them.


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## Grunt (Nov 11, 2013)

Is the spark plug wet after trying to start it multiple times? Two strokes store excess fuel in the crankcase and you may have to remove the spark plug and pull the recoil until your arm is tired to purge the excess fuel.

Have you tried putting a little fuel mix into the cylinder and try starting it, to prove it is a carb issue?

Have you confirmed you still have spark when trying to start it?


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## Smolenski7 (Nov 24, 2010)

Great. Lots of suggestions.

I don't think the needle valve has any problems. I did pull it out and inspect it. I'm not expert, but it looked fine.


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## skutflut (Oct 16, 2015)

Smolenski7 said:


> Great. Lots of suggestions.
> 
> I don't think the needle valve has any problems. I did pull it out and inspect it. I'm not expert, but it looked fine.


Still looking for a blockage. Since it fires when youninject fuel, you know o have spark, I assume you have good fuel and air, but the fuel isn't getting past the card is what it sounds like.


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## Sid (Jan 31, 2014)

While the needle looks fine, the little passageways that go toward, and away from the needle may be clogged. It may need a good soaking, and a blowout.
Sis


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## bad69cat (Nov 30, 2015)

I bet the diaphram broke or the seafoam ate it up...... crack open the carb and look at it. One that old was likely to let go anyway. Parts list here: https://www.m-and-d.com/pdfs/briggs/62030-ms7560-0886.pdf


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## Smolenski7 (Nov 24, 2010)

Nurse, check the time. All hope might be lost.

I cleaned the carburetor....again. Nothing.

I checked the fuel lines....clean and good flow. Nothing.

I check for spark....well it sort-of turned over once when there was some left over fuel in the carburetor so there must be spark. Nothing

Finally, I pour about .5 oz. - .75 oz. of oil behind the plug. Siezed! Almost impossible to pull the cord.

I think I need to call it. Too bad, it was running fine (besides a little surging) just a few days ago.


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## nwcove (Mar 2, 2015)

i dont think it seized, probably just hydrolocked from the oil on top of the cyl. take the plug wire off and turn the engine over backwards from the direction the recoil would spin it, the oil should run out through the exhaust port .


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## bad69cat (Nov 30, 2015)

Agreed...... 2 stroke will hydrolock easy


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## AL- (Oct 27, 2014)

Smolenski7 said:


> Nurse, check the time. All hope might be lost.
> 
> I cleaned the carburetor....again. Nothing.
> 
> ...


In my little 4hp - 4cycle with diaphragm, after sitting around for a long while I pulled on the cord and there seemed to be no compression so I put a little oil in the plug hole, put the plug back in and could not pull the cord, so I took the plug out and could easily pull the cord a few times, so I put the plug back in and pulled the cord and it turned over and the compression seemed normal. I just thought it had lost compression because there was not enough of an oil coating in rings and cylinder.


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## nt40lanman (Dec 31, 2012)

I say keep at it until you figure it out even if only for the education


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## Smolenski7 (Nov 24, 2010)

nt40lanman said:


> I say keep at it until you figure it out even if only for the education



Agreed. Kinda why I bought it.


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## Smolenski7 (Nov 24, 2010)

Ok, so I just came in from the garage. Turns out it was just hydro-locked. I took out th plug, pulled the cord a few times and a bit of oil came sprewing out. I replaced the cord and I was able to pull the cord again.

However, I still think it is starved for gas. I can pull the cord 8-12 times and it will start for a few seconds. A ton of white smoke will come out of the muffler, I assume that is the oil burning off. However, once the smoke goes away, after a few seconds, the engine cuts out and I have to start pulling the cord again.

What could I have done? The only thing I did was adjust the needle valve. I pulled it out today when I was cleaning the carb. It appears to be fine. There is still a point and it is really clean.


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## ELaw (Feb 4, 2015)

Just a few random thoughts...

You say the primer "is cracked and fuel comes flying out"... do you mean fuel comes out of the primer, or the carburetor? If the primer leaks fuel, it's probably leaking air too... which may make the carb unable to draw fuel from the tank.

The next thing I'd try is (carefully) pulling the bottom of the carb off. The trick is you don't want to damage the diaphragm. Before you do that, examine the parts diagram until you understand how that part of the carb goes together, because when you remove the diaphragm some small parts are likely to come flying out and you need to know where to put them when you reassemble it.

With the diaphragm off, examine it carefully for any cracks... even a tiny one can make the carb not work right. Then check everything around it... it's possible a speck of dirt or something got in there and is making things not work right.

For what it's worth, if you put Seafoam in the spark plug hole and not in the gas, I don't buy that it damaged the carb. To get to the vulnerable part of the carburetor (the diaphragm), it would have to travel backwards all the way through the engine, through the intake port (which could happen only if the piston was not covering it) into the carb, then backwards through the jets to the diaphragm. That's highly unlikely... I think the problem you're having is just coincidental.


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## Kiss4aFrog (Nov 3, 2013)

I'm guessing since it's a 2 cycle it's the actual primer bulb that might be cracked since it actually is pumping gas.
If you can't get a P/N for it you might get lucky with a "variety pack" containing a few sizes, hardware store, big box, ...

I don't know enough about 2 cycles but it's possible with that thing cracked the carb is sucking air instead of being able to pull gas from the tank.

Arnold Primer Bulb Variety Pack for Handheld Equipment-490-239-0001 - The Home Depot


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## wdb (Dec 15, 2013)

I'm tossing in with the folks who say something popped loose when you tweaked the needle valve. Tiny little orifice somewhere is blocked and gas is not getting through the carburetor to the intake manifold.


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## AL- (Oct 27, 2014)

My experience with my 2 cycle lawn boy this summer was that it would run okay then it would smoke and slow down. It has exhaust ports that can carbon up quite easily so when I took the muffler cover off ( had a hole in it) the muffler was full of grass clipping that would burn and then mower would run Ok then more clipping would get in and it would burn these and smoke and slow down, the ports however were clean and not the cause of the smoking. 
When I changed the diaphram on my 4hp -cycle the new diaphram was quite flexible and thin as compared to the old one


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## Smolenski7 (Nov 24, 2010)

I also noticed, the last time it ran, that if I let the choke out the surging stopped and the machine seemed to run very smoothly. Could this be connected to the primer being cracked?


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## skutflut (Oct 16, 2015)

Smolenski7 said:


> I also noticed, the last time it ran, that if I let the choke out the surging stopped and the machine seemed to run very smoothly. Could this be connected to the primer being cracked?


If you are sucking air in through the primer bulb, maybe its running lean, and adding choke compensates for the extra air getting in thru the primer


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## bad69cat (Nov 30, 2015)

Agree - she's sucking air and or a slight blockage in the jet still.


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## AL- (Oct 27, 2014)

Is there a way to use the primer then next quickly put a small piece of ready cut duct tape or small piece of plastic with film of goop around the edges, stuck on quickly with finger to seal over the primer bulb temporarily from a air leak, then start it running to see if that's the problem. 
Saran wrap might be too thin depending on the size of the crack

Good luck and Merry Christmas!


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## Smolenski7 (Nov 24, 2010)

I finally had a chance to get out to the garage today and replace the primer bulb. I bought a variety pack labeled as for Briggs and Stratton engines. One of the bulbs in the pack sort-of fit, it just needed a little trim around the base. Once I did that, it fit perfectly.

However, after I primed the engine a few times the real problem appeared. Gas was leaking between the intake cover and the carburetor. I thought at first I forgot to replace a gasket, however, after looking at the schematic I found out there never was a gasket in the first place. So, I quickly made a DIY gasket out of some blue felt. It seems to work fine, however, if someone has a better idea for a DIY gasket, I would love to hear it.

After some fine tuning of the needle valve, it seems to be running pretty well. I haven't had the opportunity to try it out yet on a few inches of snow, but this is New England so it has to come at some point. Just waiting....and waiting....








This is the gasket I made. It's certainly not perfect, but it seems to seal the leak.








This is the new primer bulb.








Finally, here it is just waiting to be tested by my 13 year old son. He's really excited. :icon_smile_wink:


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## AL- (Oct 27, 2014)

Smolenski7 said:


> I finally had a chance to get out to the garage today and replace the primer bulb. I bought a variety pack labeled as for Briggs and Stratton engines. One of the bulbs in the pack sort-of fit, it just needed a little trim around the base. Once I did that, it fit perfectly.
> 
> However, after I primed the engine a few times the real problem appeared. Gas was leaking between the intake cover and the carburetor. I thought at first I forgot to replace a gasket, however, after looking at the schematic I found out there never was a gasket in the first place. So, I quickly made a DIY gasket out of some blue felt. It seems to work fine, however, if someone has a better idea for a DIY gasket, I would love to hear it.
> 
> ...


Your son has a good snow blower mechanic !


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## skutflut (Oct 16, 2015)

Smolenski7 said:


> I finally had a chance to get out to the garage today and replace the primer bulb. I bought a variety pack labeled as for Briggs and Stratton engines. One of the bulbs in the pack sort-of fit, it just needed a little trim around the base. Once I did that, it fit perfectly.
> 
> However, after I primed the engine a few times the real problem appeared. Gas was leaking between the intake cover and the carburetor. I thought at first I forgot to replace a gasket, however, after looking at the schematic I found out there never was a gasket in the first place. So, I quickly made a DIY gasket out of some blue felt. It seems to work fine, however, if someone has a better idea for a DIY gasket, I would love to hear it.
> 
> There is gasket goo available that can be used to make an instant gasket that will seal once cured. You can also get sheet gasket material and cut out what you need. That felt might not provide a really good seal over time. It may not compress enough to prevent air seepage, and I have no idea what contact with gas might do to it.


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