# Briggs & Stratton 7.5HP Intek I/C OHV - fuel everywhere!



## RichmondDan (Feb 8, 2011)

My Craftsman tiller is 7 years old, but probably doesn't have 30 hours of use. I moved it here to Richmond from Colorado 3 years ago and it's been sitting in the garage since.

I decided to try to sell it on Craigslist, but first I wanted to make sure it still ran. I removed the old gas, put fresh gasoline in, and it started on the first pull! It ran for about 3 minutes, got nicely warmed up, then the fun started.

The engine started sputtering, then died. When I tried to start it again, white smoke came from the exhaust. Then I couldn't pull the recoil starter...almost like it was frozen. I removed the air cleaner and there was an inch of gasoline below the filter, in front of the butterfly valve. I checked the oil...plenty of oil. I was able to pull the recoil starter, but with great difficulty. Then I noticed gasoline dripping from the exhaust!

I closed the valve at the bottom of the fuel tank so that no more fuel would go to the carburetor and put the control in the "stop" position so the spark plug wouldn't fire.

As I tried repeatedly to pull the rope starter, it began to get easier and easier, with gasoline continuing to drip from the exhaust. I soaked up all the gasoline from the carburetor air intake and was eventually able to get the engine to turn over easily by hand, with little or no more gas from the exhaust.

My assessment: after running normally, something ruptured (a diaphagm?), causing gasoline to pour into the carburetor and then get sucked into the cylinder, above the piston. Because of all the liquid above the piston, it became very hard to turn over. By shutting off the gas and continuing to turn over the engine, I managed to get the gasoline pumped out of the cylinder.

Now what? My guess is that I need to remove the carburetor, but what should I look for? I may also have gasoline in the oil sump, if it was able to leak past the rings, so do I need to drain the oil and refill as well?

I have no clue what caused this, but it may be that some rubber part disintegrated after sitting idle so long. Any suggestions will be gratefully accepted.

Regards,
Dan


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## geogrubb (Jul 28, 2006)

The carb probably has a varnish buildup from setting so long and would not let the float rise to shit off the fuel, it will probably be necessary to remove the carb and clean it, also change the oil as it is probably contaminated from the fuel overflow, it will smell like gas. Have a good one. Geo


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## RichmondDan (Feb 8, 2011)

Since no one else has posted, I'll take this as the consensus as where to start. 

Can anyone provide a link to step-by-step instructions for disassembling, cleaning, and reassembling a Briggs&Stratton carburetor? I don't want to get it apart and not know what is needed to reassemble it properly.

Thanks!

P.S. It's a 7.0 HP engine, not 7.5 as shown in the thread title. The model number is 121302-0216-E1.


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## 30yearTech (Sep 14, 2006)

RichmondDan said:


> Since no one else has posted, I'll take this as the consensus as where to start.
> 
> Can anyone provide a link to step-by-step instructions for disassembling, cleaning, and reassembling a Briggs&Stratton carburetor? I don't want to get it apart and not know what is needed to reassemble it properly.
> 
> ...


Yes, I agree with geo that the carburetor probably needs cleaning and most likely a new float needle and seat. There used to be service manuals available online, but all the links recently came down. So now I only know that service manuals are available for purchase from dealers. 

You can remove the air filter cover and base and have access to the carburetor. If you have a digital camera, you can take pictures as you go along, to aid in reassembly. Post your questions and members on here can help you with instructions on how to proceed.

Best of Luck....


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## RichmondDan (Feb 8, 2011)

Thanks for your response. It occurred to me after posting that note that I should probably search YouTube also. I've seen amateur video on there showing how to rebuild carburetors on Stihl and other brand chainsaws, so there may be something for B&S as well.

If I find anything, I'll come back here and let you know. Those videos can be a godsend, when you're heading out to do something you haven't done before...


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## dj722000 (Oct 29, 2008)

You have to watch what videos you watch on youtube, they may be entertaining but may be wrong. (Not totally wrong, just may not be the right way for you to do it)

Carbs are not that bad to disassemble, repair, clean and reassemble and make them work right.

If you get the kit through a local dealer, pick there brains and they should give you enough of an idea to get you going. Maybe even a copy of the service info for it. (If there nice enough)

If you get stuck on it, take a pic throw it up on here and ask away, theres enough qualified people on here to help you.


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## RichmondDan (Feb 8, 2011)

Here are links to a guy that has done many small engine "how-to" videos. The first link is for one type of B&S carburetor, the second link is a catalog of his various other videos.






http://www.youtube.com/user/donyboy73#g/search


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## dj722000 (Oct 29, 2008)

This will work for you if its the same style carb. But yes, you should be able to figure them out even if its not.

He shows in the video that if its dumping fuel, he shows to replace the fuel needle seat. Also dont forget that it might be a bad float. If there is a hole in the float, well, it cant float to close off the fuel supply and will also dump gas all over.

But yeah, thats a good video.


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## RichmondDan (Feb 8, 2011)

I've watched several different carb videos now, so I'm feeling somewhat confident that I have some idea what I'll find when I open it up. I also have the exploded diagram in the owner's manual, which helps.

Thanks again, folks.


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## usmcgrunt (Sep 16, 2007)

You can view the teardown procedure for your carb here.Hope this helps.

http://outdoorpowerinfo.com/repairs/


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## 30yearTech (Sep 14, 2006)

The carburetor in the video will be very similar to the one on your tiller, and for the purpose of repairing your "flooding" issue should be fine to follow. I don't believe the carburetor on your engine will have the low speed adjustment screw as newer carburetors no longer have them. Also the newer carburetors have the main jet in the bowl nut and it's no longer on the side of the nozzle assembly. 

When installing the new needle seat in the carburetor be sure the side with the ridge goes down and does not face up or you may continue to have issues with flooding. Also make sure the atmospheric vent into the float bowl is not plugged or you may continue to have problems with fuel leaking out.




usmcgrunt said:


> You can view the teardown procedure for your carb here.Hope this helps.
> 
> http://outdoorpowerinfo.com/repairs/


Just to add to this the carburetor that is nearest to the one on your engine at the link listed in this post would be the one listed as 790120


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## RichmondDan (Feb 8, 2011)

I just had a brain flash!

I realize that before the engine started to cough and then shut down, I was running it with the tiller tilted all the way forward, so that I could see if the tines were operating correctly. I ran it this way for several minutes, running the tiller forward and back, but tilted up so that the tines wouldn't touch the concrete.

It's possible that I had it so far forward that the float couldn't operate correctly. I think I'll drain and replace the oil, then see if it will start and run in a level (normal) position, before I start tearing into the carb. After all, it did start and run normally, before I tilted it forward to work with the tines.


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## 30yearTech (Sep 14, 2006)

RichmondDan said:


> It's possible that I had it so far forward that the float couldn't operate correctly.


Yes, it's certainly possible if you tilted it far enough that it could have flooded out. Let it sit with the fuel turned on and see if any leaks out of the carburetor. If it flooded from being tilted, it's unlikely that the oil is contaminated with fuel. It would be a good idea to change the oil, if the oil that's in it is same oil that was in the engine while it was stored.


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## RichmondDan (Feb 8, 2011)

*Successful Resolution*

I made sure the tiller was sitting level and that there was no fuel in front of the butterfly valve. I then opened the fuel supply valve and pulled the starter cord two or three times, slowly, with the ignition off. No fuel collected in the carburetor.

I then drained the oil, which was very thin and smelled strongly of gasoline, and refilled with 30W oil.

The engine started on the second pull and ran smoothly for 5-10 minutes.

Apparently, running the tiller tilted up for 2-3 minutes (while observing the tines, forward and reverse) was enough to flood the carburetor and suck fuel into the cylinder, such that it was very difficult to pull the starter rope. In addition to the fuel coming out of the exhaust, it must also have drained down around the piston and contaminated the oil.

Thanks, guys, for helping me diagnose this and remedy the situation without removing and reassembling the carburetor!


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