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View Full Version : Basic Engine Question - 8HP Briggs won't start


buzzard86
07-21-2007, 08:13 PM
Hey gang -

Not quite lawn related... hope it's OK to post here.

I picked up a generator today with the thought that I would give me some power in my shed and be handy when the power goes out. It has an 8hp Briggs. Guy I bought it from said that he purchased it 10 years ago for emergencies but never wound up using it. Fluids were drained for a move a few years back but it's really hasn't run much in the past few years.

Today I drained what fuel there was in the tank (he said he put some fresh in to try and start it himself a few days ago), I changed the fuel filter, liberally doused the carb with carb cleaner spray and topped off the oil. It will fire if I pull the plug and put gas directly into the cylinder (so I know I've got spark), but quits as soon as this burns off. Fuel filter is clear and I see gas in it, so I presume that I am getting fuel to the carb. Incidentally, carb bowl was lineed with a black gunk that I had to wipe off with carb cleaner, so I presume things were/are gummed up.

Still kind of new to this. What's my next step to try and get this running?

Thanks, in advance.
JIM

Albery's Lawn & Tractor
07-21-2007, 08:16 PM
Take the carb off and clean it. You mean the black gunk didn't give it away.

buzzard86
07-21-2007, 08:27 PM
Take the carb off and clean it. You mean the black gunk didn't give it away.


Yeah, can I claim newbie status and avoid the ridicule??? :) That being said and fearing further well-deserved harassment, what holds the carb on and what product would you recommend that I soak it in?

I know that this is the most basic of engine repairs. I've just never done it before and google didn't help much. Carb is tucked up on this generator so I can't quite see what all I need to unbolt to drop the thing.

:drinkup: JIM

khouse
07-21-2007, 08:31 PM
Don't forget to blow the carb out with compressed air.

Bill Kapaun
07-21-2007, 08:37 PM
Post the engine numbers so we can tell exactly which carb it is.
You can down load an IPL from Briggs which should show an exploded view of the carb etc.
http://shop.briggsandstratton.com/BShopProductListingPage.asp?rsvp=0&PARENTID=0&SessionID=43C7B3A0-6A44-4EB2-B2CC-23B437198A68&MECID=100&CATALOGID=56B2B9A7-283C-11D4-8886-00B0D0203414

fixer67
07-21-2007, 08:57 PM
I would replace the fuel hose as well. Sitting for that long the fuel hose starts to break down. A lot of that black stuff you see is dissolved fuel hose.

buzzard86
07-21-2007, 09:27 PM
Post the engine numbers so we can tell exactly which carb it is.
You can down load an IPL from Briggs which should show an exploded view of the carb etc.
http://shop.briggsandstratton.com/BShopProductListingPage.asp?rsvp=0&PARENTID=0&SessionID=43C7B3A0-6A44-4EB2-B2CC-23B437198A68&MECID=100&CATALOGID=56B2B9A7-283C-11D4-8886-00B0D0203414

It's an 8hp Briggs on a 4000w Coleman generator. Here are the details:

MODEL 197412
TYPE 0150 01
CODE 9702141A

Thanks.

buzzard86
07-21-2007, 09:41 PM
Just checked out the link with the model# and found my manual. However, still can't quite figure out what holds the carb in place. Does the long tube into which the carb bowl bolt is threaded (part# 142) somehow unscrew to release the carb assembly?

Thanks.
JIM

Bill Kapaun
07-21-2007, 09:41 PM
Parts # 142 Nozzle and 147 Pilot Jet (if equipped) are probably clogged up.

buzzard86
07-21-2007, 09:42 PM
Parts # 142 Nozzle and 147 Pilot Jet (if equipped) are probably clogged up.

Sorry, Bill. I think we just crossed paths in cyberspace. Does this #142 come off some how?

Bill Kapaun
07-21-2007, 09:50 PM
The carb "assembly" is everything contain in box 125 in the manual.
The nozzle should be a press fit, but don't try to remove it just yet.
Take the spray tube from your can of carb cleaner and try to force cleaner through the nozzle. You see/hear is "woosh" into the carb air intake body if it's clear.

Restrorob
07-22-2007, 08:58 AM
Jim,

Remove the air filter cover, Behind the air filter you will see two nuts and down below them a screw. Remove all of these and carefully remove the air filter base, Make sure to carefully remove the breather hose (it could be rotten from sitting).

Once the base is off you will see a torx (star) on the end of the two studs, This is where a torx socket is installed to remove the carb mount studs.

If you don't have this torx socket use two regular 1/4" nuts (without the flange) and screw them both on one stud, Jam (tighten) the two nuts together then put your wrench on the nut closest to the carb and remove the stud.

Do this on both studs and the carb will come off, This engine also has a fuel pump mounted on the flywheel cover. Once you get the carb cleaned and re-installed before putting the air filter and cover back in place spray some carb cleaner in the carb and try starting, You may have to do this a couple times to get it to stay running.

It takes eight or so pulls for this impulse fuel pump to fill a empty carb for it to stay running, The carb cleaner prime saves a few of those pulls.

buzzard86
07-22-2007, 09:29 AM
Thanks, guys. I'm going to head back out and tinker with it today. I'll let you know how it goes.

Rob, I was going to PM you directly but was afraid that you wouldn't want to get involved with another one of my small engine projects. :laugh: Still have to enlist your help to make some adjustments to the Scag drive belts but it's running beautifully so, as you can see, I've moved on to other projects.

Thanks again, everyone.
JIM

buzzard86
07-22-2007, 02:51 PM
Update:

I again saturated the carb with carb cleaner and did a few cycles of carb cleaner followed by compressed air. Couldn't tell if I was getting the "whoosh" and it still wouldn't start, so I wound up pulling the entire carb. With the carb off, I can see a mist of carb cleaner if I shoot the air up the jet. However, now that I've got it all pulled apart, I think I'd like to soak it to give it the best cleaning possible.

Can I just submerge the entire carb in solution? And what's the recommended stuff to use?

JIM

khouse
07-22-2007, 03:19 PM
Are you sure you have the carb ALL the way apart ? Make sure you take the main nozzel out. Spray carb and/or choke cleaner in all open ports. Then use 120 pounds of compressed air.

If you want to soak the carb go to NAPA and buy a 1 gallon can of carb soak. Be careful because it will swell up anything but metal or nylon. Once you soak it for about 1 hour then spray it out with 3M brake cleaner then follow with compresed air. Then it would be a good idea to install a rebuild kit. Good luck!

Restrorob
07-22-2007, 05:44 PM
I wouldn't recommend soaking this carb, There is a rubber throttle shaft seal that WILL swell up and either protrude from between the carb body and shaft or cause the shaft to be stiff and hang up.
Then the throttle shaft must be removed to install a new seal, In some cases the throttle shaft butterfly screws break off in the shaft so a new shaft is required.

Look at the tip of part reference #147 pilot jet and make sure it's open, A bristle from a hand wire brush is good for opening this small port before spraying choke cleaner through the tip of it.

On some LMT carbs the main jet is incorporated into the bowl nut Ref. #950 so check that and make sure those ports are open also.

A good proper cleaning with carb & choke cleaner followed by compressed air as others suggested should be plenty clean enough to get this thing up and running.

Good Luck

buzzard86
07-22-2007, 07:03 PM
OK, I carefully read everyone's recommendations (thank you, thank you) and did not soak the carb. I carefully cleaned the carb with just the spray and compressed air and put everything together. Wouldn't you know, it started right up!!!

Ran beautifully for about 2 minutes and then started to cough and sputter. Still runs but not smoothly. I'm presuming that I probably sucked some more junk into the carb. Now that I know how it comes apart, I guess I'll just take it apart and clean it again.

Incidentally, after it started I discovered that the on/off switch is broken and stuck in the on position. Anybody know where I can source a new one?

Thanks again for all of your help, gang.
JIM

Bill Kapaun
07-22-2007, 07:21 PM
Flush the fuel line from the tank.

Restrorob
07-22-2007, 07:22 PM
Check/clean the fuel tank this time and replace the fuel filter.

Look the switch part number up in the IPL you have then enter it in the part search box then click add to cart and purchase it.

http://www.briggspowershop.com/BriggsAndStratton/advancedsearch.aspx

Or you can hit your local dealer.

Also, If the center part of the kill switch is loose/comes out, The kill wire could be dangling around inside the flywheel cover shorting out causing a radical run situation.
I just repaired one last weekend doing this same thing.

buzzard86
07-22-2007, 08:16 PM
Also, If the center part of the kill switch is loose/comes out, The kill wire could be dangling around inside the flywheel cover shorting out causing a radical run situation.
I just repaired one last weekend doing this same thing.

Thanks, Bill and Rob.

Rob, I'm curious... what do you mean by a "radical run situation?" I thought for a brief moment that I may have seen a spark come out of the switch hole (the broken switch handle rattles out so there's just a hole), but didn't see it again and just thought it was an illusion. Wondering now if it may be shorting out.

I did change the fuel filter and drained the tank completely before I began any of this. Also changed the oil.

Do I pull the whole motor housing off to replace that switch? I looks to be mounted directly in the housing.

JIM

khouse
07-22-2007, 08:46 PM
I knew that that seal would swell up like a Puffer fish so that's why I said a rebuild kit would be in order. I think that seal comes in the kit. But Restrorobs right about the butterfly screws breaking off. Look at all the experience you know have cleaning that carb out a few times! I'm not familiar with that kill switch but can't you pull it out the front of the panel?

buzzard86
07-22-2007, 09:01 PM
I'm not familiar with that kill switch but can't you pull it out the front of the panel?

Nah, I doesn't look like it's that easy. The switch is actually sunken into the motor housing, about 4 inches from the spark plug. Can't get what left of it to budge. Looks like I may have to pull the housing and recoil assembly to get at it.

I hope I'm wrong... that's why I posted it up here before tearing things apart. But there doesn't seem to be anything easily accessible that will release the switch.

By the way, thank for the earlier info khouse. I'd planned to go ahead with the good soak followed by the rebuild if it still wasn't running, but looks like the spray may have worked. Thanks for your help, though.

JIM

khouse
07-22-2007, 09:25 PM
Maybe you can just buy a shorting clip. Mount it under a head bolt and push it against the plug. Some have a sharp point that penetrates the boot. I'm not sure of the part number as I did a quick search. But B&S makes them.

Restrorob
07-22-2007, 09:43 PM
Jim,

What I meant by "radical run" is popping/spitting/sputtering/running high then low, Like a plugged carb. would do.

Sorry but the whole housing must come off to get the old switch out, The housing has to come off anyway to do something with the kill wire dangling inside shorting out.
I believe the carb is just fine now but this kill wire is the problem.

But, You must remove the air filter base to gain access to the fuel pump mounting screws and remove them before you can get the housing off.

If you want to go will a kill tang on the spark plug as khouse mentioned it's part# 220197 but you still have to fix the shorting wire.

buzzard86
07-22-2007, 09:58 PM
Thanks, Rob. I was just looking at the schematic and found the part# for the switch. I guess if I have the housing off anyway I might as well fix it with a factory replacement. I think I will indeed put a new switch on and see if that fixes it before I pull the carb again.

Learning lots here, as usual. Thanks again to everyone for their help!

JIM

khouse
07-22-2007, 10:20 PM
Restrorob,
I knew you could come up with the clip part number! Take care.

buzzard86
07-28-2007, 09:56 PM
If the center part of the kill switch is loose/comes out, The kill wire could be dangling around inside the flywheel cover shorting out causing a radical run situation.

Rob -

You were exactly right. I got the replacement switch from my dealer this morning and pulled the motor housing later in the day. The wire had indeed separated from the remnants of the switch and was flopping around inside. I installed the new switch and buttoned everything back up and it runs like a champ.

Thank you.

JIM

Restrorob
07-28-2007, 10:05 PM
You were exactly right. Thank you.

No problem Jim, I just had the same exact problem last sunday on my brother-in-laws generator with the same engine. :cool:

buzzard86
09-09-2007, 01:28 PM
Hey Rob and gang -

Quick follow up question to this generator thread that I started a few months back. Thanks to all of your help, the generator's running good as new.

My new question... can I put a quieter muffler on this thing? It runs great but it's LOUD! I'm using it right now primarilary to provide light in a shed on the back of my property, but the shed's actually much closer to my neighbor's house than my own and I'm sure that the noise is quite noticable to them.

The muffler that's on it now looks almost like a soda can and screws in. Most of the mufflers that I've seen online have an oval connection with two bolts. I looked and it appears that I do have two bolt holes on either side of the opening in which the current muffler is inserted. I wanted to check with you guys first before I dropped the cash into a replacement.

And, I guess most importantly, even if I can swap the muffler do you think it would help?

Thanks again, guys.
JIM

khouse
09-09-2007, 02:06 PM
I once went to a muffler shop and had them make an adapter for an 18 hp engine pipe. Then they sold me a small muffler. I put it all together with proper brakets and you could hardly hear it running. Don't buy a glasspack muffler. Mine was about 8 x 12 x 3 inches in size. All total was about $30.00
This could be an option.

Restrorob
09-09-2007, 02:56 PM
You can install a larger muffler that is intended for your model engine with two screws, It will help a little but will never be as quiet as say a Honda.

There is one other thing you can do that will help a little more, Briggs has a exhaust deflector that will mount over the small holes on the end of the muffler.


http://i107.photobucket.com/albums/m314/Restrorob/BriggsLargeMufflerDeflector.jpg


Cya