View Full Version : 8HP B&S - Won't start when hot


quid_non
11-26-2007, 02:02 PM
Hi All!
Got an ~13 yr old 8HP B&S (model 192412 type 016701) runnning a 4500W genset. I'm the only owner and keep it in good shape. In infrequent use, in the past, no issues at all with this unit. I'm now using it at a remote site on a near daily basis. Starts fine when cold, runs great - but when I kill the engine to refuel or take a break, it is almost impossible to restart. If I let it cool down, it will start. I've read about vapor lock - it this a possible problem? If so, is their a solution? Should I consider rebuilding the carb?

Thanks for any help!
Best
Wayne

justin3
11-26-2007, 04:19 PM
I would start by checking spark when the engine is warmed up and you cannot restart it. This would tell you wether or not ignition is a problem.

glenjudy
11-27-2007, 11:05 AM
do you choke it at all when you try to restart it after taking a break ?? I would remove plug after it fails to restart and see if it is wet or dry. While you got it out, reattach to plug wire and try to start engine while grounding the plug to head to see if you have spark. this would be one place to start to diagnose problem.
hope this helps,
thanks,

quid_non
11-27-2007, 07:17 PM
Thanks for the help justin and glenjudy.
I"ll check the spark after it's hot - that an easy and good idea.

I've tried choking it - makes no difference, but never pulled the plug to see if it was wet or dry - I like these ideas - easy!
Best
Wayne

quid_non
11-28-2007, 07:37 PM
Quick follow up -
1. Good spark when hot (but still wont start)
2. Plug is bone dry when fully choked after several pulls.

One note, after several pulls, fully choked, I began to smell gas (knew it was flooded) then removed the plug. It was dry!

After more pulls, it coughed, then started - but it still is a beast to start hot!

oscaryu1
11-28-2007, 09:48 PM
Quick follow up -
1. Good spark when hot (but still wont start)
2. Plug is bone dry when fully choked after several pulls.

One note, after several pulls, fully choked, I began to smell gas (knew it was flooded) then removed the plug. It was dry!

After more pulls, it coughed, then started - but it still is a beast to start hot!

Unless it's overheating and evaporating the gasoline when not running...

Make sure all the carburetors and jets are all clean and running smooth. Try increase the fuel in the carb too...

pyro_maniac69
11-29-2007, 01:23 AM
when it dies take off your gas cap, I bet you gas cap isn't venting the way it is supposed to be, and is vaporlocking the motor

quid_non
11-29-2007, 05:48 PM
Thanks for the suggestions - I'll manually vent the cap before I shut it off to see if that helps. If it does, that's a simple fix!!

glenjudy
11-30-2007, 10:10 AM
We’ve about exhausted the easy stuff, except maybe for a new RJ19LM plug.
Would be interesting to do a compression check when cold prior to start and then just prior to restart. Might point out valve tappet clearance problem.
Make sure nuts/bolts holding carb to engine are good and snug.
Any 13 yr old engine with infrequent use is a candidate for a thorough carb cleaning.
If careful, you can completely disassemble, dip carb body in carb dip for a couple of hours, blow out all orifices with carb spray can, blow out with compressed air, then reassemble.
Would be good idea to replace fuel lines and fuel filter, if it has one.
Carb kit for this model is pricey, $30+, if you wish to reassemble with new parts.
Hope this helps,
Thanks,

quid_non
12-01-2007, 07:53 PM
Thanks for the comments - I do have a compression guage, so what you suggested Glenjudy is easy and do-able - thanks. Can you recommend a good carb dip solution? I trpically use a water based parts cleaner, but always interested in good alternatives.

One thing, I "switched" to one of the new "lifetime guarnatee everstart" E3 plugs some time ago. Any experience or comments about these? They "seem" to work well, the electrode desing is radically different than a conventional plug.

Thanks for the time!
Best
Wayne

glenjudy
12-01-2007, 08:27 PM
Some use Berryman's dip, some use Gunk, some use NAPA (I forget the #), I've used a gallon of Berryman's for a couple of years, next gallon I'll get will be Gunk....
I only mentioned the plug so to rule out your current plug, if you're comfortable about having good spark with the E3, keep it.
thanks,

prawncatcher
12-05-2007, 05:13 PM
Hi. I had a honda GX160 with exactly same prob. did everything on the carb to solve problem but no joy . I changed the pickup , working fine since . I dont know if the B&S engines have a similar system , just a thought..

quid_non
12-06-2007, 09:37 AM
Thanks for the note prawncatcher. When you say pickup, are you referring to the ignition module that above the flywheel?

prawncatcher
12-06-2007, 04:38 PM
Yes that's it .The coil that detects the magnet on the flywheel as it passes by..

dhoey33
12-09-2007, 12:19 PM
I have an 11 HP B&S with the same problem, there is a certain temp range on those older engines that once they're shut down they really just don't want to start back up. Believe it or not, when I turn mine off to refuel or take a break, I park it in the shade. It makes all of the difference in the world also what helps, and I found this out on accident while checking for spark, is to remove the spark plug and crank the engine through a few cycles. Reinstall the plug and she'll start right up! Cranking the engine with no plug really helps cool the inside of your engine and helps to get rid of whatever type of vapor lock problem that could be occuring inside. Hope this helps you out, you have and old briggs they are great but need a little special attention sometimes, don't give up on it!

quid_non
12-10-2007, 10:38 PM
Hi dhoey33!
Thanks for the comment, interesting! What you describe does fit my problem - I'll try your solution and see how it works for me. Thanks for sharing!
Best
Wayne