Briggs Vanguard Carb problem

[beenthere]

This 138400 series with nikki carb is not running without being on half choke. Carb kit is $45 but don't know if that is the fix that is needed. Any thoughts? Engine is 3 yr old and has around 100 hours as a log splitter engine.

Did sit with non-ethanol gas for 5 months.. with no problems running without choke at that time.

Any leads appreciated.. before going with the $45 kit.

tks

Engine 138432-0166-E1

 

[Billself]

I had a vanguard engine that kept bending the pushrods not too hard to check pull valve cover and watch valves if they move good and equal then your ok could also do compression check if everything is all good then throw some seafoam in there and run on choke until starts choking out then let the choke off and run for a while then should be good hope that helps

 

[flyerdan]

If the seafoam doesn't do the trick, take the carb apart and check out the jets and passages. A lot of time some crystaline stuff forms in the brass tube venturi jet, and it disrupts flow. They say never to stick a wire or drill bit in a brass part, but I use tip cleaners all the time for this. If you don't have a can of Berryman's handy, it's about the only way to clear them.

 

[tomplum]

I would pull and clean as flyerdan suggested, but would not invest in a kit. the whole carb is 40$ more than the kit. So if you are dealing with corrosion at all- you're better off replacing it. Valves can be sticky on these small OHV engines due to varnish like deposits as well. This is because the valve springs themselves are light and clearances in the guides in a low hour engine are fairly tight. Usually this will presented as a miss, but some Seafoam through the venturi as it runs up can help that too.

 

[beenthere]

Thanks for the suggestions. I will try the seafoam through the venturi tomorrow (after some deer hunting) and see what effect it has.
Also, for the heads up on the carb replacement.
The old 8hp briggs ran that splitter for near 1000 hours for 30 years. Don't think this Vanguard will match that performance, but hope for a few more good years..

 

[/pine]

FWIW...I know this will sound a bit off...but check the fuel tank for water...I had a vanguard that would only run with the choke mostly closed...before I did anything I mentioned it to a mechanic and he immediately said "water in the tank"...sure enough that was the problem...!

 

[beenthere]

Thanks /pine.
I drained the fuel tank first thing when it would only run with choke half on. Then drained the small sediment bowl under the fuel on/off valve, and then drained the carb float bowl. Hope to run the seafoam thru later today.

Put Seafoam through the carb today, and thought I could detect some change for the better. But still needs some choke to run smooth.
Noted in the manual that the fuel shut-off tiny sediment bowl had a screen tucked above it. Removed it and appeared it was clean. No apparent change in operation.
Will find some time to remove the carb and carefully clean it up. Will report findings..

 

[frugalangler]

if it will run satisfactorily on part choke, add a good dose of Chevron Techron the fuel and use, that will help if it's a varnish issue in the tubes, I always do this before tearing a carb apart and about 50% of the time it works.

 

[beenthere]

fa
Thanks, I will look for that product and give it a shot.
bt

 

[Ford850]

I have an old briggs VG that developed carb issues. It took some time, with several treatments, but Seafoam got it running back to normal. I followed the heat soak directions, and also added it to the fuel. I drained most of the fuel and dumped in the SF, enough to make it close to a 50/50 mix. Started it and ran the smoking beast for a couple minutes, shut it down and let it soak for a few minutes, started again, and repeated several more times. Then let it sit a couple days and did it again. Then added more fresh gas and worked it as normal, adding a fairly good dose of SF to the gas. It gradually ran better and better. Now I just add a slug of SF to the tank when I refill.