Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

Sign in to follow this  
larry8200

Skipping

Recommended Posts

larry8200
I have a 4 HP B&S on my pushmower. One of the newer ones with a priming bulb and no carb adjustments. It starts normally and runs fine for about 45 seconds and starts skipping. The first time, Cleaning the carb fixed the problem, the second time it didn't. I replaced the carb from a simalar engine runnug well but with a bent crank. Runs just the same, 45 seconds and starts skipping. Any Idea's? Magneto? Ghosts? sm01 Thanks for any help, Larry

Share this post


Link to post
Share on other sites
gocart879
i had the same issue with a 8hp briggs, but i didnt swap carbs. it would run good for a minute and then run (skipping) with no load, and run fine under load, which was a smooth idle run. i traced it back to a few things, one was fuel delivery to the carb, check your float etc to make sure the engine isnt being starved. and check your idle screws etc. i could gaurantee its in there. the fact of swapping carbs with no change i think could be coincidence. do you have a filter that could be slowing fuel delivery?

Share this post


Link to post
Share on other sites
SACK
It could be a coincidence, like stated. The bowl screw on those carbs have the main jet in them, so check that screw carefully to make sure it doesn't have a bunch of gunk in it.

Share this post


Link to post
Share on other sites
larry8200
quote:
Originally posted by gocart879
i had the same issue with a 8hp briggs, but i didnt swap carbs. it would run good for a minute and then run (skipping) with no load, and run fine under load, which was a smooth idle run. i traced it back to a few things, one was fuel delivery to the carb, check your float etc to make sure the engine isnt being starved. and check your idle screws etc. i could gaurantee its in there. the fact of swapping carbs with no change i think could be coincidence. do you have a filter that could be slowing fuel delivery?
Hi, Posting a picture here of the old carburator, no float, no bowl, no adjustment of any kind, just the priming bulb and throttle.


Share this post


Link to post
Share on other sites
Chuck_Woolery
Quick question because I just took apart and cleaned a carb like this for my neighbors lawn mower (was brand new and the carb was dirty). How does the gasket/rubber diaphragm arrangement go underneath the carb? Right now I have it as Carb, gasket, diaphragm, then gas tank. The engine runs, but seems like it has a slight miss or stumble every 30-40 seconds (like you mentioned) under no load. It could just be the governor too, but I want to make sure I have it assembled back together properly before moving onto something else. Thanks, Mark

Share this post


Link to post
Share on other sites
larry8200
quote:
Originally posted by Chuck_Woolery
Quick question because I just took apart and cleaned a carb like this for my neighbors lawn mower (was brand new and the carb was dirty). How does the gasket/rubber diaphragm arrangement go underneath the carb? Right now I have it as Carb, gasket, diaphragm, then gas tank. The engine runs, but seems like it has a slight miss or stumble every 30-40 seconds (like you mentioned) under no load. It could just be the governor too, but I want to make sure I have it assembled back together properly before moving onto something else. Thanks, Mark
Yup, gasket next to carb. Whats a game show host doing playing with lawnmowers? That new plug ran OK for an hour or so and then back to it's old tricks.

Share this post


Link to post
Share on other sites
Chuck_Woolery
quote:
Originally posted by larry8200
Yup, gasket next to carb.
Thanks, at least that parts right. Now I gotta figure out what the stumble is.
quote:
Originally posted by larry8200
Whats a game show host doing playing with lawnmowers?
hahahahahahahaha, you know how long it's taken for someone to actually notice who my screen name is. BTW I'm not actually Chuck, I'm Mark. I just picked that name to use on a bunch of internet forums.

Share this post


Link to post
Share on other sites
larry8200
quote:
Originally posted by Chuck_Woolery
quote:
Originally posted by larry8200
Yup, gasket next to carb.
Thanks, at least that parts right. Now I gotta figure out what the stumble is.
quote:
Originally posted by larry8200
Whats a game show host doing playing with lawnmowers?
hahahahahahahaha, you know how long it's taken for someone to actually notice who my screen name is. BTW I'm not actually Chuck, I'm Mark. I just picked that name to use on a bunch of internet forums.
I knew that, I checked your profile and you ended your first post with "Mark" sm01sm01sm01 Maybe I'll try being Chuck Berris

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

×