B&S 5hp Tuning Problems

[viper3508]

I replaced the clutch n my 5hp because the old one didnt have the right size chain sprocket... now the new one is smoking too. the bolt is tight with some washers for added security (including 1 lock washer) just wondering why it'd be smoking?

Also can anyone give me some advice on how to re-tune one of these things... my buddy and I had it running great at one-point and then we parked it for a few mins and afterwards it felt like it lost ALL power... what can I do?

btw we pulled the spark plug and cleaned it with a wire brush on a dermel right before it flew... we ran it for a while pulled it again and it was straight BLACK now after recleaning its not worth a darn on power. we've messed with the choke and it has to be almost closed for it to idle... and putting on the air filter makes it worse.

 

[residentg]

You are running too rich - meaning too much fuel / not enough air. Is your carb adjustable? Lean it out (turn the screw in a bit).

Do you have the correct spark plug? Put in a brand new one - it could be that you have a weak spark. For B&S 5HP Flathead, use Champion RJ19LM, gap=0.030. Make sure that the head threads are not crossed, put antisieze, or at minimum a drop of oil on the threads, do not over tighten, 12-14 ft-lbs is enough. Do not use a dremel to clean the plug, you will ruin it. Next time, use a tooth brush with some carb cleaner (if it needs it). Regap.

As for your clutch smoking, what gearing and what size rear tires do you have? It sounds like you are geared too tall.

Does the kart roll easily when the engine is not running? See if brakes are stuck, or chain is too tight. Are there any obstructions in front of the kart preventing it from forward motion? If so, remove them.

 

[oscaryu1]

You are running too rich - meaning too much fuel / not enough air. Is your carb adjustable? Lean it out (turn the screw in a bit).

we've messed with the choke and it has to be almost closed for it to idle...

Doesn't add up.

 

[residentg]

If a choke is closed, it cuts off the air supply, making the mixture "richer". There must be some other issue - need more info.

 

[viper3508]

well I'll go get a new spark plug and check the gap...

As for the choke we literally have to have it closed to start it and then pull it open a TINY bit to get it to run... if we put the air filter on I have to open it a little more but not much to idle.

The problem maybe the spark plug, however the dremel was on a LOOOOW speed so idk how using a brass wire bristle on a spark plug would mess it up, sandpaper and erasers seem worse.

Maybe a new spark plug and a little more richness will allow me to run the choke all the way open. it is adjustable...

Could it be bad gas cause the spark to dissipate?

 

[Affair_driven]

Plug does not cause a lean condition.
Look for air leak, adjustment problem, clogged jet, faulty float/needle.
Gas loses a lot of it's volatility after 30 days.

 

[residentg]

but, a bad spark plug's symptoms will mimic a rich condition when a reading is taken. Until we know that the plug is good, it will be hard to figure out the issue. Those Briggs 5HP flatheads do not have a float.

 

[viper3508]

the gas in it is WAY older than 30 days... as far as I know its about 8 months old.

I'm changing the gas and plug later this wk when i get back from the beach...

BTW how do you clean one of these carbs? mine is a tube that sticks away from the block and sits over the gas tank... I'll take a picture if needed? Also what is the screw that sits in the middle the choke valve plate and goes through the tube and rests on the gas tank?

 

[Affair_driven]

I say again, plug is not the problem.

 

[viper3508]

why is it not the plug the plug was soaked in gas and black soot?

 

[Affair_driven]

You said it ran with choke on, therefore it's not the plug.

 

[residentg]

it started with the choke on, it did not run with the choke on. I am not saying that it is the plug, but it may be and I want to eliminate that as a problem so we can narrow it down.

 

[Affair_driven]

we've messed with the choke and it has to be almost closed for it to idle

Unless something has changed, this tells me plug is/was fine.
Induction is the problem.

 

[viper3508]

I have replaced the plug and the gas added sea foam to clean it out... then I screwed out the carb adjustment and it runs perfect with choke fully open

thanks for the help

 

[Affair_driven]

then I screwed out the carb adjustment

Nailed it.

 

[residentg]

$5 says that if he puts the old plug back in, that it won't work.