Briggs&Stratton 5HP FUN POWER Wont Stay Running.

[OzFab]

Another point to consider, some older B&S engines need the tank to be more than half full to pump successfully...

 

[kevinmcc]

Lol the cart has been just sitting in a heated garage with a bunch of old cars, its basically brand new, I will have to post a pic asap!

 

[kevinmcc]

So I got some time and tried to get the bike started again with no luck. Got fresh gas, cleaned the carb again, took out the foam in the tank and cleaned it out, fresh plug.. this is all i can get it to do.

Im lost, my arm is tired, been yanking on the thing for 10 min.

https://www.youtube.com/watch?v=3BKsJon1v2U

 

[Whitetrashrocker]

How did you clean the carb? Just so nothing is missed. There are tiny passages that can clog up and cause that symptom. Carb cleaner and compressed air can get most but sometimes it needs a submersion bath in a can of gunk. Then attack the small holes with some fine wire strands. Pull one off a wire brush for example, or a strand of copper wire.
My sis's lawn mower did the exact thing. Found a small booger in there.
Can you work the throttle as it's starting to make it rev up? Will it run at a higher rpm range? That gets the carb off the idle circuit and can help with diagnosis.
Little carbs can be so finicky.

 

[kevinmcc]

I got it to run at WOT once today and it ran at about 1700 RPM with my digital tach that hooks to the plug wire, seens a bit low to me. After I tried to get it to WOT by feathering the gas but as soon as i touched the throttle it stalled.


As for cleaning the carb I blew carb cleaner through every little port i could find, including the diaphram area ports, the fuel pickup and i used a small piece of wire in the jet (cant remove it on this carb)

It does seem to be a fuel delivery problem.

 

[Whitetrashrocker]

WOT is 1700?

Does messing with the choke cause any difference?

 

[kevinmcc]

Yes 1700. And in order for it to start for that 3 sec I have to choke it even tho the engine was warmed up.

 

[Whitetrashrocker]

Not getting gas. Simple.

Is the float set properly?
Is the spark plug dry or wet? Color?

 

[Hellion]

It does seem to be a fuel delivery problem.

9 times out of 10 it's the fuel pump diaphragm. I pulled the one from my current 130200 Briggs project and I could say it was still pliable, but it was a stiff "pliable". Of course check the condition of the spring and its cap in the pump and that they're present and accounted for.

Remove the carb again and look for the following:
1. Is there a spring between the carb and the diaphragm (make sure the spring cap is present)?

2. Is the carb gasket and diaphragm mounted correctly; gasket against the carb and diaphragm oriented properly and mounted on the carb.

3. Does the small bowl under the carb have fuel in it? If you have all three, reinstall the carb on the tank and then tip the tank slowly to see if fuel leaks out between the carb and tank. Just tip it far enough to get fuel coming from the carb and tank gap to see if the gasket leaks.
If any fuel leaks out try re-tightening the screws and test again. If it leaks, you have a warped tank. Replace the tank or try sealing all around the carb.

 

[kevinmcc]

9 times out of 10 it's the fuel pump diaphragm. I pulled the one from my current 130200 Briggs project and I could say it was still pliable, but it was a stiff "pliable". Of course check the condition of the spring and its cap in the pump and that they're present and accounted for.

Remove the carb again and look for the following:
1. Is there a spring between the carb and the diaphragm (make sure the spring cap is present)?

2. Is the carb gasket and diaphragm mounted correctly; gasket against the carb and diaphragm oriented properly and mounted on the carb.

3. Does the small bowl under the carb have fuel in it? If you have all three, reinstall the carb on the tank and then tip the tank slowly to see if fuel leaks out between the carb and tank. Just tip it far enough to get fuel coming from the carb and tank gap to see if the gasket leaks.
If any fuel leaks out try re-tightening the screws and test again. If it leaks, you have a warped tank. Replace the tank or try sealing all around the carb.

1. Yes the spring and piece that goes over the spring is present and spring is still "springy"

2. Yes the gasket is oriented correctly and indexed with the down on the carb body.

3. There is gas in the little bowl and no gas leaks out of the tank when tipped, i did actually replace that gasket recently about 3 weeks ago.

Maybe I should just get a new diaphram gasket? I swear it feels very good though the flaps move freely and it isnt stiff at all but I guess that would be the last thing that could be causing this?


Also when I pulld the new spark plug out after the bike ran at WOT at 1700 RPM it was black as night, not with oil but with soot. very rich it seems. The adjustment screw on carb is 1 turn out from lightly seated.

 

[Hellion]

Hey man, we REALLY need photos because troubleshooting across the wide open spaces of the interwebz is almost impossible.

You should take off that entire air cleaner assembly and let us see the carburetor. Do it with good lighting and a steady hand and get us a nice clear photo or two...

It is a Pulsa-Jet carb and has no fuel lines or floats to speak of, just in case anyone was wondering.

1700 RPM is about where the factory setting is for IDLE. So something is terribly (oh my!) wrong with that.

If you don't wanna post photos, or don't wanna take the time to do it or learn how, fine. We can just keep guessing with little to go on. No one here has time for that kind of torture so I would definitely cease assisting someone who doesn't appear to want any real help.

 

[kevinmcc]

So I got back into the garage again just now and worked on it a little bit more and snapped some photos and some videos for everyone.

I took off that side diaphram cover again and instead of using carb cleaner through it, i just stuck my air hose attachment straight down the holes and blew it all out real good and I am not sure if I am just lucky or if that actually fixed the problem but the bike runs and idles now!

BUT the next problem is the RPM. You guys said it should idle at 1700 but mine idles around 800ish but i think it may be too high for the bike cause it always tries to take off on u if u arent sitting on it unless thats normal? lool never had a mini bike before and full WOT is 1800 (in the video below).

I can make it go up to around 2900 if i manually move that little lever, you can see me try to move it in the video below but i was trying to balance the bike on a 5 gallon bucket, film, and not drop it lol, i assume is the govenor arm?

My question is do I have to do some govenor adjustments or is 1800 the max for this engine?


Photos

http://imgur.com/tW01lTs

http://imgur.com/qjdyylU

http://imgur.com/J8mtN0Q

Videos

https://www.youtube.com/watch?v=MMimhWWxDPw


https://www.youtube.com/watch?v=MLMKlDfxkpw

 

[chancer]

Considering those numbers and guessing that the tach is within 100RPMs
Idle is about 850
and WOT 1800.
Lets double those numbers
1700 idle and 3600 WOT With a max of 5800 if you manually open the Gov. (perfect)

I'd guess that tach is counting wrong. By 50%.
Does the bike ride? Cause no Clutch would engage at 800.

If so. I think you are good to go and the tach is off.

 

[kevinmcc]

Considering those numbers and guessing that the tach is within 100RPMs
Idle is about 850
and WOT 1800.
Lets double those numbers
1700 idle and 3600 WOT With a max of 5800 if you manually open the Gov. (perfect)

I'd guess that tach is counting wrong. By 50%.
Does the bike ride? Cause no Clutch would engage at 800.

If so. I think you are good to go and the tach is off.

I did not get a chance to ride it since it is late and dont wanna disturb the neighbors, however the tach in the video I used on my car to verify and it was accurate right on the money. Maybe it doesnt work well with this type of application, not sure. If the numbers were halfed it would be perfect.

Does it sound like 3600 RPM in the video i posted at WOT?

 

[chancer]

Sound is always hard to ascertain on a Computer Video. Especially RPMs.
But at your idle (870) It sounds pretty normal.
Normal idle is 1700ish.

So yeah I guess.

 

[Hellion]

All right, something seems fishy. The idle sounds right. The WOT sounds about right too.

I think the tach is to blame. It is adjustable. Mine has mode settings as thus:

Code 01 - 2 Stroke 1 Cylinder
Code 02 - 1 Stroke Per Cylinder
Code 03 - 1 Stroke 2 Cylinder
Code 04 - Only Hour (Not display RPM)
Code 05 - Reset mode

I suspect you might have the tach set for the wrong type of engine or # of cylinders. To set it, the manual says to press S1 for 4 seconds until 01 is displayed under RPM. Do another "long press" for 02, 03, 04 and so on.

"Once you find your desired spark plug firing pattern, release the S1 button. The default for the standard model is 02 (once per revolution)."

EDIT: the flat plate thing on the top of the carb is your throttle butterfly. The idle speed screw is on the side of it. That may need adjusting; turning the screw in makes the idle speed go up.

 

[kevinmcc]

Okay so an update.

I got the rpm tach to read right. It was in a different setting. It reads 1700 idle and 3600 wot.

Or should I say did... Now it is doing the same thing it has been doing.. Run for 2 seconds and stall.

I don't understand this thing lol.

Do you guys think I can fit a predator engine in this frame? I have never done anything like fitting an engine before it looks pretty much easy but not sure if the mounting holes and the frame is big enough for one.

http://imgur.com/rhkFT8i

http://imgur.com/wwbvEXV

 

[Whitetrashrocker]

Oh jeez.

Did you adjust any thing after it was running?
Fuel filter?

It's much more satisfying to fix what you have than to bolt a new engine in. Its also good learning experience.

 

[kevinmcc]

Nope. Just went to the garage after it sat over night and tried to start it.

Going to get more gas now.. I tore everything apart. Took the tank off and all to clean everything.

 

[kevinmcc]

So I got fresh gas and so far so good... today lol.. We will see how it does tomorrow... This thing is def a pig tho lol doesnt get out of its own way..


I need to tie a string to that little govener arm and rip it when i wanna go fast haha. I want to remove it but really dont wanna tear into the engine and never done anything like that before.