small motor carb/fuel question

[ManDownUnder]

I have a stationary motor, briggs and stratton 5hp... which won't start until I pour fuel into the carb.

When it fires and (rapidly) comes up to speed, it keeps going drawing fuel from the fuel tank as it should.

When I kill the motor and try to restart it, it won;t start again - until I put fuel back into the air intake.

One of the things catching my attention is this; while winding down from full speed (which takes 10 seconds or so due to the generator attached to it) I can flick the thing back on (so it should start)... but it doesn't.

I have minimal (actually virtually no) small motor experience, but the only thing I can think of it the automatic speed controller mechanism - a governor - somehow shutting fuel off when it shouldn't.

Can you guys/gals/persons of other or undecided gender identity let me know what else I should be considering?
Cheers
MDU

[skidMark]

tricky one could be many things..

your carb could be blocked right up and it is only getting the fuel through the intake they generally do rev up higher when they are running out of gas. and then it is possibly only getting just enough to keep it going from the tank.



but your governer could also be playing up.

just my input but yeah i have some experiance with them but i aint no expert ...try this forum these are all guys that use motors like yours and suchlike in homemade scooters.

http://scooters.tziworld.com/ click on msg board and i think you will probably have to join up, but do a search and you will probably find something useful.

hope something in that helps.

Cheers: MA

[Ixion]

Meh. Briggs and Stratton == 4 stroke. There's your problem. Throw it in the dumpster and get a two stroke. Two strokes rule, OK.

(OH, and it's all a conspiracy, dontcha know)

[Sniper]

Ixion, anyone who builds and maintains two smokers should pay you a comission for all the support you give them

Lol

[MSTRS]

Meh. Briggs and Stratton == 4 stroke. There's your problem. Throw it in the dumpster and get a two stroke. Two strokes rule, OK.

(OH, and it's all a conspiracy, dontcha know)
Soap in the mail. You know what to do when it arrives:devil2:

[ManDownUnder]

Soap in the mail. You know what to do when it arrives:devil2:

and if he doesn't - I have a few suggestions... you'll want to make sure there are no sharp edges

[Motu]

What sort of carb does it have? If it has a carb like the lawnmowers where the carb sits on top of the fuel tank things could get more complicated as they use a diaphram type pump like a chainsaw to lift the fuel.Anyway - strip and clean the carb,idle passages too if it's got one,then refit.The most important thing about starting small engines is they must be on full throttle,so check the govenor setting and give it full throttle on start.Dunno what govenor set up you have,sometimes you can just increase spring tension.Some of these small B&S motors are just horizontal shaft vertions of the lawnmoer motor,some will be a bit more conventional with overhead tank and mechanical govenor.

[ManDownUnder]

What sort of carb does it have? If it has a carb like the lawnmowers where the carb sits on top of the fuel tank things could get more complicated as they use a diaphram type pump like a chainsaw to lift the fuel.Anyway - strip and clean the carb,idle passages too if it's got one,then refit.The most important thing about starting small engines is they must be on full throttle,so check the govenor setting and give it full throttle on start.Dunno what govenor set up you have,sometimes you can just increase spring tension.Some of these small B&S motors are just horizontal shaft vertions of the lawnmoer motor,some will be a bit more conventional with overhead tank and mechanical govenor.

Yup - carb over the fuel tank on this one, and a governor linkage that attaches back to the bottom end housing (I'm guessing some crank speed arrangement...). I'll check it out and give it a go

Cheers Motu - remind me to pay you back for the couple of favours you've done me over the year...
MDU

[Motu]

One trap with those motors is they won't run without the airfilter - or more correctly the mounting screw....so just put the bolt in and you can run it without the filter.Check the choke,they are plastic and break...it has to shut when the motor stops.If it's lawnmower based it may just have a windvane govenor,they give no trouble.And again it must be one full throttle to start,the govenor pulls it back.