Wednesday, March 12, 2014

Briggs And Stratton 8hp Carburetor



Hello
Glad to locate this forum. I have a hot air balloon inflation fan with a horizontal shaft Briggs and Stratton 8 hp, AT 3600rpm (SAE j607) Model 190402 Type 2815-01 code 850409 with the bowl type carburetor.
The engine is difficult to start, and requires half choke to run and then it is not up to full speed.
I would like to locate a replacement rebuilt or new carburetor. Or. get a rebuild kit.
If I go with the kit I will need some advice from you.
I have rebuilt several small float carburetors but never this style. I expect that the cab has jelled fuel or dirt internally.
Does anyone her have a schematic and disassembly info.
Are there any special tools required to remove and replace the jet seats etc and other components.
I would appreciate your input.
Thanks
Baribob

Carb kit you need is PN# 492024, if you have rebuilt carbs the parts will make sense to you. 2 notes on these carbs.
1) The main nozzle is located behind the high speed valve. That needs to be removed before you can separate the upper and lower carb body. I suggest a couple if drops of PB blaster and be sure to use a wide enough flat screw driver. If you strip this =major headache. Needless to say same goes for re-assembly- place carb bodies together and then install nozzle.
2) Pay attention to how inlet needle hangs on float, open end must be facing venturi.
Best to start with rebuild thay run about $125
good luck

3-screw-bowl carburetor is part number 390323 ($130), kit 398235 ($25), manifold gasket 27828S ($3). 4-screw-bowl carburetor is part number 490419 (which is no longer available), kit is 492024 ($33). If you disassemble your carburetor to service it then be sure to remove the emulsion tube (nozzle) first before separating the two halves and install nozzle after assembling the two halves upon reassembly. This nozzle does have a special screwdriver but is not absolutely necessary. The nozzle is behind the main adjusting screw (needle).

Does anybody know what the proper float height is for this carburetor(390323)? I've got one myself, and after installing the rebuild kit, the float height is all screwed up.
Thanks,
Julian

Adjust it so that the float is level with the carb body when you turn it upside down.

Originally Posted by smallengineguy
Carb kit you need is PN# 492024, if you have rebuilt carbs the parts will make sense to you. 2 notes on these carbs.
1) The main nozzle is located behind the high speed valve. That needs to be removed before you can separate the upper and lower carb body. I suggest a couple if drops of PB blaster and be sure to use a wide enough flat screw driver. If you strip this =major headache. Needless to say same goes for re-assembly- place carb bodies together and then install nozzle.
2) Pay attention to how inlet needle hangs on float, open end must be facing venturi.
Best to start with rebuild thay run about $125
good luck
The point about the inlet needle hangs on float? What do you mean by open end towards venturi? Would getting this wrong cause the carb to overflow? I have one that is giving me headaches trying to figure out why it over flows.

I've never noticed it to make a difference which way the open end of the clip faces. On stubborn leakers, sometimes you have to dip the end of a q-tip in polishing compound and put it in a drill and polish the seating area if it has the brass seat. If it has a rubber seat, post back.

Originally Posted by cheese
I've never noticed it to make a difference which way the open end of the clip faces. On stubborn leakers, sometimes you have to dip the end of a q-tip in polishing compound and put it in a drill and polish the seating area if it has the brass seat. If it has a rubber seat, post back.
I think it has the brass seat with the rubber tipped needle. I like the ideal of the q-t tip and polish. I have a rebuild kit on the way also. Hopefully new seals and parts will also help.
Thanks for the polish tip. This engine sat for a while and the bowl is a little crusty. I have it soaking in some carb cleaner to see if it will clean up.

I received the rebuild kit today. It has 2 bowl gaskets, the only difference I can see is that one of them has an extra hole in it. I ended up putting that one in the carb as the extra hole lined up with an little opening that runs to the outside of the choke plate, so I figured it must be there for that.
Anybody familiar with the 2 bowl gaskets and whether I used the right one or not? I managed to start my engine, but it is a 7 hp and I don't have it mounted on anything, so I could not tweak the needle valves. It was jumping around a little more than I was comfortable with, so I shut it off.

I'm not sure. I don't remember the last time I even worked on a 7 horse briggs. I'd say if it works well, and doesn't leak, you're ok.

Originally Posted by cheese
I'm not sure. I don't remember the last time I even worked on a 7 horse briggs. I'd say if it works well, and doesn't leak, you're ok.
The top of the carb has relief areas in the casting so the area that the hole exposes does not really get isolated when there is no hole. The only thing I can think of now is that maybe the one without the hole might be better for my tiller application. I'm thinking that having the one with the hole might make it more prone to gas getting splashed into the port that runs down in front of the choke plate in an application where the engine is going to get rocked around. I'll try it out the way I have it. I can always pop it off and swap the gasket if I have any issues with it. I'll just put the other gasket in my toolbox.






Tags: briggs, stratton, carburetor, brass seat, carb body, hangs float, have rebuilt, inlet needle, inlet needle hangs, inlet needle hangs float