Anything I should look for when rebuilding a 990 carb?

They are pretty Simple, but on youtube there is a video. Just type in cast iron briggs rebuild and the video will be on top of the list. He has some good tips for first time rebuild.

When you go to take the carb apart remember to remove the emulsion tube before any thing else. If you do not remove the tube you will not be able to take the carb apart.

The first thing I would do is to make sure gas is making it to the carb. It is a problem with the 990 because of the gas tank position. The next thing would be to check the point gap since it is so easy to do on these big briggs engines. Over the years I have done a few carb rebuilds on briggs engines just to find out the problem was ignition. If you do rebuild the carb pay attention to the float, check it for cracks, hold it to your ear and shake it and listen for gas sloshing around. And before anyone jumps me about the kit including a new float I will tell you that not all kits do include a float. The kit I got from NAPA did not include one.

The carb is diffentely getting gass, and the engine has good spark.

I took the carb off yesterday and looked at a few of the "car rebuild" videos on youtube, they was a big help.

Next step is to take it apart and see how it looks.

See http://outdoorpowerinfo.com/repairs/briggs_large_two-piece_flo-jet.asp

During reassembly ensure that the tab on the float has the proper bend so that the float sits level (as he shows in the picture). Also make sure you screw in the main nozzle to the proper depth; due to corrosion in the threads it's easy to be tricked into thinking you have it all the way in when it's not.

genefw said:

The first thing I would do is to make sure gas is making it to the carb. It is a problem with the 990 because of the gas tank position. The next thing would be to check the point gap since it is so easy to do on these big briggs engines. Over the years I have done a few carb rebuilds on briggs engines just to find out the problem was ignition. If you do rebuild the carb pay attention to the float, check it for cracks, hold it to your ear and shake it and listen for gas sloshing around. And before anyone jumps me about the kit including a new float I will tell you that not all kits do include a float. The kit I got from NAPA did not include one.

Click to expand...

X2
IMO I would do the points first. Easy fix. Then if you rebuilt your carb . . . Check gas flow from the tank, then make sure your gas tank is clean with no debris in it. New gas line with a filter.

I checked, the gas was definately making it to the carb. Since the gaskets were leaking any, it seemed like a good idea to bite the bullet and reabuild it.

I have it apart now, the youtube videos were very helpful so far.

A rebuild kit for the car is on order at the loca NAPA parts store, it should be in Monday afternoon.

When I took the carb apart, I found some crude in with the needle valve, between it and the jet, so I suspect this was at least part of the problem.

I just finished cleaning the main parts of the carb a short while ago to remove all of the junk that has built up on it.

I will probably just repalce the point and condenser while I have things apart.

Thansk for all of the good information.

I will keep you giys updated.

I picked up the rebuild kit from NAPA this afternoon.

genefw, my kit did not include a float either, but the old one seemed to be in good condition, no leaks, not allot of crude on it.

No time to work on it now, spent most of the day cutting down a couple of trees...

Those *** cedar trees seem to be about as hard as cement...

The carb is back on and the tractor is running allot better. This is probably the best it has ever run!

I checked the points and found that one contact was loose, it looks like when it was pressed in, it was not done very well. For now, I just opened up the gap, becuse woth the contact floating a little bit the gap gets smaller when it moves.

Next step will be to replace the point and condensor.

It looks like I am having a problem with gas leaking from the carb when the moter is off and the valve on the bottom of the tank left open to allow gas to the carb.

For now I am shutting the valve for a temporary fix, but I will need to go back and fix this.

My guess is the needle vlave attached to the float is not closing all of the way. I thought I set the float height correctly, but since I am having a problem, maybe not.

Any suggestions would be appreciated.

Thanks