Rebuild or High Perf. Carburetor Source

#1
Hey guys.....I know my old 1976 B&S 5hp will run now. I just can't get it to stay running any longer than a couple of seconds. Tank is clean and full and the diaphragm has been replaced. All passages in carb look clean. pour gas in carb or use a little ether, and she starts on 1st or 2nd pull and runs for a second or two and then dies.

Apparently the old Pulsa Jet carburetor needs a rebuild beyond my technique. In case it matters, it is the one with the pull slide choke. I also thought about getting a new one (maybe a high performance if there is such). Would that be ok for my engine? I'm doing a restoration (not rebuilding engine unless I have to) of the Minibike, so I want this thing to be spot on.
 

trinik7597

Active Member
#2
hey red , i just got done doing a four horse same exact issue :thumbsup: did you fill the top tank where the short pick up tube sits when you put it back together :shrug: you need to its like priming a pump .
 
#3
hey red , i just got done doing a four horse same exact issue :thumbsup: did you fill the top tank where the short pick up tube sits when you put it back together :shrug: you need to its like priming a pump .
You should NOT need to do this^ :no:, however, Briggs recommends that you completely fill the fuel tank THE FIRST TIME you start it and to make initial carb adjustments.
Pulsa-Jet carbs are really pretty simple and you should be able to "rebuild" it as needed yourself.(There is not much to "rebuild")
Make sure that the fuel pick-up tubes are clear and (especially) that the screens on the end are clean/clear. (CAREFUL- they are VERY fragile- DO NOT use high pressure compressed air!)' Don't ask how I know!:doah:
Did you check (and replace if needed) the mixture adjusting screw? Is the tip bunged?
After you remove the adjusting screw there is a small brass jet- unscrew it and remove it and clean the 2 tiny passageways. You say "all carb passageways "LOOK" clean? Did you actually clean the carb?
Michael
 

trinik7597

Active Member
#4
hey michael, i am going from my experience as i just went through this :thumbsup: cleaned everything replaced all gaskets , diaphram , jet ,needle valve etc. put back together filled tank no start was not picking up fuel. took back apart went through it again no blockage anywhere put some gas in the upper part of the tank put it back together set mixture at three turns out as it was the first time i tried it starts right up and runs fine :eek:ut: if he does this i bet it starts with out pouring gas in the carb
 
#5
hey michael, i am going from my experience as i just went through this :thumbsup: cleaned everything replaced all gaskets , diaphram , jet ,needle valve etc. put back together filled tank no start was not picking up fuel. took back apart went through it again no blockage anywhere put some gas in the upper part of the tank put it back together set mixture at three turns out as it was the first time i tried it starts right up and runs fine :eek:ut: if he does this i bet it starts with out pouring gas in the carb
I did dissaemble the carburetor (mixture needle, seat, and jet), and also took the diaphragm back out. Shot carb cleaner through everything and used compresser air to clear the passageways. Everything seemed clean and good to go even before that. I can't reinstall and try it because I need an intake carb gasket to put back. I left it back home away from my engine.

I did see a High Performance Carb on ebay (pulsa jet style). It is all clean and polished and ready to bolt and go, and for the money could I just not go with that one and keep this one for a spare?
 
#6
hey michael, i am going from my experience as i just went through this :thumbsup: cleaned everything replaced all gaskets , diaphram , jet ,needle valve etc. put back together filled tank no start was not picking up fuel. took back apart went through it again no blockage anywhere put some gas in the upper part of the tank put it back together set mixture at three turns out as it was the first time i tried it starts right up and runs fine :eek:ut: if he does this i bet it starts with out pouring gas in the carb
Understood. I am not saying that your technique will not work, simply stating that you should not NEED to do it. If the carb is working properly shouldn't need to do that, as the first few pulls of the starter cord will "pump" gas up into (and fill) the small reservoir cup at the top of the tank.
Redfarmer, another thing to check for is any cracks or hole in your fuel pickup tubes, especially if they are the plastic or clear vinyl types. If you draw ANY air from there it is a no go.
Michael
 
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#7
Thanks for the heads up on the cracked tubes. Yeah I did see what I thought MIGHT be a crack on the long tube (where it meets the metal tube about halfway up). I scratched it with my nail and it doesn't feel like a crack. The tube is an off white/yellow color and the questionable area is a black line about 1/4 inch long. It almost looks like the black material that was used to seat the short tubes threads. Maybe it is a crack???

If so, how do you go about changing that tube. The short one was easy enough....just unscrew it. But the long one is different.


Here is that performance carburetor I was talking about.....should I get it or will it not work on my engine??? It sure looks NICE! (and I wouldn't have to clean and polish and rebuild mine)Briggs Raptor Blueprinted and Flowed 5 HP Carb Racing Kart Cart Carburetor | eBay
 
#10
Oh really?? I emailed the seller a question about that and he said it would work with gasoline with a needle (or jet) change. He said he could supply those as well. Still not a good idea??
 
#11
Oh really?? I emailed the seller a question about that and he said it would work with gasoline with a needle (or jet) change. He said he could supply those as well. Still not a good idea??
Be REAL CAREFUL here!!
Generally, most Raptors carbs for alcohol have had the tiny fuel ports ("cat's eyes") under the removable brass jet drilled out (oversized) to accommodate the increased fuel flow needed with methanol. These ports are part of the carb casting. Once they are drilled it is permanent.
Of course an EBay seller would NEVER lie, right!?:deal:
Michael
 
#12
gotcha....I will stick with my stock carb then. Will have to figure out how to replace that tube (or both I guess) and do a full rebuild. I was also worried about soaking the carb in the Berryman's Carb Dip because there is a plastic ring over the air cleaner intake that I can't figure out how to get off.
 
#13
hey red , talk to 125ccCrazy he is a member here he can probably be of assistance very nice guy just pm him . as far as looking nice and polished that is nothing you can not do yourself

Michael is right about some ebay sellers :thumbsup:
 
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