2 Briggs V-Twin questions

[Ronno6]

I still seek ideas on the constant necessity of choking to start....even when warm.

I have postulated the theory that, as the jet O-rings do not hold the jets in place and allow them to drop down til the plastic shutoff solenoid sleeve stops them from falling out completely, the fuel can circumvent the jet orifices.
Doe to lower engine vacuum thru the carb generated at low starting RPMs, there is not enough suction to pull the fuel up thru the transfer tube and allow the engine to start. Kind of akin to drawing liquid up thru a hose vs a straw. The straw is much easier.........

I will see if this condition improves after installing new jet O-rings.

 

[motoman]

Thanks for the corrections. It has been over 40 years since I fiddled with the 115's . Perhaps , indeed, my take of .115 mm is wrong as that is a tiny opening . I guess maybe 1.15 mm might work better with the consensus that the jet hole is about .040", or 1.0 mm. Still, then, the distinction of 1.14 vs even 1.18 seems insignificant . Before emissions (on auto carbs) the "accelerator pump" could often be used for cold start. A jab on the accelerator pedal sent a squirt-gun stream of raw gas into the intake throat. No such function on the tractor engines which do not need to accelerate at high speeds ? I should not say this , but my dyt 4000 choke has never failed to start the Intek in 13 years with about 5-8 rotations from cold. I use sta-bil and tractor is garaged. Carb never apart , 10% ethanol. Also( just lucky?) old Intek always starts from hot without choke.

 

[Mad Mackie]

My Scag Tiger Cub with the original B&S engine 44P777 and the repower engine 49M977 need choke for hot restarts.
My Hustler X-ONE with a Kawasaki FX730V of 2012 vintage never needs choke for a hot restart.
The horizontal shaft 18 B&S Vanguard on my GT seldom needs choke for a hot restart.
The 8 HP Intek on my wood chipper needs choke for a hot restart.
Go figure!!!:confused2:

 

[Ronno6]

For grins and giggles I purchased a cadaver (used) carb off an auction site.
The carb was said to have "worked good" when removed from the engine.
Maybe so, but, it was missing the 2 main jets!
"Never had apart" was the response from the seller.

"No way that motor ran well w/o main jets," I told hem, and sent pix.

Now we wait.....

ed...the seller is a stand up guy. He is sending an emulsion tube that is populated w/jets.
So, all may end well after all....

 

[Ronno6]

Well, ALRIGHtY,THEN.................

I have THE definitive answer from Briggs & Stratton:
(In case anybody wants to know..)

Drum roll,please.................................................

The V-Twin carburetors were redesigned from the 1 jet model to the 2 jet model mostly for emissions reasons (Thank you, EPA)
And,FWIW, should you have a carb using the older 1 jet system, no reason (other than emissions) not to use it.

These carbs use jets of 2 different sizes due to a phenomenon known as "Cylinder Lag."
What the heck is "Cylinder LAG?" one might ask..........
I'm sure MOST of y'all know...................
But, for those who don't (like me prior to date code 021317
Cylinder Lag is the reduced power output of the,shall we say, recessive cylinder due to the position of its
connecting rod on the crankshaft being behind the dominant cylinder's respective position.
Briggs always works off the #1 cylinder; it is the dominant cyl.
This being the case, as the #2 fires in short order after #1, its realized power output is somewhat less than good ol' #1.
Hence, in order to minimize emissions.............#2 cyl's main metering jet is a tad leaner than #1's jet.
The B&S Tech verified that my #111 jet is B&S p/n 699732 for the LEFT (#2)cyl;
jet #114 is p/n 699733 for the RIGHT (#1) cyl.

So, turns out that all the mechanics I had talked to were correct, and now I understand how come!

Mystery solved!
Ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh.

BTW, the reason why carb kits are SO expensive in this day and age is that they have been developed to better withstand ethanol gas.
Thanks again, EPA.
Fortunately, I live where non-ethanol gas is plentiful and not terribly expensive (relatively speaking,) but, I still
gotta pay thru the schnozzola for carb kits..........

 

[Ronno6]

After finally amassing the bits and pieces I needed to do the carb once and for all, I opened it up again yesterday.
Careful removal of the float bowl with the carb inverted revealed that, even though the o-rings were brittle, the plastic sleeve between the shut off solenoid and the transfer tube held the jets neatly in place. This provided me with the opportunity to see if I had installed the jets in their proper positions.
Though it was a 50-50 shot, of course, I got it backwards.
So, after righting the carb and allowing the jets to fall out (they did,,,) I installed some new o-rings and put it all back together.
The end result: no apparent change in either the starting or running of the engine......
But, at least I have increased my knowledge base.....

As for the used carb I purchased, the seller sent me another transfer tube with jets installed. Of course, they needed o-rings.

So, the sheet metal is back on, new drive belt and snug steering.
I'm ready for Spring...........

 

[Boudreaux In Eunice La.]

Ok I am gonna reopen this thread............ Here it is 2018 March 4th....


I am working on a V Twin Briggs with a Nikki 2 barrel carb, running way toooo rich... Plugs getting sooty and all Dat good stuff... Hammering more that when I was was framing houses for a living........

The numbers on the jets, which are MICROscopic are 118 on the left and 122 on the right...... If that's the right order....

I do know the holes are different sizes in the jets... 1 for L and 1 for right........

When I took this carb apart the old gaskets were NOT cleaned off the carb body at all...... A complete mess all in all....
The choke spring was out of place and not working right..... A O ring missing from inside the carb for the tube and bowl where they meet...............

I need to read the first part of this thread, since I just scanned the last couple pages........

 

[Boobala]

Hey there Bo, here's some info. on the carb., AND a place to buy the main-jet o-rings is on the you tube page (in the text) and near the end of the video also,

https://ruclip.com/video/I_k1ystbSW...und-on-briggs-and-stratton-intec-engines.html

https://www.youtube.com/watch?v=uPWul3T0fRE

https://www.youtube.com/watch?v=Jvnu_eEGXRM ********* Just found NEWER vids, .. & video of the 3 kits from this place *******


https://www.youtube.com/watch?v=uPWul3T0fRE

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

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

https://www.ebay.com/itm/Briggs-Str...r-Tube-O-Ring-Service-Kit-54832-/172727245163 .. Just located this guys site,on EBay .. CLICK on... see other items while there, to see other kits and o-rings

 

[Boudreaux In Eunice La.]

Thanks Boo,,,,,,,,,,

I need the O rings for the Jets though.... I can get all the other stuff in this guys kit with the regular 75 dollar kit LOL from my Briggs account...

Sorry for the confusion in my post. I was tired and typing too fast.... Those are great vids and the guy is making good money on those kits, Which they are cheaper than Briggs for those MAIN Parts...

I seen a video a long time ago about a guy showing how to install the O rings real easy on the Jets. He had a link for the O rings.... I cannot find that video for the life or death of me LOL....

Thanks again Boo...........

 

[Ronno6]

Hey, Beaux,

These are the O-rings I purchased from McMaster Carr for the main jets:
2mm i.d. 4mm o.d. Durometer 70A (Medium) ASTM D2000, SAE J200 -20° to 250° Black 100ea. 9262K101 6.26/100

These differ dimensionally from those shown in the video, but they worked just fine.
They are also Buna-n rather than Viton.

Seems to me that I used an easy method to install them.
It involved rolling an O-ring onto a small round object, then rolling onto the jet.
I saw it on a video somewhere too.
I'll look for it.

The last gasket set I purchased was from Home Depot. It cost about $50.00
Gasket sets gone sky high due to the materials necessary to stand up to ethanol...........your EPA at work.
I have not used ethanol gas in my mowers since moving to Mississippi 3 1/2 years ago.
I wish I could purchase older gasket sets..........