Briggs / Nikki issue

[wristpin]

BS 215807 3135 101122

Machine had stood unused with fuel in it for two years. Would idle reasonably but hunt badly on full throttle. Could be smoothed a bit with a little choke.
Removed and dismantled the carb and put it through the ultra sonic tank then purged it with carb cleaner. Reassembled it with a new fuel bowl gasket and fuel inlet O ring.
Refitted to engine and it fired up immediately but runs as though on choke, very rich and black smoke etc. No sign of any flooding either on the outside of the carb or in the venturi.
Had the carb apart again but cant see anything amiss.
I'm not very familiar with Nikki carbs but I've come to the conclusion that unbeknown to me something has dropped out and is allowing fuel to go where it shouldn't . I've not got a shop manual but looking at the parts breakdown for the Nikki I cant see any obvious candidate to fit the missing part theory.
Your thoughts would be appreciated.

[bgsengine]

Main jet in the center tube installed correctly? (O-Ring side of the jet pointing towards float bowl, and inserted DOWN IN to the tube assembly before assembling to carburetor.)

[KE4AVB]

+1

Also if that main is loose fitting it would need replacing as those tiny o-rings aren't available separately from Briggs. A loose jet can fall out while rebuilding and also can flooding from not sealing. I just had one yesterday tried escaping down the drain; good I keep a screen over it. It must have been taking pointers from Inky the octopus.

[wristpin]

Thanks for the replies.
Found this and cant see anything on my carb looking like the main jet as illustrated nor can I see it on the parts illustration but its absence would account for the symptoms exactly.

http://outdoorpowerinfo.com/repairs/bri ... i_carb.asp

Going out to the workshop to have a good look. Is it likely to have just fallen out without any prodding or poking?!!

However everything that you say points in that direction.
Does anyone have part numbers for the jet and O ring , the ARI ipl on my UK suppliers website does not appear to show either.

[KE4AVB]

Briggs 215807-3135
The main won't be always inserted from the outside out the transfer tube but from inside as the one I just did sometimes. If this is the case then o-ring end goes away from the main carb body.
In the IPL the main is 117; unless, you need high attitude version.

[bgsengine]

Thanks for the replies.
Found this and cant see anything on my carb looking like the main jet as illustrated nor can I see it on the parts illustration but its absence would account for the symptoms exactly.

Item # 118 Main Jet - Not shown in the "container" box for the carb, but rather off to the side Should be a part number 698788

Going out to the workshop to have a good look. Is it likely to have just fallen out without any prodding or poking?!!

Yes very easily and you'll never see it if you don't know it already exists.

However everything that you say points in that direction.
Does anyone have part numbers for the jet and O ring , the ARI ipl on my UK suppliers website does not appear to show either.

As noted above - the o-ring is not available separately If you go to our home page (PPETEN's home page) and read my article on pressure testing Nikki - the ninth picture down, you'll see the main jet in the center of the tube

They are installed from the carb mating surface side , o-ring end in first - Easy way to do it, clamp carb in a padded vise so the emulsion tube is level and straight up and down, set the main jet o-ring end pointing up, on the end of the emulsion tube, then you can use both hands to steady things and carefully slide the transfer tube center pipe down over the whole thing to mate with the carb, it should keep the main jet from "tumbling" which often happens when you try to just drop it down the tube. a tiny drop of light oil on the o-ring can help it seat firmly in the transfer tube and then it usually will stay in place by itself unless you drop the transfer tube.

[bgsengine]

As noted above - the o-ring is not available separately If you go to our home page (PPETEN's home page) and read my article on pressure testing Nikki - the ninth picture down, you'll see the main jet in the center of the tube

.

making it easier to find: http://ppeten.com/two-minute-drills/pre ... nd-simple/

[KE4AVB]

[quote="bgsengine"][ Item # 118 Main Jet - Not shown in the "container" box for the carb, but rather off to the side Should be a part number 698788 [quote]

BGS that part number and item number is for the high attitude jet; otherwise, it would item 117 and note date code breaks too.

[wristpin]

Thank you all for your contributions.It would appear that the main jet must have dropped out - probably on the trip from the workshop to the u/s cleaner in the utility room - across a gravel yard!
Lesson learnt and new jet ordered.

[bgsengine]

[ Item # 118 Main Jet - Not shown in the "container" box for the carb, but rather off to the side Should be a part number 698788

BGS that part number and item number is for the high attitude jet; otherwise, it would item 117 and note date code breaks too.

Depends on which parts catalog you are looking at I guess *** Hmm actually it must have been a glitch in the catalog I looked at *** - Double checking at Briggs power portal it is coming in as 117 and the part number is different .. I usually refer to the "quickie" parts catalog (the one I used first) as a faster (much) reference but evidently they have a number of glitches that will result in incorrect parts ordering, it appears.

591936 Jet-Main

(Standard) Used After Code Date 08121400

*edit* ----------------------------------------
Copy/paste from the "other" catalog - (Notice it gives no specification for date code changes)
D-118
Jet-Main
Jet-Main
Part #: 698788

Interesting thing is - when I originally looked at it there was only the *ONE* D-118 callout (117 was missing, so I had assumed that it was for the walbro version) going back to it, now it has 8 different jets listed and you can't even tell for which one or for what date code they are for...

Lesson Learned: Always best to take the extra time to log in to Briggs Power Portal and get the *RIGHT* information.. (Which even then is not always 100% correct every time)