Nikki carbs

CLStout

Well-Known Member
Joined
Jun 4, 2021
Threads
12
Messages
130
Another issue I'm having is getting the O-ring on the emulsion tube to seal with the fuel tower on the float bowl. It just seems to large in diameter to fit. Is there something I'm doing wrong?
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
91
Messages
11,490
It may have swelled from E10 fuel contact but normally they don't. It will be a tight fit but bowl should slide up into it when it is in the transfer tube.

I don't have any of the 841653 o-rings in inventory to check the sizing on. But I do have the Kawasaki version (which should be the same o-ring) on hand and it is approximately 8.5mm x 14mm x 2.62mm. Note these measurements are thru the plastic bag they are in.
 

CLStout

Well-Known Member
Joined
Jun 4, 2021
Threads
12
Messages
130
Thanks. The O-ring was apparently damaged during factory assembly, but it's not too bad. I just can't figure out why it won't fit up in the emulsion tube. If I put it on the metal tower in the float bowl, it won't allow me to assemble the bowl to the carb body, like it's too tight of a fit for the emulsion tube.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
65
Messages
24,995
They are a very tight fit, I can not assemble them by pressing together with my hands, even with a TINY squirt of silicon spray .
Have bought a replacement tube only to find it was equally hard.
OTOH all that I have done have worked just fine after reassembly
 

CLStout

Well-Known Member
Joined
Jun 4, 2021
Threads
12
Messages
130
They are a very tight fit, I can not assemble them by pressing together with my hands, even with a TINY squirt of silicon spray .
Have bought a replacement tube only to find it was equally hard.
OTOH all that I have done have worked just fine after reassembly
In your experience, was it better to reassemble the carb with the o-ring inside the emulsion tube, or installed on the float bowl?
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
65
Messages
24,995
IT made no real difference
I reassemble them upside down so it is O ring inside the emulsion tube and like I said a touch of silicon spray lube .
To me it seems like they are using an O ring that is too hard but I am not privy to all of the design parrameters of the carb, just one of the mugs who has to clean & repair them
 

CLStout

Well-Known Member
Joined
Jun 4, 2021
Threads
12
Messages
130
Gotcha. I agree, that's a rather stiff rubber o-ring.

I have 2 o-ring kits, one metric and one SAE. I couldn't find a similar o-ring in either kit. I was hoping to find one that wasn't as stiff. Apparently these are made special for the manufacturer.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
65
Messages
24,995
Most O ring kits are neoprene rubber which is not suitable for petrol
In reality they are only good for water or for putting under flanged plugs & caps to prevent them from vibrating loose .
And these are the good ones.
Heaven only knows what the kits from China with no indication of what they are made from are actually made of.
I have been guilty of doing the same thing when walking through the supermarket in brain dead mode.
Last time I opened the box the O rings had sweated and were becoming slimey
Eventually I will throw them all out and put the O rings bought from McMaster Carr in there in place of the 2 drawer units they live in now.

I use a lot of them on my vintage motorcycles behind inspection caps & even the rocker caps to stop them falling off while riding so I have got my moneys worth out of them in the cost saving for replacing all of the plugs I used to use but for motor use they are useless & none of the sizes will fit any tap or other water fitting I own .
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
91
Messages
11,490
And yes I use Master's and Grainger too here for the Nitrile and Buna o-rings. But the o-rings kits I brough 20 yrs ago from JC Whitney are still good today though most of the needed sizes are never in those kits. As a shop Just cant see paying what Briggs want for one the above o-rings as according to my recent price file they are wanting $8 for just one o-ring and Bert you know darn well what they cost from McMaster's although we must buy in multiples.
 
Top