Mikuni check valve install-how to without the tool

Roseand

The Weaponizer
Site Supporter
Location
Wisconsin
On my first check valve and grommet, it went in pretty easy with some oil and by pushing it in with my thumbs. The second one though, I just couldn't get it through. I tried using the rounded end of an allen wrench, a rivet, my thumbs, and absolutely everything. Eventually, the plastic piece was messed up and the grommet punctured. I had to find another way, and I ended up snatching up another check valve and grommet from a user. Tried it again with my thumbs and a rivet head this time but it just wouldn't budge so I gave up, but for the heck of it decided to youtube it.
Sure enough, there was a video for it. You spray everything with windex or any kind of lube, it doesn't matter. Then, you take a piece of dental floss and tie it around the recess in the grommet. You set the plastic check valve with the marker side up over the surface, and then put both pieces of the floss through and wiggle it around and pull. It takes a little patience, but eventually the tip goes into the plastic piece and you're able to get the grommet there. In the vid, it looks like he does it all in one shot, but I ended up getting it started through the plastic piece, then took it out and by hand pushing the grommet all the way through the plastic piece, and then retied the floss and went from there.
When I was doing this, I wasn't putting any other pressure on the grommet other than tugging on the floss. He does that in the video..but it didn't work too well for me at first. I ended up breaking the floss twice, but then I retied it and pressed on it with my thumb while pulling on the floss and it went in extremely easy..So that's what I'd recommend instead. Here's the vid, and hopefully it helps somebody like it helped me!
 

Vumad

Super Hero, with a cape!
Location
St. Pete, FL
On my first check valve and grommet, it went in pretty easy with some oil and by pushing it in with my thumbs. The second one though, I just couldn't get it through. I tried using the rounded end of an allen wrench, a rivet, my thumbs, and absolutely everything. Eventually, the plastic piece was messed up and the grommet punctured. I had to find another way, and I ended up snatching up another check valve and grommet from a user. Tried it again with my thumbs and a rivet head this time but it just wouldn't budge so I gave up, but for the heck of it decided to youtube it.
Sure enough, there was a video for it. You spray everything with windex or any kind of lube, it doesn't matter. Then, you take a piece of dental floss and tie it around the recess in the grommet. You set the plastic check valve with the marker side up over the surface, and then put both pieces of the floss through and wiggle it around and pull. It takes a little patience, but eventually the tip goes into the plastic piece and you're able to get the grommet there. In the vid, it looks like he does it all in one shot, but I ended up getting it started through the plastic piece, then took it out and by hand pushing the grommet all the way through the plastic piece, and then retied the floss and went from there.
When I was doing this, I wasn't putting any other pressure on the grommet other than tugging on the floss. He does that in the video..but it didn't work too well for me at first. I ended up breaking the floss twice, but then I retied it and pressed on it with my thumb while pulling on the floss and it went in extremely easy..So that's what I'd recommend instead. Here's the vid, and hopefully it helps somebody like it helped me!

I stopped reading way before the end.

I put a squirt of wd40 on it, then I gently push around the edges of the mushroom side with a punch to remove them.

I put the new one in with gentle pressure in the hole in the back to get it started and gentle pressure around the edges with a punch.

The punch is not sharp. If the punch is sharp, put it on a heavy piece of steel and hit it with a hammer with moderate pressure to soften the tip a little.
 

Roseand

The Weaponizer
Site Supporter
Location
Wisconsin
I stopped reading way before the end.

I put a squirt of wd40 on it, then I gently push around the edges of the mushroom side with a punch to remove them.

I put the new one in with gentle pressure in the hole in the back to get it started and gentle pressure around the edges with a punch.

The punch is not sharp. If the punch is sharp, put it on a heavy piece of steel and hit it with a hammer with moderate pressure to soften the tip a little.
Getting it out is the easy part. You must have good luck putting them in, because I've done similar to what you're talking and it didn't work.

Sent from my XT907 using Tapatalk
 
i had such a hard time, i said phuk it and left it in. i still got a couple bran new check valves from my last rebuild. mikuni 44's. carbs havent skipped a beat yet!
 
Location
NorCal
The dental floss kept breaking on me and I wasn't even pulling all that hard so I used 50lb braided fishing line I had laying around and it worked like a charm! Got both in within 5 minutes.
 

Roseand

The Weaponizer
Site Supporter
Location
Wisconsin
Well once you have it laying around, it's worth its weight in gold

Sent from my SM-G920V using Tapatalk
 

Roseand

The Weaponizer
Site Supporter
Location
Wisconsin
Just make sure you have the right size.. I had a few break even with the rounded end Allen wrenches

Sent from my SM-G920V using Tapatalk
 
Changing those fuel pump valves has become almost a yearly thing. Something seems to krinkle them- sort of develop a pleat at the sealing surface- maybe the ethanol eats them. The last batch of those little rubber retainers I got seem to be a bit harder than usual, fancy tool, Bondhus wrench, poprivet mandrel, hardly anything would work. I will start saving my floss now and try it Andy's way.
 
Location
Kiowa, KS
Last edited:
LOL, I use my ole lady's finger nail dotting tool. It is the same 2mm ball as Mikuni, and cost 99 cents. Can install the new grommets in seconds with it. But my wife is still pissed at me, oh well....
 
Top Bottom