The Fakuni thread (Fake Mikuni carb ) with pics

[WFO Speedracer]

So I have been hearing a lot about these Chinese copy Mikuni carbs showing up but I had never seen one in person as of yet, well that changed yesterday .

The 98 GTS I am working on came in with a new carb , it doesn't run right which is why it is here with me for repair , first thing is the ACCELL pump didn't work , that was a bit of paint or something not letting the arm depress , since it has a spring in the system the spring was taking up the slack.

I fixed that yesterday, as stated in the other thread my mind isn't all that sharp at the end of the day , I am a morning person so I didn't put two and two together right off late yesterday afternoon .

Since I had the carb off anyway I pulled the pump side apart to check the filter, I found nothing in the filter as it should be on a brand new carb , what I did find was black paint inside of the carb, yeah weird but the light bulb didn't even blink .

Second thing this is an accell pump carb and everything about the adjustment was off , I played around with it and got it to work but not as well as I would have liked , hint number three accel pump lines were very loose fit and had cheapo wire clamps on them, I pulled them off and use zip ties, the light bulb still didn't even blink .

Something about the wheel setup on the accel pump arm also didn't look exactly right either , one more thing I checked the adjustments for the high and low needles , while the low speed was fairly close to correct the high speed was already a turn out , if you know anything about Seadoos they jet the high speed with the needle fully closed that way all you can do is richen it up , you can't lean the engine out with the high speed adjustment, smart part on their part .

Anyway I water tested it again today still way off , this is when the light bulb went off , this is one of those dayum Fakuni's off of Amazon or Ebay and it's not jetted even close to right , it's definitely not a Mikuni carb .

I will post some pics of how to identify it when I get back from lunch, right now I am going to get a big ass baked potato.

Notice the cheap wire fuel line clamps in the 1st photo , yeah Mikuni does not use those they use Oitker clamps with a proper fit on the hose , you can see the difference the 2nd pic . So far externally that's the best way to tell them apart , I would need a stocker in hand to look at the Mikuni casting stamp and I will have that as soon as he brings me another crab Monday , then I can compare them side by side .

If anyone has anything they would like to add that they have found on these carbs please feel free to post it up here .

Here is one on an Amazon link . https://www.amazon.com/Carburetor-S...1757103390&sprefix=seadoo+carb,aps,185&sr=8-6

 

[Jr.]

Yup, They have been showing up this summer a bunch. For me, when I get sent a motor to build, a lot of times, client supplies parts.
Normally, no problem. But this summer, I have been getting a rash of Carbs, Electrical parts, even fake NGK spark plugs!
So I had to change my policy, I will now only build with Parts I supply, or have JM or other reputable shop send me Authentic parts only!
Amazon / Fleabay has turned into a Nightmare of Crap!

 

[WFO Speedracer]

Agreed I reminds me of the JC Whitney days with car parts , yeah you can get an engine rebuild kit for $300.00 but what do you have a rebuilt engine full of junk parts , I kind of feel the same way about SBT stuff , back when SBT first came out we used them a lot and I installed a lot of engines, then they started to boomerang and almost sank my ship.

These days I will put in an SBT engine if that's what you want but you deal with SBT, you buy the engine bring it to me and return the core and I will guarantee nothing about it except that your ski now has a properly installed but crappily rebuilt engine in it .

I also used engines from PMC North America , same thing the engines boomeranged , the only engines I installed that had zero issues were the ones from New York crankshaft which used WSM parts.

I get it it's a price point item , I have seen those carbs as low as $79.00 shipped , the Mikuni's are like $212.00 shipped , that $79.00 carb is not set up and jetted properly and I don't know if you can ever get it to run correctly , I don't know if it has the wrong size jets in it , the wrong size needle and seat , the wrong popoff spring or a combination of the three , God only knows about the bypass holes and throttle plate angle but I do know that out of the box it's a no go.

This customer has OEM parts laying around , I told him to bring me an OEM carb , preferably a non accell pump carb and I will rebuild it , install it and most likely only have to turn the screws 1/4 of a turn from where they are set , but what I won't do is bump my ass up and down the road trying to rejet this POS Fakuni and make it work.

 

[Myself]

I've had several of those Fakuni carbe through my shop in the last couple years. This spring was the LAST TIME .......I won't mess with them anymore!! It was a set for a '97 XP. I went through them and checked everything. There are no sizes stamped on the jets but I checked them against my size chart and drill bits I use for rejetting. Amazingly, the jets were ok. Popoff came in around 60psi, so had to correct that, high and low screws were ALL at 1 turn out. sync was off a bit. Needles looked a bit off but seemed to work ok. Got them all together, sounded ok on the trailer, water test went poorly. The thing had a low to midrange bog, would NOT hold a steady idle, and just overall power seemed low for a 787. Called the customer and he brought the original carbs which I rebuilt and got the ski running great. THAT WAS IT.........I WILL NOT mess with those junkers again!

 

[WFO Speedracer]

What this one is doing is it idles perfectly and it will run ok up top if you can get it there, I had to partially pull out the choke to get it to plane out so I know it's really lean in the midrange , this ski is just too nice to screw up with a Chitty Chines carb and I was sure engine damage would ensue if I ran it for very long .

On thing I did notice is that the accell pump is not spraying correctly , either the cam that pushes the lever is wrong , the angle on the lever is wrong IDK , I do know if you work the lever by hand it has massive output , but no amount of adjustment will get the correct accell pump shot up to snuff at this point .

I haven't checked the popoff but yes it has all the symptoms of popoff being way too high , it absolutely will not pull through the midrange even after tweaking the accell pump , one thing is for sure here these carbs are going to be great for one thing , creating massive top end damage on whatever they are installed on .

These DIY guys think they are saving money by bolting on theses cheap @$$ parts, what they are going to do in the long run is cost themselves a lot of heartache , misery , lost riding time and money , as I have said all along , take it to someone who knows what they are doing !

 

[WFO Speedracer]

Autopsy time : Here is what I found

1st pic , notice the black paint in the recesses of the carb throttle plate is stamped 120
2nd pic , misalignment on the accell pump lever to the wheel that actuates it
3rd and 4th pics , this shows the travel on the accell pump diaphragm rod , it's not much , notice it also looks bent slightly
5th pic , inside of the carb, black paint, I wonder how long that will last before it start flaking off ?
6th pic , main diaphragm , it looks halfway decent , notice no red tip on the button , all Mikuni diaphragms have a red anodized tip there
7th pic , jet cover , it looks ok but the reed, valve whatever you like to call it is white and possibly the wrong thickness , hard to determine

continued next post :

 

[fastgtfairlane]

I saw a set of silver mikuni sbn 38s for sale on ebay years ago for 75 bucks each. I thought it was fake but decided to try anyways. They ended up being legit mikunis. Still have them today. Ive seen some sbn 46s for sale on Amazon for around 220 or so. You're saying those are the fakunis?

 

[WFO Speedracer]

1st pic , jet cover screws , very thin cheap BS , not stainless
2nd pic, behind the jet cover , nothing exciting to see here
3rd pic , now this one is really nice , the horseshoe and screw that hold in the seat , yeah it's not even there m nice , really nice
4th pic ,inside the fuel pump , nothing drastic but the plastic diaphragm isn't sealed to the gasket at all
5th and 6th pic , pump assy , actually looks fairly decent
last pic , painted inside again , LX stamped in the carb body on the pump side , how long do you give it ?

A few more things I noticed the action of the lever arm is very sticky , when you depress it , it does not spring back all in one action , the needle and seat is very cheap , I doubt it would last very long before it starts leaking , I did not check the popoff because the horseshoe for the seat isn't even there , what would be the point ?

When I tried to depress the lever to open the needle it was stuck , at minimum the needle and seat, lever pin, spring, all the screws, jets and the valve on the jet cover would have to be replaced, then it might actually half@$$ work .

Maybe it's worth $80.00 for parts but I am not seeing any value here really , maybe if you needed a complete accell pump to fix and OEM carb with IDK?

 

[WFO Speedracer]

I saw a set of silver mikuni sbn 38s for sale on ebay years ago for 75 bucks each. I thought it was fake but decided to try anyways. They ended up being legit mikunis. Still have them today. Ive seen some sbn 46s for sale on Amazon for around 220 or so. You're saying those are the fakunis?

No idea on those , I am just posting what I find here so you know what to be on the lookout for ,but as my dad used to say , if it sounds too good to be true it usually is.

 

[Myself]

That midrange transition bog and not getting up on the high speed circuit is that "anti-siphon" flap valve on the jet cover. If that sucker is too thick they'll do EXACTLY that.

 

[WFO Speedracer]

Since I have nothing better in the world to do lol I am probably going to see if I can actually make this carb work , it won't be going out the door on this customers machine though , I won't take that chance ,I will put it on one of my skis down the road and take an OEM carb with me so I can swap it out at the ramp.

I just want to know out of personal curiosity if one of these can possibly be made to work by switching most of the parts out with OEM Mikuni stuff , yes I do realize it is a fools errand .

 

[fastgtfairlane]

As they say "for sheets and giggles"

 

[orangefinger]

I am really curious to see if this carb works and if will keep working in the long run ... I have only come across fake ADA heads so far no carbs, besides the dam fake rebuild kits obviously

 

[WFO Speedracer]

Ok I decided to check the popoff before I attempt anything else here, no dice it would not hold any pressure at all , I tried to replace just the needle ,I made sure it was sprayed with WD40 , nothing, I checked and it is leaking where the seat is put into the carb.

Apparently it is pressed into the carb , all attempts to remove it so far have come up empty , I will attempt to press it out with the hydraulic press and see what's what but if it's a pressed in non-replaceable seat the carb would have to be remachined to accept the OEM needle and seat , not that that isn't doable but the question is , can you drill it cleanly enough to get the o-ring to seal it up , I think you get my drift here .

As my dad used to say : Too much sugar for a dime .

 

[Myself]

The 787 dual carbs I had in here this year had a WAY too thick o'ring on the seats. I had to run in a lag screw, grab it with vice grips, then hammer the vise grips to POP the seats out.

 

[WFO Speedracer]

I tried driving it out from the back side with a punch and hammer , which I have had to do on some other carbs over the years , I also tried to thread the seat with a 6mm tap and pull it our with a sleeve a large fender washer and a bolt , no dice on either method so far , that's why I said hydraulic press , this things in there like swimwear .

 

[Myself]

Dang...........well, you can't expect every 8 year old child in the country to be able to assemble carbs.

 

[WFO Speedracer]

Dang...........well, you can't expect every 8 year old child in the country to be able to assemble carbs.

You right the bright ones are not working at the carb factories .

The customer brought me an OEM carb last night, I ran through it this morning and it was in really good shape , I replaced a few diaphragms in it , that's it , it is back on the ski ready to water test .

 

[Quinc]

I have had good luck with the fake mikuni motorcycle carbs. Normally just have to clean the casting sand out of them. Put one on a rebuilt xr600 and she ran great right out of the box.