Mikuni Carbs on Yamahas Question

[czac]

So I need to try and put a bigger pilot Jet in my 1985's 225DXN Mikuni Carb. The Climer book says My cab is a VM22. so when I look at the carb exploded view on Partzilla, it shows this as the pilot jet as the one i need...
http://www.partzilla.com/parts/detail/yamaha/YP-3H1-14142-20-00.html

and it is seems to be correct because it looks like whats in my carb. but when i try to find one on Ebay typing in the "VM22" i get something totally different. (see pic below)

https://photos.smugmug.com/Other/Yamaha-225-DXN/i-tPKqPqJ/0/L/mikuni%20pilot%20jets-L.jpg


Did Mikuni change these parts since 1985 or so? the only Pilot jets i can seem to find that look like what i have are for the bigger VM28 or VM30 carbs.

[YamaBoss]

Ah, clymers manual is wrong and leading people in the wrong direction again. Your carb is a VM24. Here's a link to any size pilot jet you could need.

https://www.jetsrus.com/a_jets_by_carburetor_type/jets_mikuni_VM28-486_pilot.htm

[El Camexican]

I figured this post was coming when you mentioned jetting in your other post.:lol:

The style you need is the longer one on the left of the screen, BUT! the problem is that there are two types that look like that one. I know this because I keep buying the wrong ones and no one at Jetrus or Sudco can tell me which ones to buy because the carburetors on the YTM’s are proprietary and I’ve been to lazy to figure out which is which.

If you can wait a day or two I will try test some of my jets in an old 225 carb and post photos of the correct one once and for all, but then you’ll need to confirm which style that is with Sudco or Jetrus if you can get them to answer your calls, or emails unless you can tell from their images.

[YamaBoss]

I will get some pictures of the jets I bought from Yamaha vs Jetsrus

[YamaBoss]

The jets on the bottom are from Yamaha, The jets on the top are the ones I bought from Jetsrus, They work perfectly in my carb.

[El Camexican]

So here's the problem, the four shiny jets on the left are new from Jetsrus and fit my carburetors fine. The two dark, used ones in the center are originals from that Yamaha carb. However the two new looking jets on the right of the photo are identical to the others in every way except for the diameter of the tip. They are 2.5 mm in diameter and the jets these carburetors take our only 2.0 mm. To make matters worse you can still screw these oversized Jets into those carburetors, but they don't go in as far. I don't know what carburetor they are intended for, or remember which is which when ordering, but whatever you do make sure that you get the Jets with the smaller tip when you are ordering them.

238074

[czac]

Ah, clymers manual is wrong and leading people in the wrong direction again. Your carb is a VM24. Here's a link to any size pilot jet you could need.

https://www.jetsrus.com/a_jets_by_carburetor_type/jets_mikuni_VM28-486_pilot.htm

Christ! That figures.... lol well there goes a bunch of time wasted looking for info! Lol thanks for the heads up!

[czac]

the problem is that there are two types that look like that one. I know this because I keep buying the wrong ones and no one at Jetrus or Sudco can tell me which ones to buy because the carburetors on the YTM’s are proprietary and I’ve been to lazy to figure out which is which.

That figures... why would they do that? Talk about being confusing!


If you can wait a day or two I will try test some of my jets in an old 225 carb and post photos of the correct one once and for all, but then you’ll need to confirm which style that is with Sudco or Jetrus if you can get them to answer your calls, or emails unless you can tell from their images.


cool thanks that would be awesome!

[czac]

So here's the problem, the four shiny jets on the left are new from Jetsrus and fit my carburetors fine. The two dark, used ones in the center are originals from that Yamaha carb. However the two new looking jets on the right of the photo are identical to the others in every way except for the diameter of the tip. They are 2.5 mm in diameter and the jets these carburetors take our only 2.0 mm. To make matters worse you can still screw these oversized Jets into those carburetors, but they don't go in as far. I don't know what carburetor they are intended for, or remember which is which when ordering, but whatever you do make sure that you get the Jets with the smaller tip when you are ordering them.

http://www.3wheelerworld.com/attachment.php?attachmentid=238074&stc=1

yeah they look different... it also seems they have a ridge in them just above the shoulder .
ill go measure mine too, see what i have. So i guess buying these off ebay isn't worth the effort then? No one lists sizes unless you get lucky!

[czac]

Just curious, what happens when you use these bigger jets? Do they not work at all?

[El Camexican]

Just curious, what happens when you use these bigger jets? Do they not work at all?

The large tipped ones? Well I know you can screw them in a few turns because I did it before I glanced at a second carb and saw how much deeper the smaller tipped jets were seated. I don't recommend trying them, they simply aren't for our carbs.

BTW that line that look like a ridge is just a line, the diameter on either side is the same. Maybe it's there as a way to tell help them apart from the other style?

[czac]

BTW that line that look like a ridge is just a line, the diameter on either side is the same. Maybe it's there as a way to tell help them apart from the other style?

Well I did some digging and yes, it seems like the ones with that Line are the 2.5MM ones... I looked around and found a few on Ebay so I asked the sellers and what I found is when looking for the Ones we'd need, the 2MM tip ones, you'd do a search for "Mikuni VM28/486 pilot jet" or like "VM28/486-*" the star would be the size like 20 or 22.5 0r 30... It seems all the ones I have seen on there that have that Line are listed as "Mikuni N224-103" So it seems thats how they are told apart. I have also seen the bigger ones listed as "CR/YZ N224-103 OEM,TMX,BSR Style"

[czac]

here's a new thought... the holes in the stem... they are pretty much all the same size in the different numbered Jets. I have 3-#20, 1 each of #22.5, #25 and #15 and all but 1 jet have the same size holes, one of the three #20's has smaller holes than all the rest. Funny because it also doesnt have any size stamping or other markings on it. it came in a carb rebuild set I bought and was listed as containing a #20 Pilot jet. It must be just an after market jet. Oh yeah, the #25 jet i have is one of the Bigger ones with the line... lol I had ordered two off Ebay and the 22.5 is good but the #25 is going to be hanging on the shelf...lol or maybe Ill wear it as a necklace or something... "Jet Wear" or "Jet-elry"

[YTZ drew]

Just a thought, but your OEM pilot jet is Yamaha part number 3H1-14142-20-00 which is a number 20 pilot jet for your trike according to Partzilla. Try asking your local Yamaha dealer to find you a 3H1-14142-25-00, which would be a number 25 pilot. If you google that number it shows as an alternate jet for the 225dx, albeit a discontinued part number. I have used this method before when looking for odd jet sizes, find the piece of the OEM part number that matches the jet size and change it to the number I'm looking for. Just a thought, might be easier than playing with Jets r us.

[czac]

Just a thought, but your OEM pilot jet is Yamaha part number 3H1-14142-20-00 which is a number 20 pilot jet for your trike according to Partzilla. Try asking your local Yamaha dealer to find you a 3H1-14142-25-00, which would be a number 25 pilot. If you google that number it shows as an alternate jet for the 225dx, albeit a discontinued part number. I have used this method before when looking for odd jet sizes, find the piece of the OEM part number that matches the jet size and change it to the number I'm looking for. Just a thought, might be easier than playing with Jets r us.

Thanks! Didn't think of that... lol what i did do was go on eBay and found a dealer who has both styles and found out how to tell the difference between the two. So i ordered a few different sizes and a couple bigger sized main jets as well. Now I'm just waiting to get them when i go to work. I had them delivered to my job thinking they'd be a few days in transit. Now hopefully a bigger jet will do the trick!

[czac]

So i bought a few different sized main jets and Pilot jets from Niche cycle supply . com off of E bay (but they have a real website also) and I replaced my #20 pilot jet with a # 22.5 and so far so good. I rode the trike around a little on Sunday and it ran pretty good, didn't bog, didn't pop when I gassed it but it popped a little when i let off the throttle...like it always has but it picked up nice and smooth but the biggest part was I didn't see any cheery red on the pipe but then again, it was in daylight so I will have to fire her up when its a bit darker out to see if she glows. I'm gonna try replacing the #112 Main jet with a #115 and see if that does anything.. and for fun i may try a #25 Pilot jet too! lol. also i measured my OEM carb and it is a 28MM...

https://photos.smugmug.com/Other/Yamaha-225-DXN/i-pZVWZhZ/0/L/2017010411595576-IMG_8732-L.jpg

I guess this is the part or serial number?
https://photos.smugmug.com/Other/Yamaha-225-DXN/i-3Qcz2SC/0/XL/2017010412003514-IMG_8729-XL.jpg

[yaegerb]

that's a flange carb. Mikuni flange carbs only come in two sizes 20 and 22. If you take a set of calipers and measure the inside diameter of the throat (all the way back) you should find that the size to be approx. ~25MM. An easier way to check the size of the carb is you should have 49MM from center of one flange bolt to the other.

From what I see you have a 22MM flange bolt mikuni.

[El Camexican]

You may find this of use if you've got the thing apart.

http://www.3wheelerworld.com/showthread.php/171354-Intake-Manifold-Porting-YTM-200-225?highlight=ytm

[czac]

that's a flange carb. Mikuni flange carbs only come in two sizes 20 and 22. If you take a set of calipers and measure the inside diameter of the throat (all the way back) you should find that the size to be approx. ~25MM. An easier way to check the size of the carb is you should have 49MM from center of one flange bolt to the other.

From what I see you have a 22MM flange bolt mikuni.

So you measure the inside of the carb?? lol Ok i will do that. I did confirm with a Mikuni dealer though that the carbs on the Yamaha three wheelers were made specifically for Yamaha with Yamaha's specs. I have another carb (it was on it when i bought the trike) that is a newer Mikuni carb but its alot smaller.. i will measure that one too. From off the top of my head, when I measured that one (in the same place i measured the one in my pic) iw was like 22 or so MM. But when I take mine off again I will check the inside to see what the size is. why the heck cant they just stamp the size or the part number on these things? lol

[czac]

You may find this of use if you've got the thing apart.

http://www.3wheelerworld.com/showthread.php/171354-Intake-Manifold-Porting-YTM-200-225?highlight=ytm

interesting thread... thanks. I just added a little info to it too. Makes me wonder if a bigger head and cylinder like off a 250 would bolt right on to a 225 block? lol... I have a spare 225 motor that is seized sitting in my garage i have been raping parts off of.... Hmmmm test motor? lol
If this keeps up, I'm going to have to divorce my wife so I wont have to keep hearing all those annoying questions like, "wheres all the money gone?" or "how many of these things do you need?" or "what the hell are you doing out in the garage now?" or the best one... the one that makes me belly laugh when I hear it, "You do know garages were made to park cars in and not to be used as a work shop or for storage right?"
lol I guess thats the difference between people brought up Blue collar and those brought up white collar...lol

[El Camexican]

I have a spare 225 motor that is seized sitting in my garage i have been raping parts off

I believe the main difference between the 200 and 225 is the connecting rod and crankshaft. The heads are the same. Not sure about the cylinder, but I suspect that the added displacement comes from the rod length of the 225.

[czac]

Hmmmm... A 350 motor might fit with alot of welding and swearing and hitting things with hammers. lol