Carburetor cleaning help

[marciofm]

93 Vmax

Finally decided to do a carburetor cleaning and need some help deciding on a few issues.
Already disassembled the 4 carbs and other than o-rings and gaskets, definitely need to change at least 1 one the DIAPHRAGM SET | 3LD-1490H-00-00. The other 3 are not as bad but they don't feel too soft.
If someone could give me a hand, ;et me know, so I describe the issues.

Thank you!

 

[82ndCowboy]

If you post what your issue or question is, people can better assist you.
Posting that you need help doesn't accomplish much.
Explain the problem in the simplest way possible.
List the steps you have taken to fix the problem. Then add any questions you have.

You can also try using the forum search feature.
Chances are the exact problem you are having has already been discussed.

 

[leondante]

If you could change all of them would be the best. DO NOT touch those idle gas needles that are inside a hole under the diaphragm cap. They come tuned from factory and I really don't know how the hell put them on point after touching that. I'm creating a thread about it to ask because I want to know.

Be careful not to mix/mess up the rubber plugs that are inside the jets inside. They are a couple of them but three holes. I've had a year of headaches because putting one of them in the wrong hole.

Check the level of gas inside each carburetor after mounting them, and prepare for dissasembling all again if one of them is out of level too much. So be careful with the floating thing that push the needle to close the gas intake in the carburetor, in order not to bend the small plate that push that needle. Sorry I don't know the names of the parts in English.

As you must spread apart all the thing in order to get all done, you'll need a carburetor synchronization tool. Hope you have that, also know (in Spanish) as vacuum meters. You'll need that like a fish needs water. It's not expensive anyways.

You can use this chance to check that all the jets are the correct ones, they are different for front and rear cylinders, at least.

93 Vmax

Finally decided to do a carburetor cleaning and need some help deciding on a few issues.
Already disassembled the 4 carbs and other than o-rings and gaskets, definitely need to change at least 1 one the DIAPHRAGM SET | 3LD-1490H-00-00. The other 3 are not as bad but they don't feel too soft.
If someone could give me a hand, ;et me know, so I describe the issues.

Thank you!

 

[MaxMidnight]

Check the level of gas inside each carburettor after mounting them, and prepare for disassembling all again if one of them is out of level too much. So be careful with the floating thing that push the needle to close the gas intake in the carburettor, in order not to bend the small plate that push that needle. Sorry I don't know the names of the parts in English.

If you are going to check float level best to do this while the cabs are off the bike; juts make sure they are on a level surface when doing it.
Much less of a faff should you need to adjust the needle tab on the float.

 

[marciofm]

Few decisions before assembling carbs...

1. I have bought a Chinese Set for the 4 Carbs on eBay, but after reading different threads I decided not to use them. Picture attached.

2. Then I bought 4 x K&S 18-2879. (I'm going to use Gaskets and rings) Picture attached.

3. Bought OEM 1 x 12R-14105-00-00 "PILOT SCREW SET"
- One Cab had a Pilot Screw in bad shape and missing the o-ring and washer.

4. Bought OEM: 1 x 3LD-1490H-00-00 "DIAPHRAGM SET"
- One carb had the diaphragm harden and tear.

5. I will get OEM: 4 each CAPS (22V-14968-00-00 and 22U-14968-00-00) that seat on the BLOCK JET ASSY (26H-1411A-00-09)
- Original ones seem harden and have a very little play when in place.

The question I have is regarding the other 3 3LD-1490H-00-00 "DIAPHRAGM SET.
They have no tears but they are not flexible as the new OEM I just bought.
They cost $75 each and I am not sure they are available. $300 on diaphragm is really gonna hurt.
Or... I could try using the ones that came on the Chinese Set I first bought, instead if returning them. (paid $42 for the 4 sets).
We don't know how bad the material is, but they look good and fit well on the carb. Picture attached.

Let me know what you guys think about it. Or if anyone used this king of diaphragm.

Thanks!!!

 

[vfours12003]

I bought a cheap set of sliders complete with diaphragms from china and fitted them. The sliders appear to be alloy rather than plastic like the originals. They work fine. I did have to play around with the needle heights though.

 

[marciofm]

I bought a cheap set of sliders complete with diaphragms from china and fitted them. The sliders appear to be alloy rather than plastic like the originals. They work fine. I did have to play around with the needle heights though.

I will change only the small diaphragm (shown on the picture), not the large one.
I've already cleaned on ultrasound all parts.
The idea is not to replace mos parts, replace all O-rings, Gaskets, small diaphragm (4), Pilot Jet screw (1). and 2 Caps (4).

Just to clarify, you changed the small diaphragm (3LD-1490H-00-00) for a Chinese replacement and it worked fine?

Let me know.
Thanks

 

[vfours12003]

I bought a complete kit with all the diaphragms, gaskets and jets.
The only thing I didn't use was the jets.
So yes I fitted the small diaphragms as well. They appear to made of silicone.
The bike runs better than is has for years.

 

[leondante]

Few decisions before assembling carbs...

1. I have bought a Chinese Set for the 4 Carbs on eBay, but after reading different threads I decided not to use them. Picture attached.

2. Then I bought 4 x K&S 18-2879. (I'm going to use Gaskets and rings) Picture attached.

3. Bought OEM 1 x 12R-14105-00-00 "PILOT SCREW SET"
- One Cab had a Pilot Screw in bad shape and missing the o-ring and washer.

4. Bought OEM: 1 x 3LD-1490H-00-00 "DIAPHRAGM SET"
- One carb had the diaphragm harden and tear.

5. I will get OEM: 4 each CAPS (22V-14968-00-00 and 22U-14968-00-00) that seat on the BLOCK JET ASSY (26H-1411A-00-09)
- Original ones seem harden and have a very little play when in place.

The question I have is regarding the other 3 3LD-1490H-00-00 "DIAPHRAGM SET.
They have no tears but they are not flexible as the new OEM I just bought.
They cost $75 each and I am not sure they are available. $300 on diaphragm is really gonna hurt.
Or... I could try using the ones that came on the Chinese Set I first bought, instead if returning them. (paid $42 for the 4 sets).
We don't know how bad the material is, but they look good and fit well on the carb. Picture attached.

Let me know what you guys think about it. Or if anyone used this king of diaphragm.

Thanks!!!

Hello. I suggest to change the same things in all the carburetors, so the parts has the same characteristics and behave the same way. Having only one carburetor with new diaphragm could make that cylinder work different (doesn't mean bad) and will behave erratically. Also one of them going bad is a sign that maybe all of them are already passed out of their date and would be normal to get them bad soon.

So, I would put the original sizes of jets in all of them, no matter original or chinese as long as they have the correct size, and the four diaphragms at the same time, if they are clearly not of the same elasticity and hardness.

I've experience with chinese stuff. Most of the time things work really well and sometimes they fix issues that the original ones have, so I wouldn't fear anything wrong about it. You are not putting in danger your motorcycle with those changes, the biggest risk is more or less gas and better or worse mixture. Is sad that people pay because the brand printed in the bag rather than checking the quality of what they are paying.

Good luck.

 

[marciofm]

I understand your point about the diaphragm. I will definitely change the 4 of them. As I mentioned, I have bought 1 OEM to replace the one that has a tear. But I have 4 from the Chinese Kit.
The picture I posted shows one OEM and another Chinese (both new).
Maybe it's a good idea to use the Chinese ones on the 4 carbs and if it works well, return the OEM. So they have the same behavior on the 4 carbs.

Waiting for the Caps to arrive and start reassembling!

Thanks for the tips!

 

[leondante]

Be really careful with the rubber plugs, as is easy to switch them around the three holes. I've had a year of headaches because not noticing I messed that up. They fit well in the three holes but only two of them must have plugs.

I understand your point about the diaphragm. I will definitely change the 4 of them. As I mentioned, I have bought 1 OEM to replace the one that has a tear. But I have 4 from the Chinese Kit.
The picture I posted shows one OEM and another Chinese (both new).
Maybe it's a good idea to use the Chinese ones on the 4 carbs and if it works well, return the OEM. So they have the same behavior on the 4 carbs.

Waiting for the Caps to arrive and start reassembling!

Thanks for the tips!

 

[marciofm]

This is the picture I took when disassembling. It should be correct since the last time I had the carbs cleaned it was done by a Yamaha mechanic.
The only thing is that the screenshot I used on the original post shows the flat part pointing down, which makes sense.
What do you think?

 

[leondante]

This is the picture I took when disassembling. It should be correct since the last time I had the carbs cleaned it was done by a Yamaha mechanic.
The only thing is that the screenshot I used on the original post shows the flat part pointing down, which makes sense.
What do you think?

Check this message. I posted pictures from the workshop manual there:

https://www.vmaxforum.net/threads/85-vmax-5500-miles.54158/post-542797