Carb installation

[Pasta Burner]

Some of you are aware from my other posts that I decided to pull the carbs and inspect for a known vacuum leak and any other obvious issues while I’m at it. Some parts are on order and I’m about to order some more while I’m at it.  But a few questions and clarifications first.

lower carb boots…one is damaged and should be replaced, but looking at them all I’m not sure how to identify which is which.  Two of them have an A3   1  marking the other two are identified differently.  Also can’t make out the logo to look it up.  According to the parts fiche there should only be two types of boots left and right.  Items 1 & 2.

 

Front left and Rear right lower boot holes started leaking oil as I mentioned in another thread, after looking at the parts fiche I’m a little more comfortable with this being normal as those two holes have different bolts, item 7.  Anybody know if leaking oil is normal and or what is different about those bolts?

Vacuum hose, which boot does it go on?  Mine was on cyl 2 but the parts fiche alludes to cyl 1. Also if I were to inspect the “Nozzle” item 11, what would I be looking for?

https://www.youngpowersportslayton.com/oempartfinder#/Yamaha/XVZ13DTC_-_1987/AIR_FILTER/d8f5f585-45e2-4d3b-b62f-0961652755e5/ee08895c-9b91-4375-a316-99127666930e/y
 

[saddlebum]

The hose goes on cyl #1 but you often see it on #2 because #2 is often mistaken as #1 simply because it is the left front cyl. when in fact the left rear is #1  while the left front is actually #2.

Re: the boots there are only 2 part numbers 26H-13586-00-00 and 26H-13596-00-00.  The bike uses two of each.

A1-2, A2-1, and A3-1 are more than likely mold or batch numbers and meaningless to us unless there was a recall on a certain batch related to some sort of defect in that particular batch

[Pasta Burner]

Thanks!  You have confirmed all of my suspicions.  I ended up ordering new boots, that’s why I was asking about South Korean manufacturing.  My existing boots are ok in most respects but I figured while I have it apart why not just do it.

[TTrax]

I replaced mine recently and noticed the difference in the numbers too, but they all worked out. Like @saddlebum mentioned, I think they are mold or batch numbers. Mine worked out fine even though the numbers cast into the boots didn't seem to make any sense to the orientation. I had bought mine from eBay and they were Tourmaster branded.

[Pasta Burner]

22 hours ago, TTrax said:

I replaced mine recently and noticed the difference in the numbers too, but they all worked out. Like @saddlebum mentioned, I think they are mold or batch numbers. Mine worked out fine even though the numbers cast into the boots didn't seem to make any sense to the orientation. I had bought mine from eBay and they were Tourmaster branded.

I just got my parts yesterday and finished the install.  They were Tour Max branded on the box (dealer said K&L when I ordered them, might be related 🤷‍♂️)  I was happy to see made in Japan on the box.  Exact same logo and other markings on the new boots, letters and numbers differed but for sure leads to mold or batch markings.  Everything is running well, first time ever hearing the bike run without a vacuum leak.

Edited October 14, 2021 by Pasta Burner

[cimmer]

Actually the vacuum hose goes from #2 carb boot to the pressure sensor. Also the #2 carb has no adjustment for it as it is the base line and the other carbs are adjusted to it when syncing the carbs. If you reference the service manual for syncing the carbs it even shows the hose going from carb #2 to the pressure sensor.

Rick F.

[saddlebum]

11 hours ago, cimmer said:

Actually the vacuum hose goes from #2 carb boot to the pressure sensor. Also the #2 carb has no adjustment for it as it is the base line and the other carbs are adjusted to it when syncing the carbs. If you reference the service manual for syncing the carbs it even shows the hose going from carb #2 to the pressure sensor.

Rick F.

That is actually #1. Sitting on the bike, the left rear is #1, The left Front is #2, The right Rear is #3 and the right front is #4 and the hose goes to the left rear which is #1 not #2

[Marcarl]

8 hours ago, saddlebum said:

 and the hose goes to the left rear which is #1 not #2

?????

[Pasta Burner]

[cimmer]

If you refer to the factory XVZ13 service manual on Page 2-13 in the top picture it points out that the vacuum hose is connected to carb vacuum port on the boot for carb #2, the left front. And the left rear, #1 carb is showing a plug on its vacuum port. And if you read the sync process in the manual on the bottom of the page, it shows that carb 2 is what you sync the others to.

Rick F.

[saddlebum]

Interesting and yet if you look at the parts diagram the plug is on #2 and the hose comes off #1 as per attached  pic and more complete parts break down PDF.AIR Cleaner 1989 Yamaha XVZ13D VENTURE ROYALE.pdf

 

Edited October 19, 2021 by saddlebum

[Pasta Burner]

This is why I asked where the hose goes…I’ve read all the conflicting documents and am still not sure.  That being said, from a high level logical approach; if the carbs are synced it shouldn’t make any difference 123 or 4.

[cimmer]

 If you notice the parts diagram only show 2 carb holder and 2 air box connectors.  I can see the confusion as they show the carb holder like it is under carb #1 but if you look the vacuum port is facing the wrong way for #1 but the correct way for #2.  I can even see a bit of a line that they use to show where the part connects.

Does it make a difference, most likely not as when you sync the carbs the hose isnt connected to anything at that point.  You still will need to sync carb 1 to 2 then sync 3 to 4 and then sync 4 to 2 to get them balanced. Engine should be pulling vacuum equally from all the ports once that is completed. They key is to make sure you have  part #11, nozzle, in the vacuum line. This helps to smooth out the pulses that are being sent to the pressure sensor to determine the advance that the ignition is using at any given time.

Hope this helps.

Rick F.

[saddlebum]

12 hours ago, cimmer said:

Does it make a difference, most likely not as when you sync the carbs the hose isnt connected to anything at that point.  You still will need to sync carb 1 to 2 then sync 3 to 4 and then sync 4 to 2 to get them balanced. Engine should be pulling vacuum equally from all the ports once that is completed. They key is to make sure you have  part #11, nozzle, in the vacuum line. This helps to smooth out the pulses that are being sent to the pressure sensor to determine the advance that the ignition is using at any given time.

This is true and to be honest over the years I have seen the hose sometimes on #1 and sometimes on #2 and even experimented swapping it around myself and really did not notice any difference. Having it on #2, (if that is were it actually belongs) probably has more to do with location in relation to the sensors location .

Edited October 20, 2021 by saddlebum

[Pasta Burner]

I found I like it better on cyl #1 because the routing isn’t double backed.