Carburetor Boots - If you never replaced them, check this out.

[ColtMax]

Its been a month that I own this 1997 Vmax with 89000 miles (143000km). Although the bike runs pretty sweet, Idle has always been a little weird. I have been trying to do simple troubleshooting and keep the fixes as little intrusive as possible as I want to enjoy the the last few rides of the season.

Here is what I did so far:

1 - Intake filter cleaning
Result: I found the home of a little intruder in my filter.

2 - Shotgun carb cleaning:
Result: Some tiny bugs or flea were found in the gas drained from the carbs.

3 - Carb vacuum synching

4 - And now tonight:
I am replacing my carburetor boots. I have a set of boots on order from Yamaha, but some nice weather forecast for next week made me order these boots from Amazon.
The Amazon boots look good. I'll compare with the OEM ones when I get them.

Look at these poor boots...



So if you never replaced your carb boots, you might want to plan this sooner than later.
I couldn't find the VBoost joint boots on amazon, so I will replace them over the winter with OEM parts.

Next step in this Idle fix quest will be to adjust the valves, perform a compression test and clean+rebuild the carbs.
Cheers!
Oliver

 

[gentsvmax]

Its been a month that I own this 1997 Vmax with 89000 miles (143000km). Although the bike runs pretty sweet, Idle has always been a little weird. I have been trying to do simple troubleshooting and keep the fixes as little intrusive as possible as I want to enjoy the the last few rides of the season.

Here is what I did so far:

1 - Intake filter cleaning
Result: I found the home of a little intruder in my filter.

2 - Shotgun carb cleaning:
Result: Some tiny bugs or flea were found in the gas drained from the carbs.

3 - Carb vacuum synching

4 - And now tonight:
I am replacing my carburetor boots. I have a set of boots on order from Yamaha, but some nice weather forecast for next week made me order these boots from Amazon.
The Amazon boots look good. I'll compare with the OEM ones when I get them.

Look at these poor boots...
View attachment 95844View attachment 95845View attachment 95846
View attachment 95848

So if you never replaced your carb boots, you might want to plan this sooner than later.
I couldn't find the VBoost joint boots on amazon, so I will replace them over the winter with OEM parts.

Next step in this Idle fix quest will be to adjust the valves, perform a compression test and clean+rebuild the carbs.
Cheers!
Oliver

Caveat Emptor! A few if not many of us have tried "cheap "parts from Amazon and a shit load of other chinese knock-off parts vendors. Search the carb threads for the many discussions and regrets LOL of the guys(me) that took one for the team.
Those boots, made from inferior compounds are all but guaranteed to be either loose, or tight and crack easily and or short.
Other parts of the fuel system, like the fuel pump, marketed at a fraction of the O.E. price that are discussed in those threads and are agreed on by some as an ok gamble.
While N.O.S. is hard to find, it is available and there are a few quality vendors of other specific
carb parts that really need to remain quality for the bike to run right. Think twice, roll the dice!

 

[ColtMax]

Caveat Emptor! A few if not many of us have tried "cheap "parts from Amazon and a shit load of other chinese knock-off parts vendors. Search the carb threads for the many discussions and regrets LOL of the guys(me) that took one for the team.
Those boots, made from inferior compounds are all but guaranteed to be either loose, or tight and crack easily and or short.
Other parts of the fuel system, like the fuel pump, marketed at a fraction of the O.E. price that are discussed in those threads and are agreed on by some as an ok gamble.
While N.O.S. is hard to find, it is available and there are a few quality vendors of other specific
carb parts that really need to remain quality for the bike to run right. Think twice, roll the dice!

Thanks for the feed back, will look at that thread for sure. Mean while I hope those cheap Amazon boots last a few weeks till winter.

 

[MaxMidnight]

Out of curiosity, do the cracks go through to the inside?

 

[ColtMax]

Out of curiosity, do the cracks go through to the inside?

I couldn't see any of them going all the way through in the middle. But they clearly go through at the edges. Will get the bike started during lunch time a see if I notice a different behavior.

 

[Fire-medic]

Will get the bike started during lunch time a see if I notice a different behavior.

That's when you want to try using a can of carburetor starting fluid on the boots while the engine is running and if the RPMs pick up you've found a leak.

 

[ColtMax]

Tomorrow you have toast turkey sausage and corn flakes toes turkey sausage and corn flakes that's the all albums okay yes please yes I'm pretty much sugar orange juice please oh could I have 2% milk with that too please

Posting while ordering at restaurant with voice command on ?
Bon appétit!

 

[Fire-medic]

Haha, yes, the order was being discussed.

 

[ColtMax]

That's when you want to try using a can of carburetor starting fluid on the boots while the engine is running and if the RPMs pick up you've found a leak.

So after reassembling everything and warming up the engine I re-synched the carbs as much as possible. I must say that theidling seems a bit more stable

Then I sprayed the boots with carb cleaner. The replaced boots dont seem to leak, but definitely I have 2 VBoost joining boots that are raising the RPMs when sprayed.

So I guess I'll be hoping that I get a phone call from my dealer about my orders very soon.

 

[MaxMidnight]

I couldn't see any of them going all the way through in the middle. But they clearly go through at the edges. Will get the bike started during lunch time a see if I notice a different behaviour.

Thanks for the feedback.
The point Mr Medic make is valid although I would have done this before ordering the boots to confirm they were the problem.
Whilst I would change them purely for aesthetic reasons then if the cracks don't go through then they are unlikely to allow additional air in.
Anything at the top and bottom would be sealed when the clamps are done up.

 

[for_gdw]

Its been a month that I own this 1997 Vmax with 89000 miles (143000km). Although the bike runs pretty sweet, Idle has always been a little weird. I have been trying to do simple troubleshooting and keep the fixes as little intrusive as possible as I want to enjoy the the last few rides of the season.

Here is what I did so far:

1 - Intake filter cleaning
Result: I found the home of a little intruder in my filter.

2 - Shotgun carb cleaning:
Result: Some tiny bugs or flea were found in the gas drained from the carbs.

3 - Carb vacuum synching

4 - And now tonight:
I am replacing my carburetor boots. I have a set of boots on order from Yamaha, but some nice weather forecast for next week made me order these boots from Amazon.
The Amazon boots look good. I'll compare with the OEM ones when I get them.

Look at these poor boots...
View attachment 95844View attachment 95845View attachment 95846
View attachment 95848

So if you never replaced your carb boots, you might want to plan this sooner than later.
I couldn't find the VBoost joint boots on amazon, so I will replace them over the winter with OEM parts.

Next step in this Idle fix quest will be to adjust the valves, perform a compression test and clean+rebuild the carbs.
Cheers!
Oliver

Going to look at my own this weekend. I have a tickover running issue anyway, with one cylinder popping a hell of a lot, might be air or carb issue. Will see what my rubbers are like, I have looked in UK for genuine - Fowlers sell them @ £35 for one I think! Ebay from £12 for 4 and see some other places selling as good as or better then original for £50, big differences

 

[ColtMax]

Going to look at my own this weekend. I have a tickover running issue anyway, with one cylinder popping a hell of a lot, might be air or carb issue. Will see what my rubbers are like, I have looked in UK for genuine - Fowlers sell them @ £35 for one I think! Ebay from £12 for 4 and see some other places selling as good as or better then original for £50, big differences

Surprisingly my local Yamaha Dealer which sells mainly boats has the best prices on parts. I had one cylinder popping a lot too before changing the boots.