KZR's Bikes of the Month for 2024

Carb boot gasket?

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24 Dec 2023 15:31 #893106 by lumbee
Carb boot gasket? was created by lumbee
Doing some troubleshooting; super hot exhaust on one cylinder (600 degrees) and wandering idle when I rev the bike. I sprayed carb cleaner around where the boots meet the cylinder head and the rpm's surge. I removed the carb boots and there is no gasket there. Should there be?

Boots are nice and soft so I don't think there is an issue with the boots being cracked.

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24 Dec 2023 16:02 #893111 by Nessism
Replied by Nessism on topic Carb boot gasket?
Partzilla has a parts fishe where you can look up all the OEM parts.  That's how you can immediately tell if you have anything missing.

I'm not sure about every Kawasaki model, but I'm not aware of any that use gaskets on the carb boots.  On my bike, I changed them straight away after purchasing.  If they are original, they should be changed, because even if not leaking now, they will be soon.

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24 Dec 2023 16:34 #893112 by lumbee
Replied by lumbee on topic Carb boot gasket?
The only ever bike that I have wrenched on that had these short of carb manifolds that bolt to the heads are XS650s and they have a gasket. As I mentioned the carb boots look new. I will say the screws holding them on were not particularly tight so the PO may have just done a bad job of reinstalling them. I just put them back on with a light coat of three bond for good measure. I gave the the gorilla grip tightening and I'll let it sit over night and reinstall the carbs tomorrow. Maybe I'll get a Christmas surprise and a smooth running/idling KZ! 

Terrible design to have Phillips head screws holding them on. Really should be hex heads.

I'm not a bike builder, but I play one on the Internet.

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24 Dec 2023 20:47 #893114 by TexasKZ
Replied by TexasKZ on topic Carb boot gasket?
Actually, they are JIS screws, not Phillips, even so, it is very easy to replace them with hex head screws.

 

1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough

www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24

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25 Dec 2023 03:06 #893115 by zed1015
Replied by zed1015 on topic Carb boot gasket?
No gaskets . 
From new the suppleness of the rubber is enough to seal but once they get old and hard a little RTV or similar sealer won't do any harm.
A thin bead on the head and lightly seat the manifold then fully tighten after the sealer has cured and peel off the excess has never let me down..

AIR CORRECTOR JETS FOR VM CARBS AND ETHANOL RESISTANT VITON CHOKE PLUNGER SEAL REPLACMENT FOR ALL CLASSIC AND MODERN MOTORCYCLE CARBURETTORS
kzrider.com/forum/23-for-sale/611992-air-corrector-jets-





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25 Dec 2023 07:43 - 25 Dec 2023 07:45 #893119 by martin_csr
Replied by martin_csr on topic Carb boot gasket?
Terrible design to have Phillips head screws holding them on. Really should be hex heads.  

Those screws have probably been in there a long time, so you'll need to use a good penetrant (not regular WD40). Heat and vibration w a wood block also help. and JIS screwdrivers. Phillips screwdrivers don't fit the screw heads properly.  You'd probably need to use a hand impact driver after doing the preparation treatments.  ps: Vessel brand screwdrivers are pretty nice.
Last edit: 25 Dec 2023 07:45 by martin_csr.

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25 Dec 2023 08:19 #893120 by lumbee
Replied by lumbee on topic Carb boot gasket?
I went out last night after posting and put on a thin coat of three bold and reinstalled the boots so they could cure overnight. Went out this morning after opening gifts with the fam and reinstalled carbs and all seems good now. Spraying around the boots with carb cleaner and the RPMs do not change.

Now to fix the crazy high idle!

Actually, they are JIS screws, not Phillips


I stand corrected. Well played sir...well played.

I'm not a bike builder, but I play one on the Internet.

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25 Dec 2023 19:50 #893132 by TexasKZ
Replied by TexasKZ on topic Carb boot gasket?
I am not so sure about the play, but many folks are unaware of the difference. The result is thousands of badly buggered screw heads by folks using Phillips screwdrivers on stuck JIS screws.

1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough

www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
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26 Dec 2023 06:34 #893143 by Kent Steerwell
Replied by Kent Steerwell on topic Carb boot gasket?
After years of chasing intake air leaks I made gaskets for between the intake boots and cylinder head.
Used common gasket sheet with Permatex Grey on both sides.
See the attached drawing, hope it is clear.
Changed the JIS screws for socket head cap screws.
The bike was transformed.

1979 KZ1000-E1
2003 EX500-D10
Attachments:
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26 Dec 2023 08:23 - 26 Dec 2023 14:38 #893147 by Nessism
Replied by Nessism on topic Carb boot gasket?
Kawasaki uses a raised lip, molded into the boot, to seal against the head, thus eliminating air leaks.  With age, the lip crushes down, and doesn't seal properly.  Contrast that with Suzuki GS bikes, which use a separate replaceable viton O-ring, to seal the boot against the head.  Suzuki bikes are easier to fix, because all you have to do is change the O-ring (assuming the boots are good otherwise.)  With KZ bikes, you have to update the boots...or resort to other means.  

Using sealer or a gasket will help make the seal, but it's a bandaid, and it won't be as durable as a proper boot with the raised lip in proper working order.  I can appreciate that some people don't want to spend too much money, but to me, replacing the boots when they get old is the proper fix.  Do as you will, though.
Last edit: 26 Dec 2023 14:38 by Nessism.
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26 Dec 2023 12:10 #893153 by lumbee
Replied by lumbee on topic Carb boot gasket?
Thanks all for the info. As I mentioned, I think the PO probably replaced the boots as they look pretty new to me. I think the issue probably was they just were not tightened down very well. At any rate, I just synced the carbs and it seems to be running great. Idles low, no hesitation when I crack the throttle and has a nice growl above 6k rpms. Unfortunately its raining out so I can't take her for a maiden voyage around the block!   And of course, we are leaving town tomorrow for a few days to visit family so I guess the anticipation will have to build for a few days.

I'm not a bike builder, but I play one on the Internet.
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