KZ750b intake boot leaking

Replace them. Even though the outside may be smooth and pliable, very fine hairline cracks from heat will occur on the mating surfaces of the holders where they seal against the cylinder head. Applying goo on them is not a good permanent fix. My originals looked like new on the outside but those mating surfaces had many very fine (nearly microscopic) cracks that were causing poor idle. I replaced them and presto-chango - no more problem. Ed

I used Permatex form-a-gasket #1 on my KZ1000 and they have held for over 400 miles so far. I used it as a temp. fix until I could order some new boots from Z1 but now I'm just going to leave them alone and see how long they last without leaking.

When I sealed them I cleaned the mating surfaces very well, applied the permatex to the intake boots, let it sit for 5 minutes to tack up, then put the boots in place and used socket head cap screws instead of the original Phillips/JIS screws. I let them cure for two full days before I put the carbs back on. Then the first time I ran it I just let it get up to temp and then let it sit another day. I think the key is to be patient and be sure the stuff is fully cured before you use the bike again.

Thanks for all the tips and the ebay link, I went ahead and ordered one NOS boot so that will be here sometime next week (if it fixes it I will go ahead and replace the left side). I may also give the permatex no.1 a try as well. Here in a bit I am going to see if the black RTV has held up.

kro10000 wrote: I may also give the permatex no.1 a try as well. Here in a bit I am going to see if the black RTV has held up.

I tried some black RTV and the permatex #2 first with no luck. Same method, everything very clean and more than enough time to fully cure....no luck....still leaked. I figured I would try the #1 because it says manifold gaskets on it and sure enough it worked.

I think the key is clean mating surfaces and plenty of curing time. I know sometimes its a real pain to get stuff properly cleaned. Especially when you're under a truck, 110deg outside and all that crap falling in your eyes and face. When that last little bit of old gasket wont come off it gets very tempting to put the new gasket over the top of it. But then you can almost count on leaks between the mating surface and the old gasket.

When I removed the intake boots on my kz1000 there were remnants of paper gaskets on the engine side. So at some time someone had tried to use paper gasket on its, guess it didnt work.

Give the #1 a shot and if it works you will have new boots as spares. Go easy on the sealant, you dont want a bunch of extra stuff gooping out and disturbing the flow of smooth air into the carbs. If it sticks out further than the boot on the inside you should remove it. I dont know if that really effects anything but to me it seems like it would.

One of my boots just started leaking again. I have been pulling the carbs while messing with jetting and such. Had them off 4 times recently. Just had them off to change needle clip position. As soon as I got them back on and started the bike I could tell right away I had a vacuum leak. Little spray of carb cleaned confirmed it. It wasnt leaking before this last time pulling the carbs. So maybe the sealant trick will work if you run the stock airbox (keeps them from moving as much) or dont mess with your carbs much.

Looks like I will be ordering some new boots myself.

If not already done, would assure all the clamps are snug.

Good Fortune!

Patton wrote: If not already done, would assure all the clamps are snug.

Good Fortune!

This isnt my thread but I think maybe that was for me? If not than I apologize :blush:

The clamps are tight, spraying around the clamps showed no leaks. The leak is on #4 cylinder, upper right corner against the head. I put some permatex #2 on the outside in that corner, that will hopefully stop the leak long enough to get the jetting correct. Then I will put on new boots.