New carb to manifold boots bowing outward when tightened?

Ok so I have looked, searched and googled but couldnt find the answer. I got new Carb boots, that bolt to the motor, NOT the air intake boots. Now they look like oem, but are off ewwbay. I know, I know. But i was itching to ride. Anyway, put them on, snuggly tightened and took a flashlight and shined inside the intakes, to find out the middle of each boot is shining light on either side. As if the boots are bowing outward and not sealing snug. Am i missing something? Or are they just junk?

I tried to tighten them up more considerring if theyre already bowing outward, why not see if tightening them up more would pull them flush. Nope. So, as a fix im boiling them to see if i can seal up the cracks a little enough to ride a few days until my ....used....set comes in on saturday.

Anyway, I know you arent supposed to tighten them up like the hulk, I just tighten them up snug enough to where i couldnt budge them. And yet, still could see the light gleaming through.

By the way, I havent posted in awhile, sorry:(

Are you sure the carbs are installed all the way into the motor? If they aren't, I can see them sagging from their weight and causing your problem.

Without knowing what bike, what carb holders you bought, or if they actually are the right one's for your application.. I will post a pic.

Properly installed carbs taken this week of my 81 Kz100K1.

You could smear a bit of silicone kit or liquid gasket or some such around each manifold before fitting the rubbers. That should get you on the road.

Do yourself a favor and buy some new ones.
Steve
www.jetsrus.com/mounting_flanges/mounting_flanges.html

davido wrote: You could smear a bit of silicone kit or liquid gasket or some such around each manifold before fitting the rubbers. That should get you on the road.

Davido is correct, normally the original carb holders will have an imprint in the mating surface rubber that may not line up again if an old boot is inverted or moved to a different location. Even new holders could use a light smear of sealant to make sure it seals .

Just went through this with an old set of manifolds after squirting starting fluid at each one while idling. All were leaking air...
Let 1211 sealer set up before starting, and immediately followed with a carb sync. Should have new manifolds in the near future.

I am surprised how well the engine responds to the leaner jetting recently installed. Had it stuck in my head that they needed to be rich, given that I have a header and slightly modified top end vs. stock. Been mistaken for a long time, it seems.

RS34 carb setup now: 120 main jets; 15 pilot fuel jets; .5 air jets; and needles lowered (2nd slot from top). Fuel pump starts at around1/2 throttle.
I expect this might need to change somewhat as the weather heats up.

:huh:

Best power is at just lean of peak A / F ratio.

baldy110 wrote: Best power is at just lean of peak A / F ratio.

Baldy is right. Lean is mean, but it can also help blow sh!t up. Cold dense air tends to make a engine run leaner, as you already know. hence more HP. As the weather heats up, the A/F mix tends to fatten up too. I just went from the stock 122.5 mains to 125 mains because of the Delkevic header is obviously letting it breathe a little better. (BS-34 carbs)

I am wondering if I went far enough on the mains. The service manual shows the J1 model used 127 mains.

I'm going to have to take this header off to try to remove some of that discoloration, if it can be done. It's worse than this pics shows, now that I have a few more miles on it.

Thought sealer would work, but had my doubts. This set didn't seal properly against the head when new and temporarily installed in 2015, but I kept them handy for future use anyway.

Should have known they would be a waste of storage space, and time.

Stupid me.

:laugh:

old_kaw wrote:

baldy110 wrote: Best power is at just lean of peak A / F ratio.

Baldy is right. Lean is mean, but it can also help blow sh!t up. Cold dense air tends to make a engine run leaner, as you already know. hence more HP. As the weather heats up, the A/F mix tends to fatten up too. I just went from the stock 122.5 mains to 125 mains because of the Delkevic header is obviously letting it breathe a little better. (BS-34 carbs)

I am wondering if I went far enough on the mains. The service manual shows the J1 model used 127 mains.

I'm going to have to take this header off to try to remove some of that discoloration, if it can be done. It's worse than this pics shows, now that I have a few more miles on it.

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Those SS pipes are gorgeous, bluing and all!
Just do as SWest quite often recommends...

:lol:

If you get the jetting right the pipes will change color.
Steve