Topic: '78 cb550k - Are my intake manifold boot on far enough?

[toomanybikes]

Resurrecting a bike that sat for several years. Trying to get the carb bank installed correctly and using new intake manifold boots. Everything is lined up but it doesn't look like the boots are all the way onto the metal sleeves.

I've pushed them in as hard as possible multiple times, applied some heat, applied some vaseline and they still won't go any further. The bike starts fine (psyched) and runs without apparent air leaks. I've checked the photos from when I brought the bike home and the intake manifold boot joints seem similar.

So ... are these on far enough? If not, any magic tricks to get them over the groove?

Thanks 

[Scott S]

 Those are not fully seated. Are you sure you have the matched carbs and manifolds? They may just be old and dry.

[DaveBarbier]

Yeah, not fully seated. I normally nose the bike up against the wall and really push on it with heat and some grease. Some guys use a ratchet strap around the front of the motor and intake of the carbs (with wood to protect the mouths). They are directional, those rubber insukators, but it looks like you’ve got them on right.

[RustyF]

definitely not seated.  seating the carbs is an effort...I warmed mine up with a heat gun and still had to work them hard to be seated.  don't run the bike as is

[toomanybikes]

Thanks all. That's what I expected, but was frustrated by the difficulty in getting them on. I'll try some of the suggestions, such as "wheel against the wall", because I was definitely rocking the bike forward when trying to seat them previously.

[Can550]

With time, they develop matting line/ seating spots with carbs. If switched from 1 to 2 or another carb, they may not seat properly. If you pay close attention, 2 and 3 seat different than 1 and 4.

I had similar situation then removed all rubbers and tried them on carbs (off bike) to see which rubber seats all the way on which carb. Accordingly mounted them on intake.

That is possible only if all four rubbers were removed.


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[toomanybikes]

Update - Got it! For me the key seems to have been loosening the strap clamps that attach the intake isolater rubber to the carb. That gave them just a little more wiggle room that did the trick, along with one more try of the ratchet strap.

For all the comments about matching the carb to the isolator, these were brand new so that was not a factor.

Thanks all

[DaveBarbier]

...For me the key seems to have been loosening the strap clamps that attach the intake isolater rubber to the carb...

Ah yes, I assumed that was being done to begin with. You do unbutton your pants before trying to slither into them, right?

[Scott S]

Update - Got it! For me the key seems to have been loosening the strap clamps that attach the intake isolater rubber to the carb. That gave them just a little more wiggle room that did the trick, along with one more try of the ratchet strap.

 Yeah, and for those that may find this in the future, loosen them more than you think they need to be loosened. I've also found that on older, dryer manifolds it helps to loosen then ones at the manifold side too, in addition to the carb side.

[toomanybikes]

As long as we're capturing for future reference, there are a total of three strap clamps per carb, from back to forward: #1. airbox side to carb intake, #2. engine side carb to manifold rubber isolater, and #3. rubber isolater to engine intake manifold.

I first installed the engine side isolator boots onto the carb rack, tightened strap clamp #2 and then installed the carb rack onto the bike. At first I had #1 and #3 completely undone and #2 tightened, not realizing how difficult it would be to get the isolator fully seated onto the engine intake. When I loosened #2, the isolators then had enough wiggle room to seat using the ratchet strap method.

Now to start her up again.

[TwoTired]

Anyone else use silicone lube to reinstall boots?

Cheers,

[Can550]

I use a tad of dielectric grease inside the insulators and every time had good success

I also install insulators on motor side first. Remove, battery box, air filter housing and electrical plate from left side cover to pull out air plenum.

May sound a lot of work but after hurting my knuckles few times, this works best for me.


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[DaveBarbier]

I use the same Dow Corning high vacuum silicone grease I use for the brake pads. The little containers last a long time.

With pods it’s easier to take off/install the carbs on the 500/550. I used to just remove the whole intake runners off their studs so I wouldn’t have to worry about the insulators. Good time to check condition of those o-rings too.

[Scott S]

Anyone else use silicone lube to reinstall boots?

Cheers,

 I used a spray can of white lithium grease until it ran out recently.  Use the straw to spray just  a little bit and then smear it around with my finger.

[Deltarider]

Note that the rubbers on this model should be oriented right. One end shows two thin lines, the other one thin line. No time now to look it up. Maybe somebody else remembers.

[DaveBarbier]

The double lines go on the head side. He looks to have them on correctly.