Topic: Gas vs silicone

[Bennie1977]

Ok. Back at it again the problems. So im still in the process of getting my bike together after doing a carb rebuild. I put my carb back on after fighting boots like a mfr. Ended up stripping a few threads attaching the bowl. Now i have it back together and i thought carb 3 was flooding from the float being to high.  Turns out its leaking from the fuel rail between carb 2 and 3. Only  two o rings i didnt change because i didnt want to take the throttle and choke mechanics apart. It screwed me over in the long run. Now, is there any chance i can silicone around the fuel rail tube, or will it disintegrate? Any help on what i should do would be appreciated. Also, i cant get my new air box on my 77 cb750f. Any tips on that too? Seems to be to tight. Last question, what does the valve on the top of the air box connect to? Theres a little circular box that the head connects to behind the carbs, i would assume the air box connects there as well? Thank you.

[evinrude7]

Ok. Back at it again the problems. So im still in the process of getting my bike together after doing a carb rebuild. I put my carb back on after fighting boots like a mfr. Ended up stripping a few threads attaching the bowl. Now i have it back together and i thought carb 3 was flooding from the float being to high.  Turns out its leaking from the fuel rail between carb 2 and 3. Only  two o rings i didnt change because i didnt want to take the throttle and choke mechanics apart. It screwed me over in the long run. Now, is there any chance i can silicone around the fuel rail tube, or will it disintegrate? Any help on what i should do would be appreciated. Also, i cant get my new air box on my 77 cb750f. Any tips on that too? Seems to be to tight. Last question, what does the valve on the top of the air box connect to? Theres a little circular box that the head connects to behind the carbs, i would assume the air box connects there as well? Thank you.

silicone? NO.  replace the o-rings.  put the airbox on in 2 parts.  top first, then add the bottom.  i believe it's a top and bottom unit like on my 76 K. 

[ekpent]

 Heat the rubber boots on the manifold side and the airbox side with a heat gun when taking the carbs/airbox on and off to soften the rubber if its old and make it more pliable and easier to work with. Unfortunately you need to replace those old o-rings on the fuel pipes or if you get lucky they may expand back enough now with some new fuel. Sounds like they are worn out though.

[Bennie1977]

Well f$@#  it was a nightmare getting the carbs back on the boots. Anyone in michigan up for a challenge? At this point id rather pay someone to do it, it was such a pain.  If i do and up doing it, id like to go back through my floats. Anyone know what the spec highy they should be set at?

[FuZZie]

Well f$@#  it was a nightmare getting the carbs back on the boots.

True, but if you have to go through the carbs chasing little bits of silicone that got in the fuel you'll be waking up from that nightmare with the cold sweats.

[Bennie1977]

I just want to ride, and riding weather isn't to far away.  at this point id take it to a bike mechanic. Sadly, no one really works on these anymore.

[ekpent]

 There is a shop in Galesburg Michigan,just east of Kalamazoo called Checkered Past that does vintage bike stuff only. Where in Michigan are you at ?  https://www.facebook.com/checkeredpastcycles/

[evinrude7]

removing the airbox and carbs is a pain in the ass.  however once you figure out how to do and what works for you it's not that hard anymore. 

[pjlogue]

I have used a ratcheting tie down and wrapped it around the head and then back behind the carbs, then slowly tighten it down.  It helps to use silicone vacuum grease on the nipples.  Be sure to align the rubbers with the nipples.  Cyl. #1 should have the #1 on the rubber up, #2 with #2 up etc.  I found just being a little off makes a big difference in alignment.  An extra set of hands helps.  If you can get one side started and seated with the middle ones starting to go in you can tighten the clamps on the seated boot and use a board and mallet and try and seat the other side.  Be careful to have the board flat on the carb inlet so you don't bend/brake the carb inlet.  This approach is a hit or miss.  No pun intended.  New carb boots are the worst.

[ofreen]

 It doesn’t have to be that difficult.  Use some lubricant when mounting the carbs to the engine.  I use RuGlyde tire mounting lube for this.  I have always been able to push them on by hand using this stuff and it is useful for many other jobs.  Get new carb to airbox rubbers.  They don’t cost that much  and greatly ease the task of mounting the airbox. Plus they will seal.

[Bennie1977]

Im located in oakland county. Kzoo is like a 2 hour drive from me. Might be worth looking into. The boots are brand new on the head side. I boiled them for hours just to  a little flexibility into them. I got them on, i just really don't want to go though the fight again. Hints trying to cut corners and silicone the fuel rail. The boots coming out  the air box is still pretty good, some flexibility, but not to soft. I cant get inside the box to get to the boots even if i wanted to replace them.

[Bennie1977]

Does the nipple on the air box connect to the disk shaped box in the picture? It already has a hose connected to it coming from the head. The nipple on the disk is the same as the air box, and it didnt have anything connected to  it when i had pods on it.

[ekpent]

 Did you get the right manifold boots for your model ? Doesn't seem that they should go on that hard especially when new.

[754]

The trick is to get one outside one in first, then wiggle and push accross the rest.. doing several at once won't work as easily.

[evinrude7]

The trick is to get one outside one in first, then wiggle and push accross the rest.. doing several at once won't work as easily.

+1

[Bennie1977]

I bought aftermarket parts not made by honda, they fit, just very tight. Shoulda spent a few extra bucks and got real parts. Had to make sure they were all perfect or else they wouldn't go on. Any info on the valve on top of the air box?