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Author Topic: Press-in jet '77 750F2 (PD carbs)  (Read 1322 times)

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Offline afastman

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Press-in jet '77 750F2 (PD carbs)
« on: July 20, 2010, 02:17:33 PM »
I fouled a plug the other day in cylinder #1.  changed out the plug...no help.  dropped the carb bowl and what did i see floating in the gasoline?  Yup, the press in jet.  So i placed it back in its proper orifice and gave it a whack with the side of my pliers, buttoned it up and voila, bike ran better than it ever has...for about 5 minutes until the jet vibrated back out. 

HOW o HOW do i get this guy to stay put?  I am at my wits end.  i have dropped and reinstalled the bowl so many times i am concerned about stripping the bloody screws on the carb boy that hold the bowl in.

thanks
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Offline afastman

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #1 on: July 21, 2010, 08:17:01 AM »
bump
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Offline voxonda

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #2 on: July 21, 2010, 08:28:06 AM »
It's a press fit, so if it comes loose you have to be creative, gently tap on the 'oriface' to slightly 'mess-up' the entrance of the hole. And/or get a plier to roughen up the side oriface of the jet and then tap it in. Should do the trick. But do not 'overdo' it.
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Offline afastman

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #3 on: July 21, 2010, 08:30:22 AM »
file that in the "gentle brute force" category?

Anyone have luck with teflon tape, silicone caulk, jb weld?  I hate to bugger up a perfectly (otherwise) serviceable set of carbs.  But I will attest riding on 3 cylinders is not day at the beach.
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Offline Bamboozler

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #4 on: July 21, 2010, 09:16:44 AM »
I found myself in this same situation when I installed new jets.  All was well with pressing in the new jets, they fit snug.  But when trying to going back the stock jet they (the stock jets) would slide in and out without any resistance. 

Voxonda makes good sense to get them to fit and stay put.  If you are still struggling you may also find a solution with new jets, as they seem to be slightly larger.

(the new jets I'm referencing came from www.siriusconinc.com, I don't know exactly who manufactures them)
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Offline afastman

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #5 on: July 21, 2010, 09:21:54 AM »
Thanx for the link.  Gentlemen (and ladies out there too), I think we officially need to add several hours to daylight savings time to accomodate the "waiting" for solutions to arrive in the mail. 
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Offline jtb

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #6 on: July 21, 2010, 06:21:26 PM »
I'll pull one out of an old carb body for you if you want.  Don't know that it won't do the same thing.
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Offline BobbyR

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #7 on: July 21, 2010, 06:31:40 PM »
They usually fit really tight, but you may be the lucky one. You could try to expand the bottoms a bit just to return that  friction fit. Be gentle!
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Offline TwoTired

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #8 on: July 21, 2010, 09:52:19 PM »
Use loctite Red 271, or epoxy them in place.
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Offline afastman

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #9 on: July 22, 2010, 08:08:12 AM »
temporary fix of 2 wraps of teflon tape lasted me a 30 mile ride yesterday.  Now to drill out and retap the 4mm holes in the bodies to hold on the bowls.  It is never ending.
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Offline BobbyR

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #10 on: July 22, 2010, 09:11:42 AM »
Quote from: afastman on July 22, 2010, 08:08:12 AM
temporary fix of 2 wraps of teflon tape lasted me a 30 mile ride yesterday.  Now to drill out and retap the 4mm holes in the bodies to hold on the bowls.  It is never ending.
Rather than re tap holes, a lot of people just use a nut on the existing bolt.
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Dedicated to Sgt. Howard Bruckner 1950 - 1969. KIA LONG KHANH.

But we were boys, and boys will be boys, and so they will. To us, everything was dangerous, but what of that? Had we not been made to live forever?

Offline afastman

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #11 on: July 22, 2010, 09:16:16 AM »
I only have 1 of 3 holes on each that daylights.  the stock crews do not come near to passing through the other side.  The other 2 holes on each are blind.  Unless the insinuation is to drill through the other side of those blind holes.  I am not sure there is enough meat to perch a nut on top of anyway
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Offline BobbyR

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #12 on: July 22, 2010, 09:56:32 AM »
Quote from: afastman on July 22, 2010, 09:16:16 AM
I only have 1 of 3 holes on each that daylights.  the stock crews do not come near to passing through the other side.  The other 2 holes on each are blind.  Unless the insinuation is to drill through the other side of those blind holes.  I am not sure there is enough meat to perch a nut on top of anyway
Sorry, I hope u have a steady hand. Hope it works out well.
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Dedicated to Sgt. Howard Bruckner 1950 - 1969. KIA LONG KHANH.

But we were boys, and boys will be boys, and so they will. To us, everything was dangerous, but what of that? Had we not been made to live forever?

Offline afastman

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #13 on: July 22, 2010, 10:01:36 AM »
ever see blazing saddles...fade to the scene...

<object width="480" height="385"><param name="movie" value=" name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src=" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>
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Offline voxonda

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #14 on: July 22, 2010, 10:25:13 AM »
Nothing to do with (gentle) brute force,  if you know how. Have done it to two F2's and a K7. All three never had any problems afterwards. :)

Rob
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Offline Bamboozler

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #15 on: July 22, 2010, 12:59:21 PM »
Quote from: afastman on July 22, 2010, 08:08:12 AM
Now to drill out and retap the 4mm holes in the bodies to hold on the bowls.  It is never ending.

You're not alone! This little fowl plague has hit me more than a few times when making jet changes... Nothing more annoying that getting the whole works rejetted and tightening the last screws on the last bowl and one of the screws gives way.. :( Off to the drill press/tap/over sized screws we go..  I think I've replaced more than half my screws so far, should probably just do em all and get it over with. :)
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'78 CB750F Turbo, 101 rwhp @ 8 PSI (Project thread)
2007 Yamaha FZ1
'78 CB750F basket case crying for a resto
'78 XL250S
'78 Suk GS750E
Digital Ignition project (Project thread)

Offline afastman

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Re: Press-in jet '77 750F2 (PD carbs)
« Reply #16 on: July 22, 2010, 01:15:09 PM »
progress??? right??
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creul, nasty, neurotic, paranoid, antisocial...but basically happy
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