head leaks and shifter seal

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my79650
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Re: head leaks and shifter seal

Postby my79650 » Thu May 17, 2012 7:45 pm

If i can get the plastic from the rest of the old switch out of the hole(guts pulled out of the assembly) i was thinking of using a small file to cut out the remainder of the screw; then replace the switch and use a strong adhesive glue to hold it in place. the lever doesn't make that much pressure on the switch itself to knock it back out of the hole in the m/c mounts. Or i can just say screw it and rebuild my spare 79 m/c. Or rethread the cover holes on the m/c i picked up a few weeks ago; the one i had in the "sweet deals" thread.

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Volker_P
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Re: head leaks and shifter seal

Postby Volker_P » Fri May 18, 2012 6:04 am

If you file it down, just file it that much that you can insert the new switch with a bit of force. Then cement a piece of paper (or whatever fits in there) into the gap between switch and bore opposite to the filed bolt.
Guess this will fix it forever. :wink:
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my79650
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Re: head leaks and shifter seal

Postby my79650 » Fri May 18, 2012 5:09 pm

I will give it a go with the file. Now my other little problem since the o ring replacement: starts fine; idles fine when warmed up in yard, works fine out on the road, but when i gear down and stop it quits. Little twist of the throttle and it starts right up. Sometimes it idles up and down a bit then levels out. Been doing this for two days now. When that happens it acts like it runs out of gas. New inline filter and replacement line. No gas leaks and no vacuum leaks on either side of the carbs. Tapped each carburetor with a screwdriver in case the floats are sticking. All i did was remove them and set aside in a clean garbage bag until i installed them after i got the head back on. I adjusted both cables in case they were off a little and no change then either. Any ideas as i don't have kits on hand for these as i really don't want to tear those carbs apart. I did the leak test with a small propane torch minus the flame.

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Volker_P
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Re: head leaks and shifter seal

Postby Volker_P » Sat May 19, 2012 3:44 am

Sounds like it does not run permanently on all four.
Might be poor carb synchronization or just old spark plugs or some other little tricky issue.
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

my79650
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Re: head leaks and shifter seal

Postby my79650 » Sat May 19, 2012 4:46 am

I will change the plugs again; may as well check the valve clearances again too; just in case i am still off after the tear down and rebuild. I admit it is a small annoying thing that i missed; just haven't figured it out yet. Positive i got the timing right as the easy starting and good power on the road; but since i am checking everything i may as well pull the cover and re-check that too. No sense in doing just some of the confirmation checks.

my79650
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Re: head leaks and shifter seal

Postby my79650 » Sun May 20, 2012 10:43 am

I changed the plugs; and checked the valves; #3 exhaust was off a little; reset it. Rest were fine. Had to take the m/c off the bike to get the rest of the old brake light switch casing out out of the hole. Grabbed a dremmel stone that fit the drill and ground it down a little then i tapped the new switch in place. It won't move out of place, was a very tight fit, no need for glue. Need to go for a drive to see if the plugs was causing it to stall out, after i install the m/c and bleed it out. Will post results after i go for a drive to see if the plugs was the problem.

my79650
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Re: head leaks and shifter seal

Postby my79650 » Sun May 20, 2012 12:52 pm

Damn thing still stalls out when stopping. I keep messing with the idle screw to have some sort of idle. Then when i do stop its revving nearly 2k rpm. I am going to change coils in case they're breaking down when hot before i pull the carburetors off. Never had this stalling problem before. If that don't help it then i tear down the carbs!

my79650
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Re: head leaks and shifter seal

Postby my79650 » Mon May 21, 2012 5:45 am

Just to point out: stock carbs and engine. No modifications to engine or carburetors. These carbs were recently on my 1st 79 cb650. Currently on my 2 yr old cb650, well; 2yrs old to me since i bought it. I never had the carburetors apart except for separating #1 to replace the fuel line o rings. I got it down to a few things for the stalling issue: 1; dirty carbs(don't know if they ever was cleaned before), 2; coils/wires shorting out after reaching operating temp(fine on open road no missing slight hesitation on hills) , 3; air flow: filter may look good but not(swap filter or add a washer to cover to increase gap for air flow). No filter is too lean; so try toying with it.....trying to avoid breaking down the pd50s....4; head gasket NFG: letting it lose some compression and quit when stopping at lights, stop signs etc. This only happens after being driven for 5 to ten minutes. Btw, no functional choke system, plastic cable hookup broke;, removed the butterfly plates and screws, accelerator pump is fine; twist throttle 6/7times for first start of the day and it fires up. Have to stay with it as the nature of the beast need to babysat. Any other ideas bout this stalling issue?

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Volker_P
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Re: head leaks and shifter seal

Postby Volker_P » Mon May 21, 2012 6:10 am

my79650 wrote:I never had the carburetors apart except for separating #1 to replace the fuel line o rings.
Enough to loose synchronization. It should not die at 2000. If everything is more or less set all right at laest 1200-1300 should be possible without problems.
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

my79650
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Joined: Tue Apr 06, 2010 11:37 am
Location: Gagetown, New Brunswick Canada

Re: head leaks and shifter seal

Postby my79650 » Mon May 21, 2012 7:46 am

All i did was undo the screw on top to separate them for the o rings. That was almost a month ago and i "never" had any stalling issues until after i had the head off for the o ring swap due to leaking. I also never touched any of the other screws on the carburetors....like i said; no stalling issues until "after the head was removed and reinstalled". So after talking to a good local mechanic; i have to pull the covers off and check the cam timing; he said it may be off 1 tooth; causing it to stall in traffic; stop signs etc. Be back later!

my79650
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Re: head leaks and shifter seal

Postby my79650 » Mon May 21, 2012 9:19 am

My own fault for being in a hurry....got my timing off a few teeth; sorry for venting on here Volker, got a few pics of what i found
Attachments
cb650 timing 001.jpg
Camshaft timing set at mark
cb650 timing 001.jpg (13.34 KiB) Viewed 7021 times
cb650 timing 002.jpg
crankshaft marks off some when i set the camshaft timing up to #1 tdc
cb650 timing 002.jpg (13 KiB) Viewed 7021 times

my79650
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Re: head leaks and shifter seal

Postby my79650 » Mon May 21, 2012 9:24 am

Got to get decent camera; cellphone photos don't really get it done sometime. Anyhow i set it to #1 tdc on the crank. Didn't seem right at the top. That's when i decided to set the camshaft to mark for #1. Then i saw the difference at the crankshaft. According to the photos (despite the clarity) i got it off a few teeth. Basically i had it too slow; making it stall out when there was nothing wrong with the carburetors, or plugs, wires, or anything else on the beast. Time to reset it. Results later.

my79650
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Joined: Tue Apr 06, 2010 11:37 am
Location: Gagetown, New Brunswick Canada

Re: head leaks and shifter seal

Postby my79650 » Mon May 21, 2012 10:55 am

Timing fixed; ran good on my test run. Only stalled once as i had to stop quick; idiot cage pulled out of a driveway. Now to order a set of bearings for the triple tree; then front end will be done.


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