Author Topic: My buddy asked me to get his bike running.  (Read 10434 times)

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Offline thrutheframe

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My buddy asked me to get his bike running.
« Reply #50 on: July 12, 2012, 09:32:04 AM »
So on Tuesday I fired up the bike for the first time since before the valve adjustment.  It was a complete mess, no idle but ran with the choke on.  It would intermittently hang up at high throttle and generally act like a b#*ch.
  I took the tank off and checked all of my boots and clamps.  All that stuff is new and it was all sealed up nicely.  I ended up pulling the carb bank off thinking I needed to re-clean my idle circuits.  When I was getting ready to pulI the choke spring off I discovered that the vacuum cross over T was off of the #3 carb.  I had to fight it to get it in there without breaking the bank apart.  It fired right up after I got it back together.  It idles well and takes throttle correctly.  The carbs need sync'd and the clutch needs adjusted.  He wants me to swap out his stock mufflers for  MAC, it's pretty quiet and he wants to make it a little louder.  I'm not going to swap out the exhaust until I like how its running. 
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline 70CB750

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Re: My buddy asked me to get his bike running.
« Reply #51 on: July 12, 2012, 10:18:41 AM »
Well done, old chap!
Prokop
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Offline Magpie

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Re: My buddy asked me to get his bike running.
« Reply #52 on: July 12, 2012, 11:34:30 AM »
Good work! Mac 4 to 2 sound good on these bikes. The stock exhaust is quite quiet imo. Cliff.
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Offline thrutheframe

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My buddy asked me to get his bike running.
« Reply #53 on: July 12, 2012, 11:55:24 AM »
http://www.youtube.com/watch?v=SFLvqus28j8&feature=youtube_gdata_player

Thanks fellas.  Amazingly it sounds a lot like Cliff's bike.
« Last Edit: July 12, 2012, 12:02:36 PM by thrutheframe »
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Magpie

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Re: My buddy asked me to get his bike running.
« Reply #54 on: July 12, 2012, 05:07:20 PM »
I kind of like the looks of the stock system better, they are just a bit longet than my Mac system. I couldn't find a good stock set for sale at the time.  Nicely done for your friend. He has a good looking bike there. It's interesting how cheap these bikes seem, even a well turned out 1100F seems to be under $3000.  The 1100F has been called one of the first real superbikes, besides our SOHC4's of course. Cliff.

Offline thrutheframe

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My buddy asked me to get his bike running.
« Reply #55 on: July 17, 2012, 04:06:30 PM »
New tools rock.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Magpie

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Re: My buddy asked me to get his bike running.
« Reply #56 on: July 17, 2012, 04:53:31 PM »
That's porn!  ;D

Offline thrutheframe

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My buddy asked me to get his bike running.
« Reply #57 on: August 03, 2012, 11:21:22 AM »
Im happy to say its all dialed in.  I synced the carbs and rode it up here for lunch.  Smooth as silk!  Handles well at slow speeds, accelerates off idle well and at roll on.  I'm going to send her back to Jeremy and let him ride it for a few days while I'm on Europe.  Them when I come back I'll swap the mufflers out for him.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline thrutheframe

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Re: My buddy asked me to get his bike running.
« Reply #58 on: August 04, 2012, 05:15:14 AM »
$50.00 donated to the cause.  Thanks to Cliff for the info and support.  This project was alot of fun despite some serious frustrations.  The bike rides so nice and smooth and idles like a milk fat kitten.
« Last Edit: September 09, 2012, 04:19:27 PM by thrutheframe »
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline thrutheframe

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Re: My buddy asked me to get his bike running.
« Reply #59 on: August 07, 2012, 06:45:59 PM »
I got this email today from the owner of the Super Sport:

"Dude I got to do a little bit of riding yesterday, you kick ass!  The bike is totally different and I mean totally different.  It is so smooth, silky smooth.  The only 2 issues that I had were; it took close to 5 mins to start and the other one was after it has really warmed up, it idles at about 2400 rpm.  The idle seems a little high, but that is more of a nit pick thing.  Not sure what the issue with it taking forever to start is.  I wasn't sure if it was close to being out of gas so I turned the gas knob to reserve and pulled the choke all the way out and let it sit for a minute and just kept cranking it.  A couple of times the starter seemed like it would slip.  Those two things are the only 2 that I could tell.  I'll be at work till, august 15th.  Once again thanks so much for working on my bike.

Jeremy"


When I get back home I'll sort out his tought to start issue and the idle free of charge.  Im pretty proud that he is so happy with the results.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Magpie

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Re: My buddy asked me to get his bike running.
« Reply #60 on: August 07, 2012, 07:16:19 PM »
I found if I give the throttle a couple of turns before hitting the starter button, it fires up better. The battery must have a full charge. And, yes once it warms up the idle goes up. I usually just turn it down a bit with the large black knob under the carbs, it seems to like about 1200 rpm. I get some clutch rattle.

Offline thrutheframe

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My buddy asked me to get his bike running.
« Reply #61 on: September 09, 2012, 04:13:23 PM »
I'm convinced that the accelerator pump circuits aren't quite right yet.  Dude brought it back to me to have the exhaust swapped out and a starter relay issue sorted out.  The thing takes forever to get started if it has been sitting longer than overnight.  I think I mentioned before that I'm going to get an OEM accelerator pump and swap it out for the aftermarket part I bought.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Magpie

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Re: My buddy asked me to get his bike running.
« Reply #62 on: September 09, 2012, 05:05:38 PM »
How was the diaphram on the accelerater pump? Did you clean out the passages on the check valve on the top on page 20 in the carb manual you downloaded from the 750 customs site.
"Also, the float bowl has a check-valve that needs to be cleared. Spraying into this hole should result in a jet of spray out each of the 4 sides of the square brass insert. You may have to soak the bowl further if this check-valve is clogged" It took me a long time to get that cleaned. How are the o-rings on the tubes connecting the carbs?                                                                                                                       '
Cliff.

Offline thrutheframe

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My buddy asked me to get his bike running.
« Reply #63 on: September 12, 2012, 08:23:23 AM »
I replaced the pump diaphragm.  I think that's the problem.  The part I got from Sirius didn't really fit in there as nicely as the original.  The pump works but it never seemed to pump alot.  I ordered an OEM diaphragm. The starter is a little funky and he wants me to pull it out and go through it so it's not like either of us has to eat the time for pulling the carbs again.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline thrutheframe

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Re: My buddy asked me to get his bike running.
« Reply #64 on: September 26, 2012, 12:19:49 PM »
  My life is just too busy to keep up with posts here the way that I would like.  I dont see how people with kids do it.  Cliff you quoted the carb cleaning manual .... "Also, the float bowl has a check-valve that needs to be cleared. Spraying into this hole should result in a jet of spray out each of the 4 sides of the square brass insert. You may have to soak the bowl further if this check-valve is clogged"  Interestingly enough, when you buy the OEM diaphragm kit it comes with a new cap for the Accel pump.
  I put the OEM diaphragm in and the bike fired right up.  I made sure that I installed the new parts on Tuesday and I didnt even look at the bike until Sunday, I wanted to prove my theory that the accel pump was the issue.  I tried to install the Mac 4 into 2 exhaust but of course the thing comes from Mac with no clamps.  The provide new copper crush washers and new collars but no clamps???????  I put the head pipes on and ordered the correct clamps.
  This bike is like one of my own but at this point I really need to get it sorted out and away from my shop so I can get my own bikes sorted out.  Cliff I really appreciate your help and support.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Magpie

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Re: My buddy asked me to get his bike running.
« Reply #65 on: September 26, 2012, 06:42:18 PM »
You're very welcome!  :D Cliff.

Offline thrutheframe

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My buddy asked me to get his bike running.
« Reply #66 on: October 25, 2012, 05:53:01 AM »
  I've had this bike just sitting in my shop while I have been out on the road working. I'm really glad Jeremy is a patient guy.  Last night I put the clamps on and wasn't expecting it to fire right up I'm my shop but once it was all together I hit the starter button and the thing fired right up.  Buying that OEM accel pump kit was a huge help. Unfortunately I have to go back out of town today and I won't get back til Sunday.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Xnavylfr

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Re: My buddy asked me to get his bike running.
« Reply #67 on: November 18, 2012, 05:49:16 AM »
Very good info to follow, ONE thing to mention , when you change to the MAC less restrictive exhaust you may have to go back in the carbs and do some jetting..

Always remember"" anytime you allow more air out (EXHAUST) you engine wants to pull more air in (CARB INTAKE) Less restrictive exhaust systems will cause the engine to run lean and you'll need to adjust for that!!


Xnavylfr(CHUCK)

Offline thrutheframe

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Re: My buddy asked me to get his bike running.
« Reply #68 on: November 18, 2012, 07:09:02 AM »
  Chuck thanks for checking out my project.  Your reference to the leaner condition caused by the MAC exhaust is one of the things I discussed with him early on.  He has the bike right now but we plan to get together next week and pull his plugs and take a quick look.  I imagine these bikes were pretty lean when they were brand new.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT