CB650 Spark Splug Problem PLZ HELP

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WiseTurtle
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CB650 Spark Splug Problem PLZ HELP

Postby WiseTurtle » Tue Mar 27, 2018 8:02 pm

CB650C 1980
4in4 Pipes and K&n filter
Idle screws at 2 1/8 turns out + additional 1/8

I finally got my plugs to run lean for the first time instead of fouling them ($80 of plugs now :cry: ). They were too lean so I gave all the idle screws an additional 1/8 of a turn from stock. Now cylinders 2 &4 (havent removed tank for #3 yet) are fouled again and 1 is still a little lean but better than before.

Here is 1 and 4 for comparison https://www.flickr.com/photos/83017157@N08/27189725248/

All plugs were running lean and were all similar before my 1/8 adjustment when I checked. When I put the idle screws to factory turns I did a carb sync when they were at 2 1/8. Now that I did that adjustment they seem to be out of sync again cause my idle is a bit whacky below 1300rpm where before I could idle for days just fine. Could the carbs have gone out of sync by adjusting the pilot screws and as a result they are getting different levels of fuel now from the uneven vacuum?Everything was fine before this addition turn.

By the time I got to the DMV for my skills test it was running like crap and stumbling through my cone weave making me lose control. Guess I know why now :(

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GeorgeSweety
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Re: CB650 Spark Splug Problem PLZ HELP

Postby GeorgeSweety » Wed Mar 28, 2018 12:11 pm

Hi WT, can you put your mixture screws back to what they were before you did the extra 1/8 turn then take the bike for a run and check the plugs again?

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WiseTurtle
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Re: CB650 Spark Splug Problem PLZ HELP

Postby WiseTurtle » Wed Mar 28, 2018 3:22 pm

Ill try that and post results. It seems like you and I are the only ones that use this site :( Empty now it seems.

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GeorgeSweety
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Re: CB650 Spark Splug Problem PLZ HELP

Postby GeorgeSweety » Wed Mar 28, 2018 3:48 pm

WiseTurtle wrote:Ill try that and post results. It seems like you and I are the only ones that use this site :( Empty now it seems.

I thought it was getting a bit busier TBH, there's been a few new members over the last couple of weeks.

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WiseTurtle
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Re: CB650 Spark Splug Problem PLZ HELP

Postby WiseTurtle » Thu Mar 29, 2018 9:57 pm

I turned the pilot screw backs in 2 1/8 exactly where they were before when the plugs were all lean and there all still fouled except for #1. #1 the base ring got darker but the porcelain part is still white. On #4 the plug has a thin dark vertical sliver along the side with everything else being fouled exactly like before. What the hell is going on? Now the bike still fouling and runs like crap still even though I set everything back to the way it was. The carbs still seemed to be unsynced because its all over the place and still stutters in all rpm range or holding the throttle open, almost feels like the back tire is skipping real fast. At high rpm past 5k it sounds like misses and lugs but I could be wrong. Just wish I could get my money back for everything I spent on this piece of crap :(

Riche
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Re: CB650 Spark Splug Problem PLZ HELP

Postby Riche » Fri Mar 30, 2018 4:27 am

Hi, When you say fouling, what are the plugs being fouled with?
Are you running stock air filter or pods?
Ahh pods sorry just read your original post.
Has it been rejeted ? Main jets etc?

Rich

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GeorgeSweety
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Re: CB650 Spark Splug Problem PLZ HELP

Postby GeorgeSweety » Fri Mar 30, 2018 5:42 am

Riche wrote:Hi, When you say fouling, what are the plugs being fouled with?
Are you running stock air filter or pods?
Ahh pods sorry just read your original post.
Has it been rejeted ? Main jets etc?
Rich


Hi Rich, WT is using the standard airbox with a K&N filter, I'm presuming his jets are standard.
WT, have you removed, cleaned and lubricated your spark advancer mechanism behind your pick up plate on the right hand side of your crank as you sit on the bike? If your bob weights are sticking then it could be throwing your timing out so that your fuel isn't burning in the cylinder correctly. These units are prone to trouble if not lubed regularly, you will need to remove your pick up plate to access the advancer so before you remove it, scribe or mark a line from your pick up plate on to the casting so that when you reassemble it you put your pick up plate back in the same position, the position of your pick up plate is how your timing is set.

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Folsoml
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Re: CB650 Spark Splug Problem PLZ HELP

Postby Folsoml » Fri Mar 30, 2018 8:04 am

WiseTurtle wrote:Ill try that and post results. It seems like you and I are the only ones that use this site :( Empty now it seems.


Sorry. :oops: Been tied up lately.
Have a problem with your CB650? Have a technical question? Click here!


My Current Bikes: 2005 HD FLHTCUI Electra Glide Ultra Classic, 2007 Yamaha Vino,

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GeorgeSweety
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Re: CB650 Spark Splug Problem PLZ HELP

Postby GeorgeSweety » Fri Mar 30, 2018 8:49 am

Folsoml wrote:
WiseTurtle wrote:Ill try that and post results. It seems like you and I are the only ones that use this site :( Empty now it seems.


Sorry. :oops: Been tied up lately.


What you get up to behind closed doors is nothing to do with us :wink: :lol:

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Folsoml
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Re: CB650 Spark Splug Problem PLZ HELP

Postby Folsoml » Fri Mar 30, 2018 11:56 am

GeorgeSweety wrote:
Folsoml wrote:
WiseTurtle wrote:Ill try that and post results. It seems like you and I are the only ones that use this site :( Empty now it seems.


Sorry. :oops: Been tied up lately.


What you get up to behind closed doors is nothing to do with us :wink: :lol:


:lol: :lol: :lol:
Have a problem with your CB650? Have a technical question? Click here!


My Current Bikes: 2005 HD FLHTCUI Electra Glide Ultra Classic, 2007 Yamaha Vino,

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WiseTurtle
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Re: CB650 Spark Splug Problem PLZ HELP

Postby WiseTurtle » Fri Mar 30, 2018 1:01 pm

How do I lube it? Do I just slather the whole thing with oil or grease? I been meaning to check my air gap in there but I dont have the brass feeler gauges but since it ran lean before Im guessing that wasn't it anyway.

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GeorgeSweety
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Re: CB650 Spark Splug Problem PLZ HELP

Postby GeorgeSweety » Sat Mar 31, 2018 2:27 am

WiseTurtle wrote:How do I lube it? Do I just slather the whole thing with oil or grease? I been meaning to check my air gap in there but I dont have the brass feeler gauges but since it ran lean before Im guessing that wasn't it anyway.


You have to take it apart, have a camera at hand to take pictures so you know how it goes back together. The chances are it will have rust on it, give it alight sanding at any contact points and keep checking it for smooth operation. I used high melting point Lithium grease on mine, just a small amount applied by a small brush. To set the gap on your pick up's use a sheet of paper, don't go to heavy when re-tightening the screws as they can easily strip.

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Folsoml
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Re: CB650 Spark Splug Problem PLZ HELP

Postby Folsoml » Sat Mar 31, 2018 9:36 am

Please forgive this question:

Is there not oil in with the advancer on the CB650? I ask this because it's been a long time since I actually WORKED on a CB650. I have much more experience with the DOHC Honda's of that same era (CB900C, CB750C, etc) and there IS oil in the on those models. The oil is mostly for the starter clutch (which is right behind the advancer on those bikes), while the starter clutch on the CB650 is in another location.
Have a problem with your CB650? Have a technical question? Click here!


My Current Bikes: 2005 HD FLHTCUI Electra Glide Ultra Classic, 2007 Yamaha Vino,

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GeorgeSweety
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Re: CB650 Spark Splug Problem PLZ HELP

Postby GeorgeSweety » Sat Mar 31, 2018 9:50 am

Folsoml wrote:Please forgive this question:

Is there not oil in with the advancer on the CB650? I ask this because it's been a long time since I actually WORKED on a CB650. I have much more experience with the DOHC Honda's of that same era (CB900C, CB750C, etc) and there IS oil in the on those models. The oil is mostly for the starter clutch (which is right behind the advancer on those bikes), while the starter clutch on the CB650 is in another location.


No, they are dry, very, very dry, that's why they rust and seize up.

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WiseTurtle
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Re: CB650 Spark Splug Problem PLZ HELP

Postby WiseTurtle » Sat Mar 31, 2018 10:28 am

Bad news. The previous owner seemed to over tighten every damn thing and he did the same with the 3 screws holding the advance plate. It looks like they were way over-tightened and then with the heat got welded in there. I broke 2 of my craftsmen bits trying to get it out and that was after PB nutt buster and WD40 while carefully banging on the heads with a hammer to vibrate them loose like I did with the filter bolt.. End result was I stripped the first screw completely. I ended up just unloading a can of wd40 towards the advancer behind the plate. Then I turned on the bike with the cover still of and at different throttle positions I unloaded the WD40 again and something happened because the bike changed and idled smoother and I was able to accelerate smoothly without that sputtering but still fouled my plugs except for #1. Anything else to look for?


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