Author Topic: Static timing  (Read 2042 times)

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Offline quidger

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Static timing
« on: August 29, 2009, 07:38:09 AM »
I am trying to statically time my '75 CB550 and I am having a hard time getting it running.
I get the light to go on a precisely the right time on # 1-4 but when I try to  line up the F marks on #2-3 they are way off.
Since 1-4 are right on should not the #2-3 also be timed correctly and the light should be going on?
What am I doing wrong?
Thanks.

Offline Johnny5

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Re: Static timing
« Reply #1 on: August 29, 2009, 08:25:21 AM »
You need to slide the base plate for 2-3. Then recheck point gap.
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Offline JohnG

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Re: Static timing
« Reply #2 on: August 29, 2009, 08:26:21 AM »
One set of points is fastened directly to the large plate.  I would time those first.

The other set is mounted on a second, small, plate and can then be adjusted after the first set is done.

In other words, they did provide you with the capability to adjust them independently.
1976 CB750F - original owner
1971 CB450
1979 CB750F
1982 CB900F
1983 CB1123F - Rick Stetson motor

Offline quidger

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Re: Static timing
« Reply #3 on: August 29, 2009, 10:42:12 AM »
I got the points adjusted statically and they seem to be lined up properly. On the adjustment for the #2-3 points I had to turn the adjuster plate as far as it would go in one direction to get it to line up with the F mark. And on the #1-4 points I moved the adjuster plate just a bit off of center to get it to line up with the F mark. Does that seem unusual?

Still can't get the bike to start. Had the carbs off last week and cleaned them up. The bike started after that and now no cigar with starting. New spark plugs that were blackened a bit with carbon after the bike started last week. I cleaned them up.

So I have clean carbs, new spark plugs, and the bike is now timed. I checked for spark at both the plugs and the points and all is well. I checked to make sure that the float bowls have fuel. And she still won't start. Kind of a mystery since it started last weekend.

I gave the bike some throttle while I was trying to start it and it bogged down the cranking considerably. Is that significant?

Any suggestions are appreciated.

« Last Edit: August 29, 2009, 12:42:17 PM by quidger »

Offline JohnG

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Re: Static timing
« Reply #4 on: August 29, 2009, 02:47:56 PM »
On the points:

a) what gap do you have?

b) could you take a business card and run it in between them??  Kind of a quick polishing job.

c) are they new?
1976 CB750F - original owner
1971 CB450
1979 CB750F
1982 CB900F
1983 CB1123F - Rick Stetson motor

Offline quidger

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Re: Static timing
« Reply #5 on: August 29, 2009, 03:09:38 PM »
Points and condensers are both new OEM TEC. Gapped at approximately .04 mm. I took a piece of heavy stock paper and dragged it through to clean off any factory residue.

Offline JohnG

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Re: Static timing
« Reply #6 on: August 29, 2009, 03:58:37 PM »
You did not say how the bike was running prior to the new points and work...

Some thoughts:

* check the plug caps with a multimeter.  They do fail.  In any event, you can cross them off your list or deal with them.

* if the bike has been sitting then a number of areas can be a problem
    -  gas went south
    -  jets clogged
    -  mice built nests in the airbox
    -  "                             " exhaust
* in the  end every motor needs  fuel, spark and compression
* hook a car battery up as a jumper even if your bike battery is ok. The extra voltage and faster spinning might get you going

*squirt some lacquer thinner in one or two  plug holes
1976 CB750F - original owner
1971 CB450
1979 CB750F
1982 CB900F
1983 CB1123F - Rick Stetson motor

Offline quidger

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Re: Static timing
« Reply #7 on: August 29, 2009, 05:04:48 PM »
I checked the plug caps by putting screw driver into plug cap and cranked the engine...good strong spark against the cylinder head.
Gas is a few weeks old.
The jets should not be clogged because I cleaned all the jets and checked the floats a week ago. Tank was de-rusted a month ago.
After I cleaned the carbs a week ago and put the new points and plugs in, the bike started and ran. It was not runnig perfectly but the only issue of any consequence was that I was getting an exhaust backfire on #4.
I got a timing light and was going to time the bike and now I cannot get it started.
I hate ti take the carbs off again but maybe that is the next step.
What about trying to adjust the air screws? When I had it running last week, if anything it seems it might be rich (?) too much gas & not enough air in the mixture.
Could that be something worth trying.
By the way this is a 1975 CB550K1.
Thanks.

Offline JohnG

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Re: Static timing
« Reply #8 on: August 29, 2009, 06:38:22 PM »
First rule of old vehicles:  take nothing for granted.I would want to take one of the float bowls off and see what I found.  Enough gas?  rust? anthing else??

Did you set the floats when you had the carbs off?  Did you just clean jets or did you dismantle them further??

Have you checked the compression??

Any chance the advance mechanism is stuck somewhere advanced??  They can get rusty and stuck...

Are the carbs back in the intake boots  (to the head) all the way???
« Last Edit: August 29, 2009, 06:42:03 PM by JohnG »
1976 CB750F - original owner
1971 CB450
1979 CB750F
1982 CB900F
1983 CB1123F - Rick Stetson motor

Offline Roach Carver

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Re: Static timing
« Reply #9 on: August 29, 2009, 06:49:32 PM »
what size main jets?

Offline quidger

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Re: Static timing
« Reply #10 on: August 29, 2009, 07:36:15 PM »
I'm sure that I did a thorough job cleaning the carburetors. I took out the slow jet, main jet and airscrew and soaked and cleaned. Bench synced also.They actually were in very good shape and did not require a ton of cleaning. All of the little holes very perfectly open. I do not have a float measuring device so I measured  from the lip of the carb using a small mm ruler. The accuracy should be as reliable as it could be without having the proper tool. The couplers are totally seated into the airbox and the air cleaner is in place, albeit it may need replacing due to age.
I have not checked the compression. I do not have a gauge and have been looking for an inexpensive one. HF had one but it would not fit a 12mm plug so I'm still looking.
I'm not sure what you mean when you ask about the advanced mechanism possibly being stuck or rusty. IF you mean the mecnhanism behind the plate that the points are mounted on, I took it off and hit it with some steel wool and oiled it up and shot with a little WD-40. Please elaborate if it is something other,
I'm fairly certain that the main jets are stock for what ever came with the bike.
I have a sense that the issue is probably fuel system related.
But I did have a heck of a time getting the static timing correct, so I finally took out the plug for #1 & then #2 and hooked them back into the plug wires and listened and watched for the spark to occur when I turned to the F mark. I think I have it fairly well statically time now.
Thanks for the suggestions, any other input is good.
« Last Edit: August 30, 2009, 06:44:41 AM by quidger »