Topic: Introduction and an issue (of 2-3 type)

[theclaw]

Gents (Ladies too),

I'm mostly a Ducati guy but I talked my son into a '78 CB550 for his first bike. Very clean, new wiring loom, fresh rubber, carbs rebuilt and gone through. SUPER clean.  Except we have an issue.  Cyl 2-3 are "weak". By weak I mean, they run but the pipes do not get that hot. Like 1/2 get super hot but 2/3 you can still touch them after warm up. They are not cold like 2/3 are not firing but something is wrong.

Some checks we've already made:
Ohm check on the coils looked ok,
They are getting spark and gas
Static timing is set however the 1-2 timing is all the way to one side.

I notice something while looking for loose wires, the main connector to the fuse box gets pretty hot.

https://drive.google.com/open?id=1laVVDlkn3rp8YYB24ChnfuFcf3kM-EpN

https://drive.google.com/open?id=1v5PBjhu7CFct4gxQ3XxWRsP_yVJpZhlp

Dont know if that's related or not.

Still we can't chase down why 2/3 just not running right. Suggestions?

Thank you,
Jeff

[Mr. Mike]

Jeff,
Im no expert, but here are a few things to check. Based on your description of the fuse block getting hot, it’s a good practice to remove all fuses and thoroughly clean/polish each fuse holder, after all, the 550 is what, 40 years old? New fuses at this point aren’t a bad idea either.

Next, check to be sure the main frame ground is solid as well as checking each bullet connector for good seating and continuity.
If you have a wet battery (lead acid), check the water level.

Pitted or dirty points for cylinders 1/4 and 2/3 should also not only be cleaned, but timing should be checked if you suspect ignition type troubles. You can swap coils and see if the trouble moves to the other two pipes 1/4. New plugs too are a good idea.



There is plenty of good information as well as video on YouTube or a simple google search of you model. This site too has information on your model regarding tune up, trouble shooting,  etc.
Look under “Manuals and Technical Documents”. There should be enough information to get you going to narrow your trouble down, if not find it and remedy it.

Oh, and welcome to the forum!

[1976cb750f836]

Compression?

[Jerry Rxman Griffin aka MuthaF'er]

carbs synched?

[theclaw]

Follow up:
Jerry: They should be, they were just gone thru by Acme in Chicago
'76CB: I will check the compression. We have a little sooty ring around the cylinders and I'm afraid to ask why that's there 
Mr Mike:Pretty sure ground is good. I'm getting a ground connection on a number of spots on the bike. Also, Acme put in a new wiring loom before we bought it. Battery is new and levels are good. It's the fuse block that's getting hot but the big connector that comes into/goes out of it. Points have been recently scuffed up. timing is a little issue though. We have to spin the 1/2 disk all the way over to get the test light to light when the flywheel is on the mark. (taking into account I have had ECI for a loooong time and it was my '79 KZ650 when I last worked on a set of points).  Yes, we've been searching away, here and googling. Always feel some good dialog on the forums is priceless than a random search.

thanks for all the advice so far!

Jeff

[seanbarney41]

First of all, one set of points triggers cylinders 1 and 4, other set triggers 2 and 3.  If you can touch your pipes after 30 seconds run time, those cylinders are NOT firing.  I have not heard of many shops taking the time to do these bikes right, so the shop that did the work very well could have missed lots in the carbs and electrical. 

Problems with 2 and 3 generally indicates ignition.  I would start by double checking points gap and timing.  If that doesnt get 2 and 3 going, swap the condensor from 1 and 4, and see what happens.

[jgger]

Check your points and condensers to see if the are DIE-hachi (dihachi I think it is spelled). The stuff you want is Tek.

[seanbarney41]

Daiichi

[theclaw]

Another thing that looks a little off is when setting static points I have to move the wheel all that over to one side and even then, it barely connects and lights the test light. Could the pickups on the points be worn?  Guessing yes.

I'd post a picture but haven't learned how to do that yet and did not see instructions in the FAQ. Everytime I try and insert a link from my Google drive or Dropbox it doesn't show up right.

https://www.dropbox.com/preview/CB550/cb550/20190727_201151.jpg?role=personal

[Bankerdanny]

Another thing that looks a little off is when setting static points I have to move the wheel all that over to one side and even then, it barely connects and lights the test light. Could the pickups on the points be worn?  Guessing yes.

I had this issue with my last 550, and I know that it isn't unusual. You can compensate to some extent by adjusting the points gap.

[evinrude7]

Another thing that looks a little off is when setting static points I have to move the wheel all that over to one side and even then, it barely connects and lights the test light. Could the pickups on the points be worn?  Guessing yes.

I had this issue with my last 550, and I know that it isn't unusual. You can compensate to some extent by adjusting the points gap.

could the problem that jeff is having be remedied with a shim(s) at the boss(es) of the case where the points plate lays to reduce "gyroscopic" movement.  not sure "gyroscopic" is the word but you know what i mean. 

[HondaMan]

Another thing that looks a little off is when setting static points I have to move the wheel all that over to one side and even then, it barely connects and lights the test light. Could the pickups on the points be worn?  Guessing yes.

I'd post a picture but haven't learned how to do that yet and did not see instructions in the FAQ. Everytime I try and insert a link from my Google drive or Dropbox it doesn't show up right.

https://www.dropbox.com/preview/CB550/cb550/20190727_201151.jpg?role=personal

This is the classic Daiichi problem. It is caused by their incorrect points geometry, which causes one set of points to be way out of spec, and the other is impossible to time up. While the real fix is to get a new TEC or Hitachi points plate assembly from Honda (South Sound Honda, about $80), there are some temporary things you can do that will help a little.

The first is: slightly bend the ground arms on the points sets toward from the moving arm. while this will make the points' faces non-parallel, it will let you set the gaps to be the same on both sides. Bend them about 0.004" toward the moving contact, then re-time everything. If the timing will not even come close, then re-bend them the other way, 0.004" away from the moving contact, then re-time. The quick way to try this out is to do it with only the "L" (1-4) points, and set them at 0.014" gap on the top of the points cam, then find out where they are opening. If too soon, then bend the ground arm toward the moving arm, set the gap and try again: you want the top screw in the points plate to be near center when the points open at the "F" mark for the 1-4 side. The reverse is also true: if at 0.014" gap the points open too late, then bend the ground arm away from the moving arm, etc.

In the end: to test my Transistor Ignition under the worst-case scenario I could create, I used a set of Daiichi points on a Daiichi plate with the ground arms bent so far that the moving contacts were only touching on their edges, for 6 years of riding.  At the end, the non-moving arms' contacts showed a little 'smile' where the edge of the moving contact had been pounding on them, but they still held time and still worked OK. If used without this Ignition box, though, they will wear (burn) quickly in that scenario, so the timing will shift sooner than normal, retarding itself probably within a few thousand miles.

[theclaw]

Swapped the condensers and we got 2/3 to fire, but 1/4 were cold.   so we got one problem solved!!

We will be ordering new condensers and while we are at an upgraded points plate.

Lots of good info, thank you. Stay tuned!

Jeff

[Duke McDukiedook]

To save on points wear when you get some spare cash you might want to look into Hondaman's transistor ignition, it will help with reducing points wear.