Author Topic: 75 CB550F SS Dies after 10 min but starts right back up!?!? Battery is fine!  (Read 2852 times)

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Offline CarbasaurusRex

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Hi guys,

This is my final attempt at trying to fix this damned Cb550. Long story short the bike will die after riding about 10-15 min. It will start right back up when revving the throttle and then in less than 30 sec it will sputter, pop and ultimately die again. I had to ride home basically revving the whole time because if I would let it idle, IT WOULD DIE. One time I waited about 10 min for it to cool down and it ran and idled fine, but then starting popping and then DYING AGAIN! Not to mention, as I said, it pops like crazy almost sounding like it’s running out of fuel but I have a full tank.

Anyone have an idea on what it could be??

Things that I’ve checked:
-It’s not the fuel tank(dies even on an auxiliary fuel
tank)
- it’s not fuel starvation because there’s no “WHOOSH” sound when I open the fuel cap
- sparkplugs are sparkin blue
- stock air box and jets(needle clips in the middle)
- adjusted timing
- adjusted valves (.003 & .002)
- cleaned carbs three times(not one spec of gunk)
- moving petcock from ON to RES doesn’t help the issue
- when emptying float bowls none of them are dry, so they all have fuel.


Things that I’ve replaced:
- oil and oil filter
- new battery (I haven’t had to charge it for a week and it still turns on and turns starter motor over strong so it couldn’t be the battery dying)
- 4into1 Brand coils, wires and plug caps, spark plugs, condensers, points.
- new petcock (No there isn’t an inline fuel filter)
- OEM Honda genuine fuel lines(no they are not kinked)



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Offline Maraakate

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Did the problem always exist or did it happen after you put the aftermarket ignition components on it?  New condensors are apparently #$%*ty and when the bike gets up to operating temperature they can cut the spark off and it wont start again until after the bike cools down a little bit.

Other things to consider are the fuses.  Check that fuse box.  Might be some corrosion.  Are the fuses hot to the touch?  Could be the corrosion creating resistance then after some voltage is applied through it it opens up.  However, that would be the main fuse so the electronics would be going out if that was the case.

You check the spark plugs for a nice fat spark after the bike will not start?
1977 CB550K
1979 CM400A

Offline CarbasaurusRex

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Did the problem always exist or did it happen after you put the aftermarket ignition components on it?  New condensors are apparently #$%*ty and when the bike gets up to operating temperature they can cut the spark off and it wont start again until after the bike cools down a little bit.

Other things to consider are the fuses.  Check that fuse box.  Might be some corrosion.  Are the fuses hot to the touch?  Could be the corrosion creating resistance then after some voltage is applied through it it opens up.  However, that would be the main fuse so the electronics would be going out if that was the case.

You check the spark plugs for a nice fat spark after the bike will not start?
I bought the bike not running and it’s been like this ever since I got it running. I understand the bike cooling down could relieve some of the issues, but it’s able to start right bike up after it dies with some throttle play. Mind you it’s still hot at this point and wouldn’t really cool down in less than 5 seconds lol
Again this would apply to the fuses and the spark... the fact that it starts right back up with alitte to no effort is what strikes me. What do ya think Maraakate?


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Offline Maraakate

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Did you save the original electronics, i.e. the points plate, coils, etc?  If yes, put those on it and take it for a ride.
1977 CB550K
1979 CM400A

Offline CarbasaurusRex

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Did you save the original electronics, i.e. the points plate, coils, etc?  If yes, put those on it and take it for a ride.
I will try that. If that doesn’t work, what would you suspect?


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Offline Maraakate

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Did you save the original electronics, i.e. the points plate, coils, etc?  If yes, put those on it and take it for a ride.
I will try that. If that doesn’t work, what would you suspect?


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* Vent in gas cap being plugged.  I know you said it's not doing it, but have you just tried riding it (carefully!) without the gas cap when the issue starts?
* Corroded fuse block assembly causing internal resistance.  Common on these bikes.  But, would be more obvious if all electronics shut off when this happens.  So probably not this, but does not hurt to check.
* Bad o-rings in carbs causing funny running when they expand.
* Improper timing adjustment, possibly causing overheating.  Did you do a static adjustment or was it performed with a timing light?
* Defective spark plug, could be hairline crack in the insulator or something to that effect which reveals itself when reaching operating temperature.  Are the plugs a proper colour?
* Vacuum sync extremely out of spec.  But, if the bike runs OK and idles fine initially it's probably OK.  Would be worth verifying, though may be difficult because bike does not run for more than 10 minutes (which is required to reach operating temperature).

I still think its a mixture of the aftermarket electrical components and one of them starts to fail when the bike reaches operating temperature.
1977 CB550K
1979 CM400A

Offline CarbasaurusRex

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Did you save the original electronics, i.e. the points plate, coils, etc?  If yes, put those on it and take it for a ride.
I will try that. If that doesn’t work, what would you suspect?


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* Vent in gas cap being plugged.  I know you said it's not doing it, but have you just tried riding it (carefully!) without the gas cap when the issue starts?
* Corroded fuse block assembly causing internal resistance.  Common on these bikes.  But, would be more obvious if all electronics shut off when this happens.  So probably not this, but does not hurt to check.
* Bad o-rings in carbs causing funny running when they expand.
* Improper timing adjustment, possibly causing overheating.  Did you do a static adjustment or was it performed with a timing light?
* Defective spark plug, could be hairline crack in the insulator or something to that effect which reveals itself when reaching operating temperature.  Are the plugs a proper colour?
* Vacuum sync extremely out of spec.  But, if the bike runs OK and idles fine initially it's probably OK.  Would be worth verifying, though may be difficult because bike does not run for more than 10 minutes (which is required to reach operating temperature).

I still think its a mixture of the aftermarket electrical components and one of them starts to fail when the bike reaches operating temperature.
Very informative. Thank you Maraakate! I’ll get back to you when I install the old condensers and points. I also did a static and timing light adjustment when I installed the new ones. Everything seemed within spec, but I’ll have to redo it when installing the old points anyway. The old points were also pitted so hopefully that won’t cause issues. I’ll keep you posted!


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Offline Maraakate

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I see the pipe is aftermarket.  Bike could be running too lean from exhaust change and is overheating.  A half-assed way to check could be pulling up the choke (either fully closed or half-way, just experiment) and/or stuffing some shop rags in the air filter (making sure it's arranged in a way that it can't be pulled in via vacuum from the carbs).

Assuming you've already check of air leaks, but if not spray everything judiciously with penetrating liquid.  Don't use carb cleaner.  Spray around the intake and exhaust boots.  Spray the top, sides, and bottom.  Sometimes the clamp doesnt full grab on one of these sides, causing a lean condition.  Spray the linkages where they meet between the carbs.  The reason I mention penetrating liquid such as PB Blaster is because in this area the linkages have felt washers and carb cleaner may disintegrate them.  See if the revs change or if the bike dies.  If it does, this is an air leak.  Check the cylinder jug to head location as well.  If the bike isn't weeping a bunch of oil from that area, then it's probably OK.

Exhaust leaks can occur as well, causing lean running but someone else will have to chime in there as I don't know how to test those areas for leaks, short of pumping some kind of smoke through it when it's on that particular exhaust stroke.
1977 CB550K
1979 CM400A

Offline Maraakate

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Did you save the original electronics, i.e. the points plate, coils, etc?  If yes, put those on it and take it for a ride.
I will try that. If that doesn’t work, what would you suspect?


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* Vent in gas cap being plugged.  I know you said it's not doing it, but have you just tried riding it (carefully!) without the gas cap when the issue starts?
* Corroded fuse block assembly causing internal resistance.  Common on these bikes.  But, would be more obvious if all electronics shut off when this happens.  So probably not this, but does not hurt to check.
* Bad o-rings in carbs causing funny running when they expand.
* Improper timing adjustment, possibly causing overheating.  Did you do a static adjustment or was it performed with a timing light?
* Defective spark plug, could be hairline crack in the insulator or something to that effect which reveals itself when reaching operating temperature.  Are the plugs a proper colour?
* Vacuum sync extremely out of spec.  But, if the bike runs OK and idles fine initially it's probably OK.  Would be worth verifying, though may be difficult because bike does not run for more than 10 minutes (which is required to reach operating temperature).

I still think its a mixture of the aftermarket electrical components and one of them starts to fail when the bike reaches operating temperature.
Very informative. Thank you Maraakate! I’ll get back to you when I install the old condensers and points. I also did a static and timing light adjustment when I installed the new ones. Everything seemed within spec, but I’ll have to redo it when installing the old points anyway. The old points were also pitted so hopefully that won’t cause issues. I’ll keep you posted!


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Some pitting is OK.  Can you upload a picture of the old points?  Just take a blank index card and run it carefully through the points when they are closed.  It will come up black.  Do this in a few spots on the paper until it comes up clean.
1977 CB550K
1979 CM400A

Offline CarbasaurusRex

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I see the pipe is aftermarket.  Bike could be running too lean from exhaust change and is overheating.  A half-assed way to check could be pulling up the choke (either fully closed or half-way, just experiment) and/or stuffing some shop rags in the air filter (making sure it's arranged in a way that it can't be pulled in via vacuum from the carbs).

Assuming you've already check of air leaks, but if not spray everything judiciously with penetrating liquid.  Don't use carb cleaner.  Spray around the intake and exhaust boots.  Spray the top, sides, and bottom.  Sometimes the clamp doesnt full grab on one of these sides, causing a lean condition.  Spray the linkages where they meet between the carbs.  The reason I mention penetrating liquid such as PB Blaster is because in this area the linkages have felt washers and carb cleaner may disintegrate them.  See if the revs change or if the bike dies.  If it does, this is an air leak.  Check the cylinder jug to head location as well.  If the bike isn't weeping a bunch of oil from that area, then it's probably OK.

Exhaust leaks can occur as well, causing lean running but someone else will have to chime in there as I don't know how to test those areas for leaks, short of pumping some kind of smoke through it when it's on that particular exhaust stroke.
When I close the chicken fully, the bike dies. Halfway, it’s low idle. Bike also has some oil leaks coming from the small top side valve cover pieces. I usually use carb cleaner to check for leaks but I guess I’ll use PB blaster this time . I guess I should check leaks first and if nothing, then replace the points with the old ones.


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Offline Maraakate

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Not just the points.  The entire points plate.   Use the original coils.  Any 4into1 electronics, if you have the OEM originals and they look like they may still be usable then put these parts on it for the test.  If all seems good, then start putting the new parts on one-by-one until you narrow it down.

I have never used the 4into1 electronics they sell.  The reviews seem hit or miss.  From what it sounded like to me, they work OK to fire it up but then weird problems crop up or they stop working very shortly after purchase.  Sometimes within a day, sometimes a week, or a month.  You get what you pay for with the cheap electronic components.
1977 CB550K
1979 CM400A

Offline Maraakate

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Also, the small oil leak from the valve inspection covers is normal.  Once you have things dialed in and running properly you can get the o-rings from Honda, part number 91302-001-020.  Beware, ~$3-$4 per o-ring.  4into1 probably has cheaper ones available as a set, and they're probably fine.
1977 CB550K
1979 CM400A

Offline gtmdriver

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I read that you've fitted new ones but it sounds to me like the coils are overheating.

Offline CarbasaurusRex

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I read that you've fitted new ones but it sounds to me like the coils are overheating.
If they are, how would I prevent that? When the bikes about to die, all I have to do is keep the revs above 2-2500 rpm and it will still run fine. Only when it gets below it struggles. Wouldnt overheated coils just stop the bike functioning completely?? Even at higher rpms?


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Offline Maraakate

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It's hard to say.  But, I would still put the old ones on there out of general principle to eliminate the cause.  The aftermarket coils on 4into1 have hit or miss reviews.

Another thing, but I am only speculating, is the advancer mechanism is acting up and when the bike is warmed up the timing is drifting because of a worn spring and then makes it hard to maintain an idle.

Either way, put those original electronics back on it, coil and points plate (including the original points and condenser).  Then take it for a ride and see if the problems go away.  Let us know how it works out for you.
1977 CB550K
1979 CM400A

Offline DaveBarbier

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Sounds ignition related. I’ll echo what was said about aftermarket points and coils. Stick with OEM. Even the old stuff is totally fine to use unless it’s tested to be bad. They last a long time.

I can’t tell if you have spark or don’t have spark when it dies. Carry and extra plug with you and when the bike dies, can you pull to the side of the road, pull off a plug cap, put your spare plug in, hold it against the engine and crank the motor? See if you have spark. Do that for cylinder 1 and 2. One coil controls cylinders 1/4 and the other 2/3 so if you test only cylinders 1 and 2 you’re testing both coils.

Offline DaveBarbier

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Another test I’d do is as it’s sputtering and dying put your timing strobe on and see if the ignition is cutting out. Do this at home obviously not out on the road. Put the strobe on, fire it up and keep the revs up so it runs and see if the flashing light is consistent. Then let the revs drop and watch to see if the light goes erratic on you. Do this for cylinders 3&4.

Offline Scott S

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 Operating the choke backwards? Horizontal is full choke, down is no choke.
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Offline CarbasaurusRex

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Another test I’d do is as it’s sputtering and dying put your timing strobe on and see if the ignition is cutting out. Do this at home obviously not out on the road. Put the strobe on, fire it up and keep the revs up so it runs and see if the flashing light is consistent. Then let the revs drop and watch to see if the light goes erratic on you. Do this for cylinders 3&4.
I did the timing light for cylinder 4 and it was fine but when I did cylinder 1 it was erratic/ not consistent. Going in direction from left to right sitting on the bike.


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Offline Deltarider

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I did the timing light for cylinder 4 and it was fine but when I did cylinder 1 it was erratic/ not consistent. Going in direction from left to right sitting on the bike.
Probably because you didn't flip the induction clamp. There's polarity to observe, so flip the clamp and it will be consistent. Also HT leads should be clean and free of grease. Close clamp well. Be very careful with that clamp! Don't drop it! Even a minor impact can damage it. If possible, use an external battery to power the strobe. BTW, are you aware that on these bikes you have a wasted spark ignition, meaning: 1+4 fire simultaneously and that the same goes for 2+3?
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Offline CarbasaurusRex

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I did the timing light for cylinder 4 and it was fine but when I did cylinder 1 it was erratic/ not consistent. Going in direction from left to right sitting on the bike.
Probably because you didn't flip the induction clamp. There's polarity to observe, so flip the clamp and it will be consistent. Also HT leads should be clean and free of grease. Close clamp well. Be very careful with that clamp! Don't drop it! Even a minor impact can damage it. If possible, use an external battery to power the strobe. BTW, are you aware that on these bikes you have a wasted spark ignition, meaning: 1+4 fire simultaneously and that the same goes for 2+3?
Yes I know it’s a wasted spark system which is why I was confused about the inconsistency. But now I know there’s a certain direction to clamp it. My advanced plate is very erratic too. Would the springs being worn out cause the issues I’m having? I thought that was just an indicator.


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Offline calj737

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You should check that fuel level in the bowls is correct. Bike on center stand, petcock ON, use the Clear Tube method for all carbs. If the level is too low, you’ll run out of gas under load, then the fuel refills enough to restart, then dies again. Viscous cycle. Sputtering and popping sounds very fuel related to me.
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Offline CarbasaurusRex

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You should check that fuel level in the bowls is correct. Bike on center stand, petcock ON, use the Clear Tube method for all carbs. If the level is too low, you’ll run out of gas under load, then the fuel refills enough to restart, then dies again. Viscous cycle. Sputtering and popping sounds very fuel related to me.
But what I don’t understand is if I rev it enough, the bike will stay on. Wouldn’t it cut off if it ran out of fuel completely??


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Offline BenelliSEI

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If the fuel level is too low, idling is difficult. Revving it will suck up the main jets.
Check your ignition switch. If it’s falling apart, vibration (at revs) May be making contact..... sounds improbable, but it’s happened to me and took weeks to figure out!

Offline CarbasaurusRex

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If the fuel level is too low, idling is difficult. Revving it will suck up the main jets.
Check your ignition switch. If it’s falling apart, vibration (at revs) May be making contact..... sounds improbable, but it’s happened to me and took weeks to figure out!
I see. Well I have a brand new OE ignition switch so it shouldn’t be that. Does insufficient fuel in the bowls just mean that the float heights are incorrect?


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