Author Topic: (cb750K1) Yolanda was dying, then died, now wont start (got it running!) (Read 7964 times)

cheftuskey121 · « **on:** May 21, 2013, 10:06:26 PM »

I did not really want to post, but I am tired of searching and searching, mostly because I don't really know what search for. My knowledge in the troubleshooting area is even less than my wrenching and understanding of mechanical things.

hope you guys dont mind reading, I will try to separate things. there is a lot on my mind and I truly hope someone can read through this and answer many of my newbie questions.

So I had the bike running great. throttle response was immediate, everything seemed wonderful. other than my oil leak on the stator cover (which I am going to try and fix in the next day or so....new gasket, checking for stator cover flatness, and sealant on the stator wiring grommet). my minimal knowledge of bikes in general leaves me out to dry to diagnose anything, mostly because I have no idea how things are supposed to sound, feel, look like.

after 2 hours of riding the other day the bike started stuttering from 2k-3/4k. dangerous trying to ride like that. then it actually stalled out. I only have kick start right now. I bought new motor brushes, and hope to get that replaced when I have the stator cover off. its much easier to test things with electric starter I would imagine. I have a brand new scorpion agm battery that is charged correctly. I have tested it many times with my voltmeter and it is reading properly. my charging system seems to be ok too because, well, it hasnt died from the battery going, and when I get it back in the garage after riding its over 75% when I throw it on the charger. it takes about 20 kicks to get the bike started from cold, and even a few from hot. I have a pamco ignition, and the recommended ultimate coils, ngk spark plug ends that read 5ohm resistance, and ngk iridium spark plugs. I believe there is only one way to wire the pamco. if I reverse the wires that go to the coils I believe it will not start at all. I had the bike running for a few hours so I know it works. the timing was NOT set. it was ballparked and it ran.

I also have not adjusted my cam chain, and I have not checked the tappets. I have not synched the carbs, although considering the bike wont run or idle now I cant sync anyway. I know there is a lot of stuff to check. I am curious if these things I have not checked would make the bike run fine, and then stop suddenly? no clanks, bangs, knocks, or any funky noises happened while I was riding. my oil smells a little of gas. I pulled the plugs and at first the plugs were sooty. I loosened the air mixture screws 2 more turns out and then after a bit of riding I could see they were considerably whiter (lean yes?).

so I feel like I am not producing the proper spark when I kick it over. it should not take 20 kicks to make it go. choke has no effect on this. in fact I cant get it started with the choke at all. when I get it running and turn the choke on the engine dies, I am assuming this is normal? I have to adjust the idle screw about three turns in to get it going, then let it warm up and adjust it back down. also normal?

I am pretty sure I want to go back to honda oem coils and points to help eliminate any other potential problems, and then pickup hondamans points ignition. all of my wires are connected properly, although I have not recently tested my coil wiring. I can work with electrical stuff well, its the engine/mechanical stuff I am not good at. I should also note I am running stock 40 slow jets, 110 main jets (recommended because of my 341 pipes). everything in the carbs are brand new oem. I raised the clip on the needle one (lowered the needle one notch.....second from the top instead of 3rd from the top) as recommended to not foul the plugs.

I have proper fuel flow. I have not pulled the carbs out to check if they were clogged, I do not suspect they are, but I dont know if that could cause this condition. carbs have to come off when I get to the starter. A not about the starter. it works when I have the spark plugs out, but when they are in it just does not have enough oomph to turn the engine. solenoid is brand new. even jumping from a car battery (car is OFF!) does not have enough cranking power to turn it. so I am replacing the starter motor brushes. do I need to get into the stator and the starter clutch too? or take it one step at a time?

when the bike did start up it was running on all cylinders, I could feel air out of each pipe. I was not in a place where I could check that when it was idling rough, because it died so quickly, so I don't know if it was failing on cylinders or not. just another observation. I feel like I've read that one or two cylinders can die but the bike can still limp. in my case there was no limping. just dying.

thanks again for any and all that have read this far. I really want to get on the road again. after 6 months of restoring having the bike die is very discouraging. So I guess I am just looking for things to check/test. I dont have the knowledge to just know what to look for. any and all advice is appreciated. thanks

scottly · « **Reply #1 on:** May 21, 2013, 10:16:23 PM »

Quote from: cheftuskey121 on May 21, 2013, 10:06:26 PM

I pulled the plugs and at first the plugs were sooty.

Sooty plugs are generally caused by a rich mixture, not ignition problems. With out fire, there can be no soot...

cheftuskey121 · « **Reply #2 on:** May 21, 2013, 10:21:12 PM »

Quote from: scottly on May 21, 2013, 10:16:23 PM

Quote from: cheftuskey121 on May 21, 2013, 10:06:26 PM
I pulled the plugs and at first the plugs were sooty.
Sooty plugs are generally caused by a rich mixture, not ignition problems. With out fire, there can be no soot...

correct, and then I turned the air mixture screws out a little and after I pulled the plugs they were too lean. but now I cant get it to start. my leg feels like its going to fall off after 20 kicks and it just wont go like that spark is not happening now. I thought maybe there was too much fuel flooding so I opened the choke and the throttle to let air in. no dice. I cant have ignition without spark. why am I kicking it 20 times before it cranks? well now it just wont start...but i WAS kicking it 20 times

Tews19 · « **Reply #3 on:** May 21, 2013, 10:22:22 PM »

If sooty rich as scottly stated. But if sooty and wet most likely no spark. As scottly stated no fire.

cheftuskey121 · « **Reply #4 on:** May 21, 2013, 10:24:18 PM »

I dont recall them being wet. looked sooty dry.

scottly · « **Reply #5 on:** May 21, 2013, 10:25:20 PM »

If the plugs are clean (bone white insulators) and dry, you have a lack of fuel...

scottly · « **Reply #6 on:** May 21, 2013, 10:27:04 PM »

soot will short out the spark. Burn the soot off with a propane torch...

cheftuskey121 · « **Reply #7 on:** May 21, 2013, 10:29:04 PM »

ah this is good to know, thanks scottly. tomorrow (well in a few hours when I wake up I will try some of these things). I sure wish the #2/#3 plugs were easier to get out and in

scottly · « **Reply #8 on:** May 21, 2013, 10:30:55 PM »

Keep us posted on your findings.

jerry h · « **Reply #9 on:** May 21, 2013, 11:24:50 PM »

Hi Chef,
Since the bike was running, then quit, don't start changing things blindly.... you'll just compound the questions. Start SIMPLE.... you need basically 2 things to have a running engine, gas and spark. Focus attention on those two.

Maybe start by taking a plug out, turn key on, and kill switch

Connect plug to its socket, and set it on the engine so just the threads are touching the engines metal.... have someone kick it over and see if the plug is sparking (may be easier to remove all 4 plugs for ease of kicking). If not, try a new plug with that test (to take the sooty plugs out of the equation), if still nothing, that's your problem, no spark, then you can work on that. You can then start from the battery and work forward to find the problem. If its a good spark, then move on to the fuel part.

Do you have gas flowing to the carbs? If so, maybe check each carb, open each drain screw and see that gas is flowing out of each.... (I always like to have an extinguisher handy when working with gas) Maybe pop each bowl off (turn off gas first

) and see what the bowls/floats look like.... dirt? And finally if the gas is getting to the carbs.... is it getting into the engine? If your spark was good, but no gas, then you can focus attention in that direction.

These are the 2 things you need to be concerned with now. Don't worry about changing coils, adjusting valves etc. Verify you have good spark first (its easier

), then move on to gas, and let us know!

cheftuskey121 · « **Reply #10 on:** May 22, 2013, 06:37:25 AM »

hey guys thanks for the suggestions so far. good info! so I pulled all my plugs today, they were a little lean, and hit them with the torch for a little. I went through and tested each one by one (killswitch on and plug threads grounded....I even tried killswitch off and plugs floating in mid air to test everything I can. no spark. nada. zip. just to make sure I also threw in some of my older NGK d8ea plugs (they were sooty so I burned those too). also nothing. did I cook the plugs to death by torching them? if not then I definitely have lack of power to my coil cables. if it is possible to cook the plugs too much with a torch, then I have a new set of spark plugs on order already to me.

is there a way to test just the spark plug?

I know I am getting proper fuel flow to the bowls. I did have an overflow on #2 but it was the float getting hung up on the new gasket. I took care of that. fuel is filling the bowls nicely and the floats are doing their thing. so after this spark plug test I feel affirmed that I am just not getting the spark I need.

Tews19 · « **Reply #11 on:** May 22, 2013, 06:43:37 AM »

Ahh! I figured it may be not running on all cylinders. Trim the wire about 1/4 inch. Screw the cap on. Before starting pull the points. See if you are getting spark. #$%* you not using the stock points I think. Anyways trim the wires put the spare spark plug back on, ground it then attempt to see if you have spark. I never heard of killing a spark plug so no input on that

ekpent · « **Reply #12 on:** May 22, 2013, 06:50:10 AM »

Always a good idea to keep some new plugs on the shelf if nothing else just for testing like this to take the baddies out of the equation. Sounds like you are finding your problem. Maybe some testing along that electrical loop will show a problem.

cheftuskey121 · « **Reply #13 on:** May 22, 2013, 06:56:39 AM »

yeah Nick, I have the pamco. the install was pretty simple and the backing plate is centered under the points cover. that didnt shift so its not like its "out" of timing all that much. granted I have not used my strobe light but if the whole plate did not rotate then that cant be the cause/failure on its own. I will trim the cables and try again. they are new cables and ends by the way, but it cant hurt to check.

ok checked that and its not the ends of the cables.

ekpent · « **Reply #14 on:** May 22, 2013, 07:00:53 AM »

Are all 4 plugs not showing any spark at all across the board ? All other electical circuits like blinkers,headlight etc are fine ?

cheftuskey121 · « **Reply #15 on:** May 22, 2013, 07:07:36 AM »

ekpent, you are correct. all other electrical is fine, no spark on all 4 coils. triming the wire did not help. I know I should be testing things with my multimeter but I don't exactly know what I am probing to test for.

JimJamerino · « **Reply #16 on:** May 22, 2013, 07:10:27 AM »

To me, it sounds like a wire or connector worked its way loose.

brandEn · « **Reply #17 on:** May 22, 2013, 07:11:22 AM »

Hi Chef, I had a problem very similar to this on my rebuild. Almost identical in fact. Turned out to be a bad/loose connection in the headlight bucket. If memory serves me right it was one of the wires from the bar switches.

cheftuskey121 · « **Reply #18 on:** May 22, 2013, 07:15:13 AM »

and just as soon as it started it was OVER! i have spark now on all four. on these "ultimate coils" the two leads are on one side of the coil toward the neck. they are blade style connections, and apparently pressing them on isnt enough. I was able to wiggle them around and got spark on all four wires. time to go get my soldering iron. that exactly what I thought it was going to be but I expected to take off the tank and see them completely loose/off. they look just fine. looks can be deceiving. now hopefully in few minutes I ca get her fired up and see if that stuttering problem goes away (since there will be a secure connection now. as much as I love connectors solder isn't going anywhere.

cheftuskey121 · « **Reply #19 on:** May 22, 2013, 08:12:25 AM »

ok. so now I have spark. got my plugs back in, and had to kick it 30 times to start. then after it idled for a few minutes it died when I tried to give it any more than 1/4 throttle. would not start back up even after 20 more kicks. I have to get ready for work but later I will double check I am getting spark after I soldered those connections, and then its on to air/fuel.

I feel like I need to understand how the fuel works. it drains in to the bowls until the floats rise and plug up the seat. but then how does it get into the spark plug area? I can't see a way that the kicking mechanically moves the fuel. is it supposed to be sucked in by compression? what are my next areas to test. my leg is going to look like a horses soon enough!

Vinhead1957 · « **Reply #20 on:** May 22, 2013, 08:16:44 AM »

Sounds like the kill switch has intermittent power! Like he said check headlight bucket connections. It could be power is intermittent to the coils

brandEn · « **Reply #21 on:** May 22, 2013, 08:33:14 AM »

They work on a principle of venturi. Google Motorcycle Carburetor Theory for hours of enjoyment. And check those connections

cheftuskey121 · « **Reply #22 on:** May 22, 2013, 08:36:10 AM »

I am getting steady spark on all four cables (it looks like each plug sparked a few times per kick). Wouldn't the intermittent kill switch cause me not to get spark though? I already soldered the leads going to the coil because they were loose. it was testing fine with spark. I'm not sure what the kill switch has to do with engine rpm/throttle response. it died when I gave it gas. I think its not getting the proper fuel/air to start with anything less than 20 kicks. I will check in the bucket later tonight though.

cheftuskey121 · « **Reply #23 on:** May 22, 2013, 08:39:10 AM »

Quote from: brandEn on May 22, 2013, 08:33:14 AM

They work on a principle of venturi. Google Motorcycle Carburetor Theory for hours of enjoyment. And check those connections

Homer voice: maaaagggggic. so the engine sucks in the fuel and air and it atomizes upon exiting the carbs into the spark chamber. I feel like maybe thats where its going wrong. will definitely check bucket connections later. I feel like I am going to go on a solder frenzy...such a more secure connection.

Irukandji · « **Reply #24 on:** May 22, 2013, 08:53:32 AM »

You did say that the oil smelled of gas. Dont run the bike for more than 60 or so seconds if it does start.
But with the gas smell that means you got stuck floats.

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Author Topic: (cb750K1) Yolanda was dying, then died, now wont start (got it running!) (Read 7964 times)