Author Topic: new from Pittsburgh (Read 8117 times)

Super400SuperSport · « **on:** November 04, 2012, 01:19:40 PM »

Hello All! I just recently purchased a 1975 cb400f Four SuperSport for $300. I am having a few issues. this bike has been in a heated garage since 1986 and fuel left in the carbs created 1/8" of hard varnish.

cleaned the carbs, oiled cylinders, replaced spark plugs, cut 1/4" off plug wires, found multiple shorts and wiring problems (which i still need help with), didn't spark before and still doesn't. the reason i picked this bike is because my dad has the same exact bike/year/motor size. anyone have any ideas on these headlight bucket wiring or why the bike wont spark. I'm starting on one thing at a time and think the wiring could be part of the problems I'm having.
the chrome is in good shape

trying it on for size

Wiring problem with the light blue/white, orange/white, black, and 2 missing greens, brown, brown/white, light blue, orange. someone already messed up the wiring. uggg!

let me know if anyone can help me out with my frustration. the old book isn't helping much.

keiths · « **Reply #1 on:** November 04, 2012, 06:01:15 PM »

Welcome to the forum. This link should help. http://oldmanhonda.com/MC/wiring350F.html If I remember correctly, not all connections are full. Check your ground connections first.

Stev-o · « **Reply #2 on:** November 04, 2012, 06:33:28 PM »

Welcome. Good battery?

MoMo · « **Reply #3 on:** November 04, 2012, 06:42:19 PM »

Try the simple solutions first for no spark-clean the points with a fine point file, some electronic cleaner and then blow out with air. The most common no spark problem I have run across in all the years I have worked on bikes is dirty points...Larry

Super400SuperSport · « **Reply #4 on:** November 05, 2012, 05:52:45 AM »

So last night I was sitting in the garage just thinking and thinking and thinking then thought of a brilliant plan! I don't know if you guys do this but I was thinking about the kill switch and how half the wires in the bars were grounded so I cut the Black/white wire and connected it to the black wire. Now I have a nice bright blue spark! I tried jumping it before and blew the main fuse so I figured there was resistance. Thank god I have my trusty multimeter. Now the stupid wires up front are still bugging me behind the headlight bucket. I really do need a reference picture if anyone has one. Tried firing her up last night and noticed that either my float is hanging up or a rubber tube going to the carbs are clogged or I just suck at cleaning carbs. The fuel started pouring out number 1 bowl. Before I did anything and put gas in it it was number 3. So prob something with the tubes since I mixed them up. What do you guys think. I thought these things use barometric pressure to work or something. I'm sorry I'm rambling. I'm not the best at typing. Thanks for the quick replys! I feel so welcome already!

Stev-o · « **Reply #5 on:** November 05, 2012, 05:57:14 AM »

Could be float hanging up, try gently tapping on it with a screwdriver handle. Black hoses under carbs are for overflow, nothing will come out under normal operation.
Carbs are gravity fed.

Super400SuperSport · « **Reply #6 on:** November 05, 2012, 10:47:28 AM »

thanks guys! I have the diagram in the book keiths, and i have it saved on my phone =D
Stev-o the battery is brand new and i did read about tapping on the float and will try that next chance i get back in the garage without getting yelled at by the old lady. haha.
Momo, the points are clean and look pretty damn new. i was worried about the bike not being kept up on but it looks like someone was Throwing parts at it to get it running and it seems like it was just the handle bars.

ill keep plugging away at it! thanks again for the help!

Super400SuperSport · « **Reply #7 on:** November 06, 2012, 12:09:08 PM »

It looks like I am going to have to take the carb apart again and figure out what's going down. The petrol keeps coming out of that first tube and lightly tapping on it didn't do anything in slowing it down. Is there a way to adjust the floats or am I just going to have to rebuild them? I'm afraid to go in there because it smells like if I light up a smoke ill blow up. Haha! Charging up the battery again because I've been using it so much trying to figure out this spark thing. But a couple nights ago I charged it and accidentally fell asleep and forgot to shut off the charger but am hoping it didn't ruin the battery. Ill post up some pictures of progress when I make some. =D

thanks for the help!

Stev-o · « **Reply #8 on:** November 06, 2012, 07:38:05 PM »

Don't use an automotive charger on that small battery for an extended time, trickle charger is best.

Yes, you can adjust the float but I bet it's stuck open.

Super400SuperSport · « **Reply #9 on:** November 06, 2012, 08:58:22 PM »

I used a $20 one from my work which is a small one for motorcycles and ATV's. I am pretty sure I have to pull it apart and use the guitar string I keep reading about and just get that fuel through. I tried starting it and fuel won't feed in there but starter fluid worked so it at least moves the motor well.. I started off with changing the oil tonight because I didn't want to order a filter and thought that maybe my work will have them and they did which took me 20 min to find for some reason. What do you guys think about me painting the engine while I'm taking stuff apart? I was thinking black/satin black.

I also bought some carb cleaner tonight and I have some chem dip from when I cleaned them last week. There was about 1/8" of varnish in there so I wouldn't be surprised there still is more. The bike has been sitting since 1986 and dude didn't drain the fuel before he let it sit. Thank you for the help! I am seriously lost on bikes and mildly know how they work, but I'm more familiar with cars. I'm a mechanic at a Pepboys here in Pittsburgh but no one knows too much about bikes where I work. Ill def keep you guys updated. I'm getting excited about this bike! I've been working on it since the beginning of October trying to get spark and other small things.

Super400SuperSport · « **Reply #10 on:** November 08, 2012, 04:14:16 PM »

So tonight I got the bike kinda running after 26 years of not being ran! Found that the fuel ports on the carbs were super clogged with varnish I didn't get when I dipped them in the chem dip. I used a steel wire to poke in there and clean them up and got some flow out of them. Cylinder 2 float was sticking so I used a lighter and burned the varnish off. Really smokey too!

Now the problem I ran into after I got it started was it def needs the carbs adjusted but cylinder 3 wasn't firing so its probably the spark since it should be getting fuel. Ill pull the bowl and see if there's fuel in there but ill check the spark first since that's easiest. A ton of rust shot out the muffler and revved at 1k then 2k then 3k then 4k then 5k and stayed steady at 5500 rpm. Most likely a carb adjustment issue.

MoMo · « **Reply #11 on:** November 08, 2012, 04:50:42 PM »

Dipping the carbs in not sufficient. You need to remove all jets( main, midrange and pilot) and thoroughly clean all passages. With a bike that has been sitting that long you may even have to separate the carbs and clean fuel passages and tees(and probably the gas tank too). Do one carb at a time so you have a refence to reassemble...Larry

Super400SuperSport · « **Reply #12 on:** November 08, 2012, 07:00:10 PM »

I had all 4, all the way apart and gently cleaned all them and dipped them. I didn't want to ruin the brass pieces. I wanted to see if it would run before I bought too much stuff. I'm going to be in a huge hole once I have to find a frame. I paid $300 for it but the frame will be $350. I want to do it up right but that's why I got it right before winter so I can have a project. I'm learning though. The carb was completely stuck like it had glue the first time I tore into it which was the varnish. The throttle wouldn't even move because it was so bad. But in the time I've had it I think I've done pretty well without being a bike mechanic. Thank you for the info man! I knew I would have to rebuild it but ill hold off for a bit.

MoMo · « **Reply #13 on:** November 08, 2012, 07:24:02 PM »

Why do you need a frame? I have one minus title if you really need one....Larry

Super400SuperSport · « **Reply #14 on:** November 09, 2012, 07:08:32 AM »

I bought the bike with no title and there isn't records of it on file at the DMV whatsoever. I need a titled frame before I do anything else because my girlfriend hates me already about getting this bike and if she finds out about this, I'm dead! Lol!
I really tried finding out if it was stolen but the DMV it was registered to had no record. I've been going nuts with that part of it. It was registered in Virginia back in 86. Dude that bought it from the dude in VA has killed himself and his wife sold it so now I have it. Thanks for the offer on the frame but I need one I can register and really don't feel like going to the courts trying to get a court appointed one that can take a year and $250 or just buy a new frame for $350. So stressful!

MoMo · « **Reply #15 on:** November 09, 2012, 11:54:44 AM »

In PA your only option is to find a titled frame

There is a website that insurance companies use to check for stolen bikes but I cannot remember the name

I once used ITS in Nevada but it cost 250 and I had to fake a bill of sale. Don't spend any money until you get a title, been there...Larry

Super400SuperSport · « **Reply #16 on:** November 09, 2012, 01:01:27 PM »

I'm still kinda able to put money into it because my father has the same bike and his is in worse shape and hasn't been running since 1989 so worst case is ill give him the bike and pick up another or just buy a frame. Either way $300 isn't bad.

Super400SuperSport · « **Reply #17 on:** December 22, 2013, 02:29:31 PM »

I've made a bunch of progress since my last posts because I am actually allowed to work on it. I know this is Super sport blasphemy but here's some pics.

I also want to know if any one has a idea on what would cause a super high idle. I've searched high idle and everything for the past week and can't find anything that would cause my bike to idle so high even with the idle knob not even touching anything. I can't adjust the carbs with it idling at 5k. I'd greatly appreciate the help. Thanks for checking my stuff out.

70CB750 · « **Reply #18 on:** December 23, 2013, 04:27:59 AM »

Welcome!

MoMo · « **Reply #19 on:** December 23, 2013, 08:49:44 PM »

For fast idle the usual culprit is the slides not returning all the way. Cable not adjusted correctly, slides sticking, bent throttle plate, improper cable routing....Larry

Super400SuperSport · « **Reply #20 on:** December 23, 2013, 10:28:52 PM »

I'm actually going to head down stairs right now and check that. I was kinda thinking for a second that I might have put the carbs together wrong eg. Got the slides mixed up. I hope I didn't do something stupid like that but you learn from your mistakes. Thanks MoMo!

Super400SuperSport · « **Reply #21 on:** December 23, 2013, 11:09:12 PM »

You are Absolutely right MoMo! I knew this wasn't right and stupidly put the slides in wrong so I'm going to take them apart for the 5th time and reassess the situation again. Not to put the blame on anyone but I had my carbs all apart on my box at work and corporate was in town so someone put my carbs all apart in a box and said they kept them in order but I know one of the guys likes to mess around a lot and probably mixed up a few things. He's the one guy in the shop who knows about bikes and I have a feeling he messed with me because I told him my bike has a high idle and he started laughing. He's a jerk but you never know.

Thanks man. It's always the little things and the hardest to get to.

MoMo · « **Reply #22 on:** December 24, 2013, 12:18:20 AM »

hey, you'll become a 400f carb expert!! The part I hate is putting them back on, even with strapping the air box back it is still a pain-and I've probably done it 50 times or more. Doesn't say much for my dexterity does it?...Larry

Super400SuperSport · « **Reply #23 on:** December 24, 2013, 01:03:37 AM »

Trust me, I'm 27 and from working on cars and trucks my whole life I feel much older than I'm suppose to. My hands don't grip so well and lock up from carpel tunnel and my knees and hips are bad and crack and lock up. I'm falling apart. No manual dexterity here. Ha!

So when you said bent throttle plate I started thinking.... When I first got the bike there was a TON of varnish on the slides and I kept twisting and twisting hoping to get them free which was stupid on my part but I think the needle plates can possibly be bent from that. I'm not 100% but definitely something to look into I guess. How would I go about fixing that? A rubber hammer? I took the carbs down and the slides sit completely flat without everything connected. I'm a bit confused. Also, should I change my needle while I have it all apart? That is the one thing I didn't replace when I rebuilt the carbs because I forgot after I replaced everything in the bowls. What notch do you think would be a good starting point for pod filters? I know the jets won't be right but I just wanted to get this one thing figured out before I start changing a million things if I can't get the idle down.
Thank you Larry, you've been a great help.

MoMo · « **Reply #24 on:** December 24, 2013, 07:29:40 AM »

Did you remove the emulsifier tubes when the carbs were apart? I would not replace the needles with aftermarket ones unless the old ones are damaged(too many poorly made parts). The cable holder gets bent as does the plate...Larry

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Author Topic: new from Pittsburgh (Read 8117 times)