Topic: Senior project for high school - 78 CB750K

[martin_uk]

Excellent

There are always little niggles to work through.

A few tips on your issues.

Check bleed nipple holes are clear and try sucking fluid through brake nipple with large medical syringe. You can also try gently operating brake with syringe connected.

With shorts, to save going through lots of fuses, you can make up test lead with crocadile clips fitted either side of fuse, connected to a 12 bulb. When the short occurs the bulb glows bright. Check nothing is shorting against rectifier.

Suspect still blockage in No1 carb,if you are getting a spark?  (if you have a timing light you could use to connect to HT plug lead to see if light flashes)  Maybe also take a look at plug, is it wet? (worth replacing just in case) make sure you can squirt carb cleaner through jet and adjuster screw (removed) and visible coming out of all the exits and clear to the small hole by carb opening.

Try disconnecting lead to oil sensor, if it still lights it may be wire is trapped (check behing gear selector/front sprocket cover and inside starter cover. Also possible to short out at warning light end or could warning light end be connected to an earth connector?
The oil warning light works br supplying a switched live (black) to warning light. When pressue below preset figure, the switch connects to earth thus completing circuit and lighting bulb. Above this pressure, switch opens, so light goes out.

[Bill/BentON Racing]

Ya, we need to heal Stella, she's just being a new bike blues b☆tch!  Got plenty of tach cables. Great job like California and others stated. Now here's your next one! Yep I can see it now! Haha.Lol,  Bill

[Restoration Fan]

Bill,
Where did you get that?  I haven't seen that one.
77 F model?

Ron

[calj737]

Bill,
Where did you get that?  I haven't seen that one.
77 F model?
Ron

....and...he takes the bait! Set the hook, Bill before you gut him too badly! 

[Restoration Fan]

LOL, cal, he's bringing back 14 bikes next month and I've already told him to let me know when he arrives so I can help them unload everything.
You don't think I offered that for purely altruistic reasons, do you?  I want to be the first to see them so I can stake my claim to the next bike to build! 

[calj737]

I understand. Yet, he still had the rod in his hand, and the hook is deep in your jaw 

[mark52]

YAHOO!!!!!! Good luck to Logan but I'm sure he doesn't need it.  Way to keep on keeping on Ron. While I know each one of these growing (is that the right word) pain problems are frustrating I think it is such a wonderful message/lesson you are leaving with him.  Sorry I could not get back up there to help out on the final push. I think I will be up in a couple of weeks and will come by to see Stella all decked out and really to dance the night away.  Doesn't look like Bill is going to give you a chance to sit back and smell the roses, is that another 750 in the picture or a 550?

Mark

[Restoration Fan]

It's an F model 750 but I don't know if it's a 77 or 78.

[Bill/BentON Racing]

It's your new project, can be riding quick...two of you! OK, 77F, followed me home yesterday. Riding it down the ramp was exciting. .....ok, my bud's helped!  Man, this is a pretty good find,K. Bill
Logan, feel proud and just tell the story....it's a good one, Bill

[danyo]

I understand. Yet, he still had the rod in his hand, and the hook is deep in your jaw 

Cal it's nothing wrong with being on a hook when it comes to vintage bikes . Logan and Ron - you guys did great job on that bike. Those small problems will be resolved soon and you'll have all summer to enjoy Stella! Congrats and good luck.

[Maurice]

Congrats to Logan and you! A hell of a job, and thank you for putting this bike back on the road.

Oil light switch is at end of circuit, meaning the bulb is powered and the switch simply closes the circuit to ground. Any short on the way to the switch will cause it to light up, so check that.

I second the need to blow the heck out of the pilot jet/mix screw circuits. Bike sounds like it's running on 2 legs and you can hear all the cylinders come to life as throttle is opened.

BTW, T-shirt and shorts? Damn...

[mystic_1]

Logan,

Wishing you all the best on your presentation today. 
Keep up the fine work.

mystic_1

[Restoration Fan]

Congrats to Logan and you! A hell of a job, and thank you for putting this bike back on the road.

Oil light switch is at end of circuit, meaning the bulb is powered and the switch simply closes the circuit to ground. Any short on the way to the switch will cause it to light up, so check that.

I second the need to blow the heck out of the pilot jet/mix screw circuits. Bike sounds like it's running on 2 legs and you can hear all the cylinders come to life as throttle is opened.

BTW, T-shirt and shorts? Damn...

Maurice,
I think you're right about the cylinders coming to life when the throttle is opened.  We only ran the camera for a short, controlled period of time there just to make sure we could get the video made for his project.  But after we turned off the camera, we let it idle for about 2 minutes.  When idling, you could only clearly hear cylinders 3 and 4 running but as it sat there idling after a few revs, you could hear #2 actually kicking in and coming to life a bit.  After turning the bike off, #3 and #4 pipes were very hot; #2 was hot but nowhere near as much and #1 was still cool.

This afternoon, I'll try taking the carbs back off the bike and go back through the jets again.  We blew them out with air before and ran a piece of fine guitar wire through them but there's always the possibility that they still aren't correct.
We initially set all of the mixture screws to be 1 1/2 turns but I'm wondering if we should try adjusting those on #'s 1 and 2 before anything else?

And regarding the shorts and t-shirt, he was just videoing and not riding.  I wouldn't let him get on the bike to ride right now because he has never ridden a motorcycle before.  I keep trying to get him to take the MSF course with me but he keeps saying that he doesn't want to ride right now. 

Ron

[Maurice]

No Ron, I mean it's still f'n cold here, I wish I could hang around in T-shirt to begin with... Today is supposed to be warmer, finally, but I'm stuck at work. I just can't win...

Yeah, it confirms a fuel issue, your ignition should be sorted out. Sometimes all it takes is riding around, flowing gas through those jets, gas is a good solvent after all. Sometimes not, then it's carb tear down time, but I would start going for a spin for sure, once you're not idling it should be all smiles.

My XS650 was like that, I was too lazy to tear the carbs down once again so I just rode it, idled like crap but ran ok once going. After a few days riding all of a sudden it's like something let loose and it idled perfectly thereafter

[Restoration Fan]

Ahh, I get it Maurice.  Yeah, it was a bit cool here yesterday as well.  I think we dropped down into the low 60's some of the time. *snickers*
Sorry, couldn't resist. 

Seriously though, thanks for the advice and comments from all of you guys.  Logan and I were talking last night after he practiced running through his presentation for me.  In his presentation, he mentions all the support, advice and even parts we've received from this forum.  We both agreed that this would have been a good project but finding this forum made it not only a great project for him but also made it incredibly fun and enlightening.  The sense of connection you get with people, many of whom you have never met, is unlike anything else I've ever experienced on the internet.

[Bill/BentON Racing]

  The camaraderie of this forum is amazing. It's like a brotherhood! K, Go Logan, you still need a 77F! Got to move it before trip! Bill

[edwardmorris]

Congratulations Ron and Logan! I must say that gold with the 4-4 chrome exhaust looks pretty sweet! Good luck with the presentation, I hope you're recording it Ron

[AintNoEasyWay]

Man, can we vote this bike of the month somehow?

This thread has been more helpful to me than any other single thread on the forum, not to mention how cool it's been to see a dad & son complete a project together like this.

[Restoration Fan]

Congratulations Ron and Logan! I must say that gold with the 4-4 chrome exhaust looks pretty sweet! Good luck with the presentation, I hope you're recording it Ron

No, I'm not allowed in there.  He will present to a panel of 3 judges...made up from other parents and volunteers from around the community.  Usually, we get a bunch of retirees who volunteer to come in for a few days and judge the presentations.
If you present during the school day, it's usually done inside of a classroom and you end up presenting in front of the 3 judges and the entire class.  But Logan's scheduled time is at 4:40 so the only other students who will be there are the other presenters who are waiting to present their projects.

There's a whole grid of things they have to account for in the project and we went through last night and were able to check off that he's meeting each one.  But a big portion of the judging is usually based on how much work the student put into the project.  So, he should be off the charts on that one.  He got a 94 on his stand-and-deliver to his teacher and the teacher's only negative response was "you need to add 30 seconds to the time".  Well, the video adds 25 seconds by design so he should be good all the way around.

[Bill/BentON Racing]

K, keep us posted, Bill

[Restoration Fan]

K, keep us posted, Bill

Logan just got home.  He said "I think I nailed it!".  They didn't tell him his time but they usually only mention time if you were over or under and he had his timing down pretty nicely so I think he was fine on that.
He doesn't know when his grade will be posted but we're both pretty sure he scored a high A on it.  He said when he told them that he had spent over 200 hours on it, one of the judges interrupted and asked, "Excuse me, did you really mean to say 200 hours?" and when Logan told him that was correct, the judge said "WOW!". 

He had 1 male judge and 2 female judges and he said at the end of the questions, all 3 told him it was the most impressive project they had seen by far.  So it seems it went quite well.

Since he's missed a lot of time on nights and weekends that he could have been hanging out with his buddies so that he could work on the bike, I told him to call his buddies and they should all go out to dinner and enjoy spending some time together.  I'm going to check with Bill and see if he's home so I can go get a replacement tach cable.

[AintNoEasyWay]

Excellent news. Congrats, Logan. 

[mystic_1]

LOGAN WINS
FLAWLESS VICTORY

[Restoration Fan]

Woohoo, got my helmet in.

I think I'm going to order a helmet for Logan, too.  At the very least, it would let him ride with me on the bike but hopefully it will get him interested in getting his own license.  If that happens, then we start looking for a bike for him at that point! 

[Johnie]

And don't forget the cycle safety course. I required my son to take it before I let him ride. You know kids "know a lot" or they think they do. My son thought he knew a lot about bikes so I let him get on my CM400 to show me what he knew. He proceeded to let out the clutch and go across the street into the ditch and laid it on the side. That was his first ride I think he learned a lot about bikes in that 100 foot ride. That was the best thing to ever happen to a "know it all."