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TurnerX19
TurnerX19 HalfDork
6/18/19 11:17 a.m.

In reply to sleepyhead the buffalo :

The Comstar wheel has separate spokes. That is not a crack, it  is just where the individual spokes but up against each other. They do sometimes have a failure mode where the rim is riveted on, especially the first year ones.  Honda recalled some in the beginning. I do not know how to tell the recalled wheels from the good ones, and the possibility of corrosion at the seam would make me watch them very closely for signs of stress fatigue.

sleepyhead the buffalo
sleepyhead the buffalo Mod Squad
6/18/19 2:44 p.m.

Thanks y’all for the education.  I thought they may be a “three piece design”... but the seam looked a bit... irregular, so I thought I’d bring it up.

maschinenbau
maschinenbau SuperDork
6/19/19 7:54 a.m.

Tires seem good to me. 5 years old and no cracking. Front is stock size, but the rear is slightly wider (120/90-17 stock).

Front: 100/90-19 - Date 1615

Rear: 130/90-17 - Date 3314

Just waiting on parts now

mazdeuce - Seth
mazdeuce - Seth Mod Squad
6/19/19 8:24 a.m.

I like this thread. If you were closer to me I'd make you try on my leathers and get you out on the kart track with crappy dirt bikes. I love cars. Love love love them, but bikes are engaging in a way that cars aren't. They are an itch that you can't ignore forever. 

Best of luck with all the new beginnings, and when it's time for a tank sticker, dont lose my email. 

captainawesome
captainawesome Reader
6/19/19 8:54 a.m.

In reply to maschinenbau :

Tires are probably fine for now, but remember it's the only two things in contact with the road. Cars are easy to just forget about as the risk is far less if one of them goes south. 5 years is at the recommended time for replacement, so I would definitely consider new when you get it roadworthy. I know I'm probably getting a bit preachy, just want you to have fun and be safe. Also kuddos to you for getting gear and a safety course. It's well worth it to learn proper riding techniques early on.

captainawesome
captainawesome Reader
6/19/19 8:57 a.m.

I would also drain the fork fluid and swap it out with some fresh stuff. That stuff gets gross and is one of the most neglected fluids on a bike. If you are feeling froggy pull the triple trees and regrease all the bearings. Shouldn't take much effort to do, but is something you immediately feel just pushing the bike around.

RandolphCarter
RandolphCarter New Reader
6/19/19 8:12 p.m.
maschinenbau said:

my wife moved out last week and we're getting divorced. It's been a long time coming but it's still really hard to deal with. It's amicable, we're young, and kid-free, so it could be much worse. I've spent far too long trying to make someone else happy who I'll never make happy, and lost track of what's important to myself. I gave up a really promising career and move us back home in a naive effort to stop the inevitable.

I'm not young, I'm not kid-free, and I didn't realize this when I should have, many years ago.

Congratulations to you for realizing that some problems don't have a solution, or at least the first solution that you wanted.

 

Edit: Nice pick up with the bike, and it looks like you are well on your way to sorting it out. I'm especially impressed with that throttle cable. People were actually riding this thing with a partial throttle and no brake fluid? Wow.

maschinenbau
maschinenbau SuperDork
6/20/19 7:54 p.m.

There's more! Remember how it starts right up and idles nice? Yeah it's doing that on only the middle two cylinders. I noticed while changing the oil I didn't burn myself on the outside headers (1 and 4) so I thought all exhaust must be cool, then immediately burned myself on number 2. First thought was coilpack, since there's 2 of them and that's how the cylinders are split up. I swap the coils and got the same result - hot middle cylinders and cold outers. Going to look at spark plugs next, but my suspicion is in the wiring. Time to read up on some diagrams. On the bright side, this box of fun showed up. I'm only an extra $80 into this project so far, including oil change. 

maschinenbau
maschinenbau SuperDork
6/21/19 1:38 p.m.

Research tells me I have the TCI (transistor controlled ignition) system, which is known for igniter modules that fail. That may not be my problem, but it's likely. The igniters for a TCI system can be over $100. Wow. 

You know what other module also takes in a reluctor signal off an engine and uses it to activate an ignition coil? Good ol' GM HEI. Yup, it's a well-documented upgrade along with the use of Cavalier coils. I still have more troubleshooting to do, but it's good to have this junkyard-friendly backup plan.

http://gpzweb.s3-website-us-east-1.amazonaws.com/Ignition/CBheiModCavCoil.html

barefootskater
barefootskater Dork
6/21/19 2:06 p.m.
maschinenbau said:

So much awesome in this picture.

maschinenbau
maschinenbau SuperDork
6/22/19 12:27 p.m.

Spark testing and timing inspection says ignition is good in all 4 cylinders. Compression test is a bit low, but not terrible for over 14,000 miles. 100-150 psi, spec range is 170+-28. The plugs in 1 and 4 are soaked with fuel while 2 and 3 look lean. I think the carbs are coming off.

On the bright side I have a new helmet and about half my gear for the MSF course next weekend. Which reminds me I need to finish the online part of the course.

Stampie
Stampie PowerDork
6/22/19 12:37 p.m.

Of the possible causes I'm not sure if the carbs being the issue is good or not. 

maschinenbau
maschinenbau SuperDork
6/22/19 12:50 p.m.

It's almost too much of coincidence that 2-3 are good but 1-4 are not, which is how the ignition system is split up. But I'm pretty sure spark is good in all cylinders. There is also valve adjustment, which could explain the spread in the compression test. But that probably wouldn't cause a too-rich-to-run condition in 2 cylinders.

maschinenbau
maschinenbau SuperDork
6/23/19 8:34 a.m.

These look pretty darn clean to me...but I'll try cleaning out the Jets anyway.

maschinenbau
maschinenbau SuperDork
6/23/19 10:06 a.m.

Cylinder 1 idle jet is clogged. Can't seem to unclog it with compressed air or carb cleaner. Cylinder 4 seems fine though, unless that initial burst of air cleaned it up immediately. I'm going to soak anyway. Also 3 and 4 float bowls were full of ants?

TurnerX19
TurnerX19 HalfDork
6/23/19 1:39 p.m.

In reply to maschinenbau :

Every animal likes alcohol (even ants), and our fuel is full of itlaugh

maschinenbau
maschinenbau SuperDork
6/23/19 5:19 p.m.

I'm apparently bad at carbs. Now it doesn't run at all. I verified spark and compression by spraying some "starter fluid" (windex bottle full of gas) into each cylinder which promptly lit off for a cycle or two. I'm not sure what I did wrong. I took them apart, cleaned as best I could, and blew out all passages with air. I took 1 and 4 off the rack and completely apart and soaked the bodies in Pine Sol. I did not take 2 and 3 off the rack, but their bowls and floats were off for cleaning, though they didn't need much. I did not replace any seals, but they all went back in. 

During the rebuild I also poured the old gas tank out and put new gas in. But the age of the "new" gas from the jug in the garage is also questionable. 

I have some reading to do. Maybe just go ahead and order a proper carb rebuild kit. 

akamcfly
akamcfly Dork
6/23/19 5:34 p.m.

Fuel petcock open? vacuum line hooked up to it?

maschinenbau
maschinenbau SuperDork
6/23/19 8:10 p.m.

Seems the 1979 and 1980 CB's don't have vacuum connected to the carbs. They changed to a different carb type in 1981 which do have vacuum lines.

Fuel petcock was definitely open because one of the carbs was leaking gas from its fuel connection tube. Might have to order that rebuild kit, because it wasn't the only bad looking seal I reused.

Just realized I never touched the pilot screw and jet. They're supposed to be 1-1/2 turns from bottoming out, so that would be a good thing to check and clean next round. Otherwise I'm stumped.

jfryjfry
jfryjfry Dork
6/24/19 4:01 a.m.

Did anything with the coils/ignition get swapped?  Even if just one of the carbs was working it would at least try to run.  And they’re obviously so simple that there is no way you messed them all up so bad that zero gas is getting through. 

It sounds like the ignition is in two pairs.  If something got swapped that would be a mistake that could keep it from firing at the right time. 

 

maschinenbau
maschinenbau SuperDork
6/24/19 8:31 a.m.

You're right, the ignition is split into pairs. There's only two ways to mix up the pairs - the wires going into the coils and the plug wires themselves. It's a completely split system from pickup coils (it has two 180 deg apart) to the coils themselves. But I'll check anyway. 

maschinenbau
maschinenbau SuperDork
6/25/19 9:13 p.m.

I got it running again! Combination of a few things. First, I messed up the choke plates when I first reinstalled them. They were binding up but it's all good now. Second, pilot valves are adjusted correctly but they weren't really that far off in the first place. I did nothing else to the carbs. Then I cleaned every connector in the ignition system with electrical contact cleaner and dielectric greased the plug boots both ends.

It started! But was running about as rough as before and the 1-4 pipes still weren't getting hot. I then took a look at the pickup coils. Gap should be 12 to 16 thou, and it was. So I adjusted timing a little while I was in there. Slightly advanced, so I backed it off a bit. You can adjust timing by loosening the 3 big screws and rotating the backer plate. The blue wires are cylinders 1-4 and yellow are 2-3.

So I'm pretty sure it's ignition related. I pulled the plugs on 1-4 and regapped them down from the standard 26 thou to only 20 thou. Runs much better on startup! Cylinder 4 pipe immediately getting hot just like 2-3. But 1 is still cool, except sometimes when the idle suddenly surges. I think I simply just have weak spark. That HEI conversion is sounding awfully appealing.

I also got the new cables installed and adjusted, and the new cafe style grips on to match the seat. Check this retro cool cockpit.

Yes, the bars will hit the tank, which conveniently already came with "clearance" for them. The brake master is weeping a bit, so I'll replace that too. I love how cheap bike parts are.

With all that done and the engine mostly running, I took it for a spin in the neighborhood. Wow, motorcycles are REALLY fun! Even when you can't rev past 5k because the mechanical advance is probably rusted up (should have checked that earlier). Can't wait for my MSF course this weekend. The only mishap during the test ride was a shifter that just kinda fell off, because I had the chain cover off earlier to clean the chain and forgot the shifter was still loose. First roadside moto repair in the books. Oops.

mazdeuce - Seth
mazdeuce - Seth Mod Squad
6/25/19 10:29 p.m.

When you take the MSF course, remember that it's not a competition. Your job is to learn and do the exercises successfully, not beter than the dude in front of you. I watched someone do an auto fail because they were trying to out brake their friend and dumped the bike. Depending on what bikes the class is using the exercises can be harder than they have to be. I was stuck on a VERY small cruiser which made all of the tighter maneuvers hard because the handlebars were about hitting my thighs. Have fun, pay attention, wear safety gear. 

Stampie
Stampie PowerDork
6/26/19 6:41 a.m.

I like those grips. Hopefully I'll see the PO Friday and see if he's found the seat cover. 

¯\_(ツ)_/¯
¯\_(ツ)_/¯ UberDork
6/26/19 7:11 a.m.
maschinenbau said:

Wow, motorcycles are REALLY fun! Even when you can't rev past 5k

This should be Harley-Davidson's new slogan.

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