collapse

www.dimecitycycles.com

www.cognitomoto.com

https://www.townmoto.com/collections/vanson-leathers

www.speedmotoco.com

www.CITYLIMITMOTO.com

www.jadusmotorcycleparts.com

www.lostapostlejewelry.com

www.sparckmoto.com

www.pistonsociety.com


Author Topic: First Bike, First Build: 1971 CB350  (Read 749 times)

Offline NFettig

  • Posts: 9
First Bike, First Build: 1971 CB350
« on: Mar 24, 2019, 18:33:22 »
Hello everyone!

To make a long story short, I bought this '71 Honda CB350 near the end of summer in 2017 and I am finally able to dedicate more time and money to making this thing roadworthy. I bought it from an older gentleman who owned the bike since he was in high school, and while it had clearly seen better days it seemed like it was in decent mechanical condition. $400 and an hour later I backed it off the trailer and rolled it into the garage. Unfortunately, it's remained there with only a little bit of work done here and there.

This bike represents a lot of firsts for me: first motorcycle, first carbureted motor, and first points ignition system. I had been itching to own a classic for quite a few years but never could really justify spending a couple thousand dollars on a classic car--especially since I'd have to put even more money into parts at that kind of price. This Honda seemed like the perfect way to get into the nitty gritty of older vehicles while being on a budget (I've actually spent about as much on riding gear as I have on the bike itself!).

Here's the bike the day we brought it home. The picture is a little deceptive on its condition, but I think it was a pretty nice deal.


I immediately knew it was going to need tires before I took it out on the pavement. The tread depth is fine but the DOT date codes only had three digits, meaning they're likely from the '90s. I have a pair of IRC GS-11 tires, tubes, and rim strips waiting to be installed. I also (correctly) assumed that I was going to have to do some work on the wiring sometime in the future. After a winter in storage, the fuse would pop every time I switched the key on. It took me a while to figure out where the short was, but I narrowed it down to one of the power wires to the switches after ruling every other component on the bike.



While I had the bar switches apart for wiring repair I figured I would install the new bars at the same time so I only had to run the wiring once. It was kind of a pain in the ass since the repairs made the harness even thicker than it was before, but it's together and finally working properly.





That's about all of the work I was able to do on the bike for the summer. I went out and started it up a few times just to keep everything moving but for the most part it just sat in storage waiting for me to work on it. It's finally starting to be bearably warm in the garage now that it's "spring" in northern Michigan, so I spent a few hours looking over it and trying to fire it up again yesterday (emphasis on trying).

Here's where I'm currently at. Both spark plugs were wet when I pulled them so I believe I'm getting enough fuel, but the right cylinder has a very weak spark. I adjusted the valve lash and re-gapped the points but it still didn't want to fire. This next weekend I'm planning on throwing in a couple new spark plugs and verifying the ignition timing. Based on resistance measurements I don't think the problem is in the ignition coils. I'm getting ~4.5 ohms on the primary windings and just under 10k ohms when measuring from the ignition wire and either one of the smaller primary wires. There's no specs for the coils in my repair manual but it's in-spec according to some info I've found online. My carb float bowl seals and fuel lines are going to need some attention as well since I have a good amount of fuel seeping from them.



All in all I'm excited to finally be able to jump into this project on a bigger scale. My short-term plans after getting it to run again are to replace the tires, brake shoes, and wheel bearings, and to rebuild the carburetors so they no longer leak. There's a number of other little things that need to be done as well, but one step at a time. It's more important to me to get the thing running well and make sure all the things that keep me on top of the bike instead of on top of the asphalt are in good condition.

For long-term plans, I'd like to turn it into a brat style bike. I really like the more upright posture compared to the low handlebars of a traditional cafe racer, and building it like these bikes would allow me to have a passenger if I ever needed to. Here's a couple of inspiration images that are similar to what I'd like to build.






Offline 540Nova

  • Posts: 102
Re: First Bike, First Build: 1971 CB350
« Reply #1 on: Mar 24, 2019, 21:51:56 »
I made the exhaust on the bottom bike. Let me know if you're interested in one.
  Mark Kouri
  www.MerlinCycleworks.com

Sent from my Pixel 3 XL using Tapatalk


Offline NFettig

  • Posts: 9
Re: First Bike, First Build: 1971 CB350
« Reply #2 on: Mar 25, 2019, 14:35:00 »
I made the exhaust on the bottom bike. Let me know if you're interested in one.
  Mark Kouri
  www.MerlinCycleworks.com

Sent from my Pixel 3 XL using Tapatalk
Awesome, I'll keep you in mind. Right now it has the original 2-into-2 exhaust but I definitely want to put a 2-into-1 exhaust on it someday to try to get a little exhaust scavenging.

Sent from my LG-H700 using Tapatalk


Offline NFettig

  • Posts: 9
Re: First Bike, First Build: 1971 CB350
« Reply #3 on: Mar 31, 2019, 18:37:59 »
Work kept me busy this weekend so not a whole lot was accomplished in the motorcycle department. I installed new resistor caps on my ignition wires to accompany the new plugs, so once I set the ignition timing I should be able to get it fired up again provided I don't have a problem with fuel delivery. I also seem to have lost the center ball bearing that pushes on the clutch pushrod. Found one on eBay and it should arrive sometime next week.

Here's to hoping the weather starts to cooperate more so I can get some work done out in the garage. It was 19 degrees when I came home from work this afternoon.


Offline WhyNot

  • Posts: 1301
  • ~~~If it ain't raining, I'm riding~~{iii}?~~prost~
Re: First Bike, First Build: 1971 CB350
« Reply #4 on: Apr 01, 2019, 10:02:10 »
Cool project.

I'm in.
1975 CB750K5
1974 CB350F

Offline NFettig

  • Posts: 9
Re: First Bike, First Build: 1971 CB350
« Reply #5 on: May 20, 2019, 19:59:13 »
Wow, it's been almost two months. Sorry, I haven't had a whole lot to update. Work put me through Audi's Fast Track program and all of the online training for those two weeks has taken up almost all of my free time. I'm finished with training for the time being and I'll be dropping down to one job soon, so expect to see more from this soon.

Offline killerx

  • Posts: 75
Re: First Bike, First Build: 1971 CB350
« Reply #6 on: May 21, 2019, 13:27:53 »
If you haven't got your spark issue figured out yet, try taking the points cover off and checking it.
Mine would run like crap until I noticed it had a fat spark with the cover off.
I coated the inside of the cover with some RTV and then I had good spark with the cover on.
05 Victory Hammer(110hp 115tq @ the wheel)

73 Honda Cl350(Haven't decided what to do with it) SOLD

75 Suzuki GT380

Too much of everything is just enough.

Offline NFettig

  • Posts: 9
Re: First Bike, First Build: 1971 CB350
« Reply #7 on: May 23, 2019, 07:54:25 »
That's a good idea. I'll probably go ahead and coat the inside of the cover just to rule that out. Would liquid electrical tape work, or do the points get hot enough that I should use RTV? I've never dealt with a points ignition system before.

Sent from my LG-H700 using Tapatalk


Offline NFettig

  • Posts: 9
Re: First Bike, First Build: 1971 CB350
« Reply #8 on: May 27, 2019, 21:41:48 »
Spent most of the day working on the bike and finally got it to fire up once again thanks to new plugs and adjusting the ignition timing. I couldn't quite get the timing right by setting the points gap to spec and adjusting the plate, so I ended up adjusting them one at a time. It still took a little bit of effort to get it started but I'd imagine some fresh gas would help that out.



Next steps are to fix the oil leaks, see what I can do about the slightly stripped splines on the shift rod, and to get new tires, brakes, and wheel bearings installed. There's quite a bit of oil leaking from the drain plug and from behind the front sprocket cover. As for the shift rod I'm not quite sure what to do. Replacing that part would mean digging all the way into the transmission and I'd really like to just get this bike into riding shape for now. I'm thinking about buying a new shift arm and hoping that there's enough of the splines left on the rod.

Offline killerx

  • Posts: 75
Re: First Bike, First Build: 1971 CB350
« Reply #9 on: May 29, 2019, 11:14:41 »
That's a good idea. I'll probably go ahead and coat the inside of the cover just to rule that out. Would liquid electrical tape work, or do the points get hot enough that I should use RTV? I've never dealt with a points ignition system before.

Sent from my LG-H700 using Tapatalk

I would use the RTV, or liquid electrical tape.
The plain electrical tape might lose its stickiness with the heat of the motor. 
05 Victory Hammer(110hp 115tq @ the wheel)

73 Honda Cl350(Haven't decided what to do with it) SOLD

75 Suzuki GT380

Too much of everything is just enough.