72 CB350 For the Daughter

If tyres feel even slightly slippery it's always a good idea to scrub them down. Did you watch them being mounted? I've seen all kinds of crap being used as a 'lubricant' (from WD40, various hand cleaners, degreasers and even silicon spray) soapy water always seems OK and is easy to wash off
 
That bike looks way nicer than I had expected. Nice work.

Check the AVON website for recommended pressures and the Owners Handbook if you can find one. I suspect that 28-32 would be closer, and yes: wash the tires just in case there is something on them.

I just checked and the FSM says 25.6psi in front for normal riding and 28.4 for high speed riding. For the rear it says 28.4psi normal and 31.3 high speed, so maybe drop them to 26F-28R and see how that feels.
 
Well I am back from my trip to the mountains. I would like to report that the bike ran great, but that just wasn't the case. The mid range was horrible. It would spit and sputter like it wasn't getting fuel. Not sure at what RPM level it would start, but it would run crappy up to 7,000 rpm. After I rolled past that it was like the bike came alive and would race to redline and run very smoothly. So it looks like I need to get back into the carbs. I need to find the diagram of what jets do what and at what rpm/throttle position. I re-used the brass when I rebuilt them, but used new oem O-rings. Because of the stumbling I couldn't get into and through the corners as I would have liked so my pictures are kind of boring. A friend of mine did take this sweet picture for me though.



Going up


Coming down
 
The bike is beautiful man.

Here's a list of the stock jets as a baseline. Some PO may have changed them out at some point, going back to stock is a good place to start
612d1332207703-proper-jets-settings-carbs-w-aftermarket-parts-carbspecs.jpg
 
Well if the community wants to vote for something I was nominated for photo of the week at Deals Gap and I need your help and votes to win. All you have to do is click the like button. You can vote using every device you have. I am the 7th photo down on the right (black leathers on a light green bike). Vote early and vote often please. http://www.129photos.com/
 
Harsh said:
Well I am back from my trip to the mountains. I would like to report that the bike ran great, but that just wasn't the case. The mid range was horrible. It would spit and sputter like it wasn't getting fuel. Not sure at what RPM level it would start, but it would run crappy up to 7,000 rpm. After I rolled past that it was like the bike came alive and would race to redline and run very smoothly. So it looks like I need to get back into the carbs. I need to find the diagram of what jets do what and at what rpm/throttle position. I re-used the brass when I rebuilt them, but used new oem O-rings. Because of the stumbling I couldn't get into and through the corners as I would have liked so my pictures are kind of boring. A friend of mine did take this sweet picture for me though.

Pics look good and bike looks great.
Welcome to the mid range problem when K&N are fitted.
The carb problem can't be fixed with 'new' brass bits.
Some internal modifications are needed.
 
I didn't fit K&N's. I used new stock (from David Silver Spares) air filters.

Any suggestions on what to look for/check? I cleaned the carbs with spray carb cleaner (did not dunk them) and watched it shoot out through the holes in the carb. Ran some violin string through the emulsion tubes and slow jets to clear them. Oiled the felt washers, set the float heights, new oem O-rings.
 
So the story with the Miata...the week before I went there a local kid was more than likely going too fast and lost control of his car at 10:30 at night. Bounced from the ditch across the road and off the side of the mountain into a tree. He along with his passenger were killed. Tragic for sure. There was a drive down the mountain for him. Killboy did a big thing for it. I kind of understand the sentiment of the people with the sign. A buddy of mine said...he messed up and killed himself and someone else. That's not something that should necessarily be celebrated much less be benefitted/profited from.


I am still voting in the hopes that the people who run the website take into consideration the above. As a another buddy told me, votes should be for a good shot so someone can get a nice poster. They should not be to memorialize someone via a random sign held next to a Miata.
 
Harsh said:
I didn't fit K&N's. I used new stock (from David Silver Spares) air filters.

Any suggestions on what to look for/check? I cleaned the carbs with spray carb cleaner (did not dunk them) and watched it shoot out through the holes in the carb. Ran some violin string through the emulsion tubes and slow jets to clear them. Oiled the felt washers, set the float heights, new oem O-rings.

Forgot you have stock air boxes and filters. Re-set float level to 26mm (with brass floats)
Did you use Kei-Hin pilot and primary main jets? Aftermarket have the wrong size holes but originals may be oversized due to 'cleaning' with bits of wire over the years. Stock primary main jet works best although Trek has found a slightly smaller one can clean up mid range on his 360 (350 works the same though)
 
Yes I re-used the Keihin jets. They looked to be in good shape, but I didn't measure the holes. The emulsion tubes were all clogged, which is what I used the violin wire on. I find it odd that all of the kits come with #70 primary jet when #68 was stock. I am having a hard time even finding a #68 much less something smaller.
 
if it's running this bad i'd fit new jets and emulsion tubes. anything you had to poke wire through to clean is worth replacing just to rule it out.

using an oil can to pump oil through the pilot circuit is a good idea too. it moves stuff compressed air won't.
 
The new 'primary main' jets are longer than originals but you can get them as air jets for a newer carb (I think? )
You'll have to do a bit of searching around, pretty sure Jets R Us has pictures plus descriptions (diameters, thread pitch, etc)
 
I was just about to reply to your PM. I did find Jets R Us has #68 (stock) as well as a #65. Although I worry about running lean if I were to fit the #65.
 
Pretty sure you can still get primary main jets, except they are now used as air jets in some carb.
Try Jets R Us, I think they have pictures and descriptions, thread size, diameter, length
 
Jets R Us does have pretty good descriptions. I have the oem part numbers for the primary man jets so I might swing by my dealership today on the way home and see what they have.
 
Ordered some rebuild kits for the carbs to hopefully fix my running issues. I went with all new brass pieces vice just cleaning the old stuff and replacing the o-rings like I did previously. Get everything back together and the bike wouldn't fire up. I had zero spark on both cylinders. So I Pulled the tank to check the wiring to see if I accidentally disconnected something while I was fiddling around. All wiring had good and solid connections. Power was where it was supposed to be and grounds were perfect, yet I was getting zero spark. So I swapped in the wife's electronic ignition and the bike fires right up. So it looks like I get to play the warranty game with the manufacturer. People have had issues with him before and I suspect I will too. My issue is that I purchased it more than a year ago even though it wasn't used until a couple of months ago and I can prove that via my build threads.

Now I wonder if it was the ignition that was causing the running issues the entire time and not the carbs.
 
Replacement electronic ignition shipped today and should be by the end of the week. Should be here by the end of the week so hopefully I can get it installed, set, and running by this weekend.

I need to figure out something to do with my garage though. I have a 1980 CB750 in there that I am helping a member here get up and running and I am looking at buying a new bike within the next couple of weeks. Hopefully I can find a Triumph Tiger that I like. 7 bikes in a one car garage that also houses all of my tools is going to be a damn near impossible squeeze.
 
I've found that aftermarket kits don't have correctly machined pilot jets.
It's possible to modify the cross holes which are too small (as several people have noticed)
The prevalence of E10 fuels also means you must richen mixture up slightly although it's less than the 10% you would expect
 
Back
Top Bottom