Black and Gold Cafe - 71 CB350

[Korsch_RS]

Re: Black and Gold Cafe - 71 CB350 - VM30's!

Well, I got the replacement transistors yesterday, and soldered them on without any problems. I mounted the old circuits to the board, and then cutoff the old transistor. I did this do I would know for sure that everything was oriented correctly. Then is was simply a matter of tweaking the new transistor leads a little bit (shortening and bending) so they laid on top of the cut leads, then apply a little flux, some heat and solder, repeat for the other transistor, and ta-da, finished.

Reinstalled on the bike, and she started up with the VM30's enricher valves open. Didn't run it or do any timing adjustments as it was getting late, so that will come today, and hopefully a test ride if the the weather man is wrong (predicting some rain showers this afternoon/evening)

Pics!

More soon!

 

[Korsch_RS]

Re: Black and Gold Cafe - 71 CB350 - VM30's!

Finally!! It's running and riding well!!

I got the new ignition on and after getting it timed I was able to get the idle to settle down. I actually had to trim the base plate in order for it to be advanced enough, it appeared that the cut-outs were in the wrong spot from PAMCO, oh well.

I'm only getting high 30's mpg, so it's definitely still too rich. Better that than too lean though!

More soon!

 

[axeugene27]

Re: Black and Gold Cafe - 71 CB350 - VM30's!

what jets you have in em right now.

 

[teazer]

Re: Black and Gold Cafe - 71 CB350 - VM30's!

Nice catch on the Pamco and nice repair. So often the OP says, I checked the timing and fitted a XYZ ignition, so I know that isn't the issue. It always pays to double check.

When those throttle cables brake - I mean IF - go to Flanderscables.com. They have all the parts you need in whatever wire gauge you want.

 

[Korsch_RS]

Re: Black and Gold Cafe - 71 CB350 - VM30's!

what jets you have in em right now.

Current Carb settings (only idle tuning has been done):
pilot 25
air jet 2.0
air screw: 1.25 turns out
Slides 2.5
Needle 6F4
Needle clip 4 (1 lean, 5 rich)
needle jet P-0
Main 150

Current running issues:
low mileage
slight smoke on heavy throttle (according to friend riding behind me, don't know if it's a puff or continuous)
doesn't like to sit at one rpm, kinda sputters a little bit, but if I crack the throttle open even the slightest amount it pulls cleanly (but slowly, i mean, it does only have 36hp)
Waaaaaaaay too loud, I'll fiddle with the jetting after I get some baffles in the exhaust to quiet it down

And these are the extras I have right now:
Mains: 110-200
Pilots: 10-30, 45-50
3.0 slides
6F5 needles
P-5 needle jets

Nice catch on the Pamco and nice repair. So often the OP says, I checked the timing and fitted a XYZ ignition, so I know that isn't the issue. It always pays to double check.

When those throttle cables brake - I mean IF - go to Flanderscables.com. They have all the parts you need in whatever wire gauge you want.

Thanks! Looking back with 20/20 hindsight it makes perfect sense. Bike was running good, intermittent issues (usually electrical), lots of dust under the timing cover. makes sense that it was the ignition. Luckily I remembered enough from my college circuits class to go through the system and diagnose each component piece by piece and isolate the problem. It did take a little chatting with some of the electrical engineers at work about the inner workings of IGBT transistors to make sure I was on the right track though. And then when I saw how cheap the transistors were it made complete sense to try and fix it. I got three (1 extra) of the same part number shipped to my door for $18.

I'm really happy with the throttle setup now. It's super smooth and snaps back closed very quickly, and with the carb adjusters and also in-line adjusters it's got plenty of flexibility. Also the barrels on the twist grip end were cast? on the cables properly from the bike shop, so no worries about them. I'm not super happy with the fittings on the carb ends though. I couldn't get solder to stick on these cables for the life of me (i could on other cables though, go figure), so right now I have crimped electrical fittings. I'll be looking at that website for something better for the carb end. Thanks!

 

[axeugene27]

Re: Black and Gold Cafe - 71 CB350 - VM30's!

i've got 145 mains in and the needle clip on the leanest setting pulls hard all the way through esp on the top end

 

[Korsch_RS]

Re: Black and Gold Cafe - 71 CB350 - VM30's!

i've got 145 mains in and the needle clip on the leanest setting pulls hard all the way through esp on the top end

Are yours set up exactly the same otherwise? What exhaust are you running?

 

[jerryz]

Have the same bike, but just starting out with getting it going. Really enjoyed reading this thread. Thanks for all of the very detailed posts!

 

[axeugene27]

korsch i have a stock exhaust on it right now. Over the winter i Intend on going with a shorter one so may changeup the settings. I have pretty much the same exact same set up except I put the needle clip to the leanest settingI also have 2.5 cutaways P-5 needle jet. Pulls much more uniform now. I rode110 miles yesterday and didn't even use half a tank. My only problem with my current setup is once the bike is started i have to let it warm or else when i touch the throttle the bike dies. Once warm it responds very well to throttle. I Think i may go back to a 30 pilot and see what happens.

 

[Korsch_RS]

Have the same bike, but just starting out with getting it going. Really enjoyed reading this thread. Thanks for all of the very detailed posts!

Glad you enjoyed it! There's a ton of info floating around this site so you're in the right place!

korsch i have a stock exhaust on it right now. Over the winter i Intend on going with a shorter one so may changeup the settings. I have pretty much the same exact same set up except I put the needle clip to the leanest settingI also have 2.5 cutaways P-5 needle jet. Pulls much more uniform now. I rode110 miles yesterday and didn't even use half a tank. My only problem with my current setup is once the bike is started i have to let it warm or else when i touch the throttle the bike dies. Once warm it responds very well to throttle. I Think i may go back to a 30 pilot and see what happens.

I leaned out the needles 2 positions Saturday and also built a baffle for my exhaust (it was ridiculously loud). Put about 80 miles or so on it this weekend and getting better mileage, mid 40's now. Also reportedly less smoke out the back on heavy throttle. Mine dies if I touch the throttle when it's cold too.

Current Carb settings:
pilot 25
air jet 2.0
air screw: 1.25 turns out
Slides 2.5
Needle 6F4
Needle clip 2 (1 lean, 5 rich)
needle jet P-0
Main 150

 

[Korsch_RS]

Been doing some more carb fiddling. Going to the 30 pilots helped my off-idle stumble (but it still will a little when cold, but much better). I was also chasing all sorts of idling issues. When it was cold it would idle rock steady at 1500, then once warmed up it couldn't idle at all. Turns out one of the carb boots that came with my VM30's was ripped and leaking, so I used the newer stock ones. I think these will work better in the long run anyway as they are much stiffer and hold the carbs much steadier than the vm30 ones. I found this after putting the 30 pilots, so I was chainsg myself in a circle, as once the leaks were fixed the idle was all screwed up. I had to raise the slides significantly to get it to idle again (makes sense as it was getting extra air through the leak). I also tried raising the needle a notch to help the stumble. I'm not sure if the stumble was fixed by the needle or the pilot, so I'll try lowering the needle again sometime and see what happens.

Anyway, current settings:
pilot 30
air jet 2.0
air screw: 1.75 turns out
Slides 2.5
Needle 6F4
Needle clip 3 (1 lean, 5 rich)
needle jet P-0
Main 150

 

[Tremelune]

Those black fasteners are the business. Would you mind sharing where you got them from so that I may copy you for my own build?