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Discussion Starter · #1 ·
So we picked up this CB450 over the weekend. The plan is to refurbish the electrics and get her running properly. The previous owned complained about a possible fueling issue, so we'll take a look at that, too.


First step is to strip the old electrics and replace them all with new parts.


The old separate rectifier and regulator have been replaced with a Sparck Moto unit.


We're also in the process of working on Honda 450 harness recreations, so a sample harness is replacing the old crusty one. Unfortunately, our manufacturer didn't have all of the OEM colors available (yet) and so they substituted white for almost everything! Good thing we know our way around a multimeter.


Finally, the old coils looked like they were approaching the end of their natural lifespan and so a new set of specially made 4.0Ω coils are going on in place. We're expecting to have these ready for sale late in the summer (or maybe mid-autumn) if they perform well.

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Nice one! I'm thinking stock coils are 5 ohm and 4 should give a stronger spark and better performance?
 

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Yeah I saw you posted this on instagram. Nice survivor indeed.
 

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Nice find, glad to see it made it into good hands! I like the prospect of your offering of coils, please keep us updated on the availability of those as well as the work on this 450
 

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Counting on you to make a quality unit for this situation, Matt... (in light of all the discussion you surely have seen here about others) :D
 

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Installed the prototype of our E-Sparck electronic ignition. We're planning to release these for the 350, 360, and 450/500 to start. Hopefully I can get things buttoned up and running so I can put some miles on and verify that all is good.

View attachment 284134

I'd like to know more about this EI.
 

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Discussion Starter · #10 ·
I'd like to know more about this EI.
We've gone with a simple unit to begin with. My preference is to start simple, make sure it works, then increase complexity if it's warranted.

Cast aluminum is used for the backing plate as well as the cylinder that replaces the points cam. Magnets are embedded into the cylinder and those trigger Hall effect sensors which are epoxy potted in the black plastic casings you see. A little bit of wiggle room exists on the mounts for the sensors so that you can fine-tune each cylinder's timing independently.

The mechanical advancer is retained for two reasons:
1.) Primarily, it helps keep the electronic complexity to a minimum, as well as the cost.
2.) My 360 runs on non-standard timing, which I've accomplished by modifying the advancer I wanted this unit to work on my 360 as well. ;)

If we end up making our money back on this one, a unit with an electronic advance is foreseeable. Possibly even with tachometer outputs and a programmable curve.
 

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Simplicity is often times the best and something I think many products have missed the mark on.

I am a firm believer in the KISS principle.
 

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I'll be watching, Matt - I'm sure there will be no comparison to the most recent "trial" product, which had trials of its own
 

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Could be carbs need synching. I assumed you already checked ignition timing.
 

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^^^agreed. I'm wondering if the pilot passages in that side's carb are completely clean... the little "sput" sounded like some I've seen on one that you couldn't get adjusted quite right because they were still a bit gummed up. Man, talk about patina... the tank is almost basecoat silver on top! What a great find you have, Matt :D
 

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Turn the idle down and see how it behaves. If it's an intermittent but semi-regular cough on one side when idling around 1,000-1,100rpm that disappears under load (like 3k+), the first place I'd check is the little springs on the spark advancer mechanism (from what you've said, I'm assuming your ignition unit still uses the advancer mechanism with a different cam piece). Those symptoms suggest one of the springs has slackened to the point where the bob weight will occasionally kick out, causing the cough.

I say it's the first place I'd look because it took me eight years to work that one out. It's also why I ended up going with an ignition unit that does away with that mechanism entirely . . . and obvs ignore all this if yours removes them, too.
 

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Discussion Starter · #19 ·
Turn the idle down and see how it behaves. If it's an intermittent but semi-regular cough on one side when idling around 1,000-1,100rpm that disappears under load (like 3k+), the first place I'd check is the little springs on the spark advancer mechanism (from what you've said, I'm assuming your ignition unit still uses the advancer mechanism with a different cam piece). Those symptoms suggest one of the springs has slackened to the point where the bob weight will occasionally kick out, causing the cough.

I say it's the first place I'd look because it took me eight years to work that one out. It's also why I ended up going with an ignition unit that does away with that mechanism entirely . . . and obvs ignore all this if yours removes them, too.
I'm definitely not ruling out carb issues, but this sounds like something I definitely need to check out. According to the tach, I'm idling at around 1200 RPM and the ignition is already starting to advance. That seems a little early, so spring tension could be compromised.
 

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Discussion Starter · #20 ·
I pulled the carbs off and found a few interesting tidbits.


1.) The petcock was only flowing fuel through one of the spigots and so the left side was definitely underfed.
2.) There was a slight gap between the manifold and the head on the left side as well (a bit of Threebond cleared that up).


That carbs appeared to be in mostly good condition, but I cleaned them up and replaced most of the brass (the rebuild kit had the wrong style mixture screws, so those old ones were reused).

Float heights are set at 20mm and the carbs are ready to go back on.

Also, the main jet in the kit was a 145, but the ones I pulled from the carbs were 130s. I swapped in the larger size and we'll see how it goes.

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