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Discussion Starter · #1 · (Edited)
Ok, so I've got this CB200T in for service and have ruled out fuel issues,
as making it lean or rich has no effect (Well, no positive one anyhow)
*rebuilt the carbs
*adjusted timing
*new spark plugs
*new coil (Installed by owner)
*Cleaned points
*Tested condenser (330nf)
*Spark advance works good (Tested with timing light)
*Spark plug caps measure 5.5kOhms
*Secondary coil winding is 15.5kOhms
*Tested charging system
*Checked & tightened engine ground
*Tested stop switch, good continuity
*Tested & charged battery

Here's the interesting thing, when I totally remove the condenser, the idle gets worse but it REVS!
Maybe not as high as it should but it revs smoothly and quite high (Don't know exactly, rpm gauge doesn't work "well")

I don't understand points systems enough to know why... Anyone know?

With the Ignition Mate hooked up, it shows a drop in coil performance when it sputters, making me think that for some reason it is loosing spark.

Also, it's not the condenser itself, I actually removed the OEM one and have a diff Honda one that I was doing my tests with.
Getting the same results until I simply removed the condenser from the circuit.

Thanks in advance,
Bryan
 

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Discussion Starter · #3 · (Edited)
Got a spare battery you can hook up?
I do, I should have done that already but here's why I haven't...

I had a 150amp battery charger hooked up to the battery and was monitoring voltage and current flow into & out of
the battery before and during diagnostics and it was behaving as a good battery, nothing unusual.

No change in response with different voltages applied or with the charger disconnected.

I do have new batteries so I'll try one and post back the results.

I am leaning towards a high resistance somewhere in the ign circuit, engine stop switch or maybe a corroded connection.

I believe the running difference noticed with the condenser removed is due to less load being applied to the ign circuit.
The condenser is essentially an added load and when in the circuit, loads it down and keeps it from having
enough voltage (due to increased resistance in the circuit somewhere) to fire the coil when revved up (Increased load).

I also haven't actually monitored voltage at the coil while running so I will do that as well and post back my findings.

My diagnosis could be wrong obviously so if you know differently, please chime in. :)

Thanks,
Bryan
 

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From your description above I can't quite figure out what the running issues are or what the solve might be.
Have you tried checking wire resistance with a multimeter if you think that's the issue?
Are you testing with air box off?
Your choke open?
 

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What plugs are you using / how new ? How does the coil look ? Especially where the HT leads meet the coil body . What's the Resistance for the primary winding , is there any continuity between the primary and HT leads .With engine running if you pull one plug cap ( carefully or you'll get a zap) does the engine die , do both sides one at a time

Also leave the points cover off and see if your problem persists

Is your timing set statically or dynamic
 

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How old is the condenser (capacitor)? It may measure OK, but if it is leaking current when the points are open there will not be a full break in the voltage to the primary winding in the coil. The coil to generates full spark when the points open. Filing points are OK, but the contact surface will be rough (google RHR surface roughness) and not last. Back in the day every tune up consisted of the points and condenser.
The way a capacitor works is two plates that are separated. One has a positive charge and the other negative. The electrons are drawn together and try to move between the gap. If they touch in any place a complete circuit is formed. The are many types of capacitors. The ones in our Hondas are called paper - foil. There is a layer of foil, paper and then another foil. It is rolled up inside the metal case. If the paper degrades it can cause a high resistance across the points and the coil will not see the full voltage drop.
If I was working on bikes for money, I would make new points and condenser part of every tune up unless I knew the bike and it had resent new points and condenser.
 

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Discussion Starter · #7 ·
Thanks for the replies. :)

Unfortunately, I didn't have time today to troubleshoot further.
I will get on it Monday.

See you all then,
Bryan
 

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Discussion Starter · #8 ·
Uploaded video to YouTube.

From earlier...

Installed new battery, no change.
Bypassed all ign components and ran 12v straight to coil, no change.
Airbox is off
Choke is open (Not engaged)
HT leads look good
Primary winding is 4.8ohms
(Going to store to get new resistor caps... Report back shortly)
 

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Discussion Starter · #9 ·
Well, I had to order more caps. I didn't have any and was unable to find them locally.

Will post back later in the week.

So, reason is... I initially tested the caps and they both read 8kohms, or so I thought.
I must have got distracted and forgot to test the left one because I just did and it read 7Mohms! haha
I pulled them both off the wires and cut the wire ends but I think I mixed them up between testing and tested the same one twice.

Or at least I hope so, because that will be an easy fix if that's what it is.
And I think that's exactly what it is because I have had very similar symptoms before with jet skis. :)

Till later,
Bryan
 

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Discussion Starter · #10 · (Edited)
Update:

I found another resistor cap that measured 5kohms in my used parts bin.
Put it on, tested secondary winding lead-to-lead 25.86kOhms.
Fired it up and...
NO CHANGE! Damnit. :(

Checked timing, SPOT ON
Installed NEW plugs again (D8EA)
Applied 12v directly to the ignition coil
... Same thing... No change.

Back to square one. :/

As for the condenser, I replaced it with another one, genuine Honda.

Also, I can't pull only one plug cap off as that breaks the circuit for the other plug,
but when I use a spare plug and run on just one cylinder at a time, it runs equally worse on each individual cylinder.

edit:
I also just removed the exhaust to ensure there were no restrictions, ran it with exhaust off, same exact symptoms.
 

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Might be a dumb question but is there a reason there's no air filters on those carbs?

As I understand Hondas are tuned based on having to overcome a certain amount of restriction from the air filters. Someone more knowledgeable can tell you the exact result of no air filters, but putting them back on is worth a try especially now that that spark plug is replaced. Not sure how it would change spark breaking up though...
 

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Discussion Starter · #12 · (Edited)
Ok, so further diag...

I removed the head to check cam timing and the cam was advanced by one tooth.
It's dead nuts aligned with the T mark and parallel with the head now.
Fixed that and put new D8EA plugs in, set ign timing, and it improved quite a bit.
I can now get to redline but only with the throttle cracked ~ 1/4
Any further throttle and I only get to about 5-6k rpm.
Restricting airflow while testing only results in decreased performance, same with restricting fuel, only a change for the worse.

Strangely enough, I can't really set ign timing in the correct place now without a rough idle.
I can advance the timing about 30deg to the other two timing marks before it dies just shortly after advancing past them.
It runs best advanced about 10-15deg. It idles best advanced 15-20deg.
The auto advance mechanism works and is timed correctly (It's keyed in place).

If the owner wants me to diag further my plan is to...
Replace ignition coil, points, condenser and test.
If that doesn't fix it then with the owners approval I will tear into the motor...
I just don't know what else it could be.
I have tested it with everything disconnected today.
I disconnected EVERYTHING and just fed the ignition coil 12v and it still didn't work.
So it's gotta have something to do with the points, cam, valves, coil, timing advance*maybe... It advances about 30deg when revved up.

On a side note... What is compression supposed to be, I couldn't find it in the Honda manual.
I am getting 70 on one and 90 on the other.
It also smokes dark brown smoke from the right exhaust when I give it gas. :(

Oh, and...
I don't know how this happened but, I removed the ign coil when I pulled off the valve cover and
moved the cam one tooth. But now on my Ignition Mate, it shows WAY lower spark voltages and current.
I haven't given it much thought yet on why the change just from changing cam timing and coil removal other then
the coil was certainly not mounted correctly and was under strain on it's mount brackets.
I highly doubt it's coil related but thought I'd mention it.
The coil is a 2 wire coil so it doesn't get ground from the mount so... Hmm
Not really sure why advancing the cam timing one tooth would have that effect...
Somehow, the voltage required to overcome the ignition secondary circuit went down... Again, Hmm...
New plugs were properly gap'd... :-/

Any ideas guys?

Sorry for rambling, but you never know what piece of information might be the key. :)

Thanks,
Bryan
 

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Did you pull the engine to advance the cam a tooth? It's all ppretty tight in there between the frame and head with the one piece cam chain and all. If the top ends loose enough that you can do it with the engine in I suspect something's out of spec .the cam mark should be flat at T on the rotor , static timing ( points open ) should be F on the rotor and the other two rotor marks are for dynamic timing only
 

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Discussion Starter · #15 ·
Did you pull the engine to advance the cam a tooth? It's all ppretty tight in there between the frame and head with the one piece cam chain and all. If the top ends loose enough that you can do it with the engine in I suspect something's out of spec .the cam mark should be flat at T on the rotor , static timing ( points open ) should be F on the rotor and the other two rotor marks are for dynamic timing only
I just took out the front engine mounts allowing the engine to drop ~1/4". Was just enough to remove the valve cover.
Yea, cam is timed @ T and ign is timed @ F. Well it was, then I played around with it. But yea, it doesn't run well at any ign timing setting. :(
Since I haven't got any good ideas on here, I contacted the customer and am waiting for a reply as to weather or not he wants to sink money into points, coil & condenser.
If/when I get those components, I'll post back my findings.

Unless in the meantime I, or someone else has an AH HA moment. :)
 
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