Topic: CB650 **Urgent** I think cylinders 3 and 4 are not firing!!!

[checkflag]

Couple more Videos.

1st.. a daytime shot of the one exhaust putting out exessive fumage, while the other does nothing.

Second, This video shows the erratic behaviour of the idle speed. Notice
I adjust it down, I touch the throttle and it stays at 3k rpm, then it cuts it's own power
with a "clunky" sound

During the day today, A funny thing happened. The 3/4 exhaust Popped a few times with a puff
of smoke and kinda backfired along with the "pop"

NOTE :: I added a few ounces of Seafoam in both the Fuel and the Oil.

[manjisann]

The seafoam in the oil is only supposed to be done right before an oil change, it is meant to help dislodge any buildup. I don't believe it is meant to be a permanent additive.

I'm not able to view the video at the moment as I am at work. The idle sticking high after throttleing sounds like an air leak between the carbs and the intake on the engine. Take some starter fluid, or carb cleaner and spray the boots one at a time where they seal against either the carb or the engine. If the engine rpms change you have found the guilty boot, and with luck only need to tighten down the band.

Brandon

[checkflag]

Hi Brandon.. thanks. Since this bike sat for 25 years, crud has
made a presence inside the engine. B4 I bought it they guy
put in fresh oil, but i figured to only use that oil for a few hundred
miles and change it anyway. I will do that soon.. Im going to ride
some today, and later change oil.

im also going to try that carb test to.. ill let u know how that goes.

Kyle

PS.. did you get that stuff sent out today   ?

[the technological J]

i had the same problem it was a mix of an air leak and out of time bike and un synched carbs.. i now get better gas milage and when i fixed the timing it stayed at the high idle and i just unscrewed it back to the low(proper) idle... I had to take the intake  manifolds off and put a copper gasket seal on the old gaskets and it fixed the air leak... good luck

[manjisann]

PM'd you with the tracking number. Don't worry if it comes up invalid, for some reason the other shippment I sent is coming up that way, if for some reason they don't get there wed afternoon I'll be happy to call UPS and get it tracked.

As far as running the Seafoam in the oil, I wouldn't ride her too hard, remember the seafoam thins the oil out and these bikes like to leak around the seams. That is just my thoughts on it.

Brandon

[Hush]

Watching the videos you may have an over oil problem but your carbs are definately out of sync.
That's why they pop and stall, one is getting heaps of gas and trying to run at 3000rpm and one is getting stuff all gas and is so lean it is trying to stall.
Eventually the mix gets so bad it will stall out.

[checkflag]

and today.. a whole new can of worms.. Electrical. 

A day or 3 ago I did the simple multimeter test to see if the battery
was charging. It was.. 14.5v under throttle. So i was relieved considering
the things I hear about the 650's charging pitfalls. Yesterday, like an idiot,
I left the power on w/ out the engine running and drained the battery.

I jumped with cables from my cars battery.. OK, but if I took the leads off
the battery, it would shut off. So , I let the cables sit for a while with
the car running, but the bike not. after 45 minutes she started up and stayed
running. Yay.

today i go to pep-boys and when i go to leave, it wont start. I end up buying a
1amp 12v charger and push the 500lb'er home about a 1/2 mile. (maybe less)

after 4 hours of charging.. she starts, no problem, but i checked the voltage
and under throttle it's reading 11.76. boo. no charge.

I read some threads about charging, but I am such a lay-man with electrical
i dont understand any of it. Like a child, I need pictures or videos on how to test
ohms, resistance, anything but voltage. Do i need motor on, or off.. power but no motor..

some people said .. "test like this.. blah blah blah.. " but after they go into details im lost.

[manjisann]

Check to make sure you didn't boil the water below the low line. If you did fill the cell with distilled water, do not use any other type of water, the minerals in the water will short the cell. When I left my lights on all day my battery never did recover, but it was fairly old. At the time I was selling the bike and I needed a good live battery, so I just went to walmart and bought one of theres. My only complaint is the stupid sides are hard to see through to check the fluid height. You can try putting the trickle charger on the battery overnight and see if that helps, if not the battery may just be toast. I'm not a battery expert, so I could very well be wrong on this.

Brandon

[checkflag]

trickle charger worked fine.. charged over night.. now have a good battery.., However,
The battery still not charging when revving engine.

multimeter readings..

3 Stator yellow wires.. all 0.5ohm

rd/wht  to yellow with ground on red, 5.55ohm
grn to yellow with ground on yellow, 5.2ohm

All other tests betwnn thes wires, forward or reverse, no reading at all

I am just hoping i did something wrong in readings, but its more ikely something is broke.

[Hush]

Battery will only charge once you go past 3000 rpm, under that it is discharging. (even when idling)
Once the charge gets to around 14 volts the regulator cuts in and drops the amount of charge going to the battery so you don't fry it.
If your bike is running and starting OK don't worry too much about all those readings, sounds like you discharged the battery and now it is charged again you should be right.
Hey if I'm wrong you wont need to go to the gym for a while as all that pushing will be great for the legs, lungs, heart etc.

[checkflag]

Update..

I just added a MAC exhaust.. nonetheless.. I did a Ppug chop tosay to see what was going on in there..
and my motor is all over the place. The pics :

Plug 1.. Looks real hot, and it is.. this is the hottest pipe when running.


Plug 2.. FOULED ! WTF. I thought this one was hot too.. the header pipe is.. (maybe cause its
so close to 1)


Plug 3.. Also looks hot.. But this is one I suspect isn't firing much. who knows. It has one little
black spot on the ceramic.


Plug 4. Dark, wet fouled I have no idea whats going on in there.. Hondaman.. take me away>>>!

[Hush]

Carb sync required big time, they are all doing different things, typical of unbalanced carbs.
Cost me $130 for my carb sync last week, what's one cost in USA?

[checkflag]

Carb sync required big time, they are all doing different things, typical of unbalanced
carbs.Cost me $130 for my carb sync last week, what's one cost in USA?

When I bought it the guy I bought it from said he cleaned the carbs and synched them.
He even showed me the synchro pressure guages he used. I dont know because I was
not here to see what he did. Another that was mentioned was that there could be
something wrong in with a valve or 2.

Remember, she sat un-used for 25 years or so. Arrgh.. this is kind of annoying. 

[Hush]

Maybe he misunderstood what we mean by synchronising carbs, also how good was he with his own carb vacuum set?
It cannot hurt to recheck the valve gaps either, at least you will be able to delete them as part of the problem.
But with plugs like that you have a definate error in mixture or supply of some sort.
None of those look right to me?

[manjisann]

Have YOU done a full tune up from beginning to end? I can tell you from experience TwoTired would say that is the first step in trying to figure this out. There is no disrespect meant toward the PO, but you have no idea how competent he was with his equipment, and as Hush has pointed out it looks like there may be more than one factor at play here.

To do a full tune up the only really expensive tool is the Carb Vac Sync, it can range anywhere from approx $70 on up.

http://www.z1enterprises.com/detail.aspx?ID=2727

This is the one I purchases and I couldn't believe what a difference it made once I synced my carbs. Prior to that I couldn't get my bike to idle reliably below 1800 rpms. After doing the full tune and syncing the carbs she would idle like a top at 1100 rpms once warmed up. And especially where you just changed exhaust types your carbs are gonna be totally out of whack.

Brandon

[checkflag]

Did a valve adjustment today, ok.

What was learned? Well cylinder 4 is not
firing. It's got compression, gets fuel, gets spark
but does not fire.

We are still working on it, but if
anyone has had experience with this
please chime in. 

[manjisann]

If you don't have one already, but the Clymer manual. We all malign it, but it does have its useful points such as walking ya through a basic tune up.

For now I found this in the Manual FAQ, didn't study it real close but I think it gives you the general info.

http://cosky0.tripod.com/id3.html

If you have the holy trifecta of motorcycle engine running, compression, fuel and spark, it should run, assuming it is tuned properly. If it is not, you will just be filling your tail pipe with fuel. I would seriously advise a full tuneup at least to the carb sync part if you don't have a sync tool. That will ensure your timeing is correct and that spark is being delivered to the right cyliners at the right time. Until this is done, you will most likely be chasing ghosts. I'm sure this isn't what you wanted to hear, but can promise you that unless you luck out and find the thing that is misadjusted, you'll spend a lot of time chasing your tale.

Brandon

[checkflag]

Correction.. it wasn't getting fuel from the carb.. I am so damn pissed now..

[Bill/BentON Racing]

You need to service bike ,check compression if possible,then you will probably need to clean your carbs,mechanically sync them and see what you have,reg/rectifier should be checked.Bill

[Hush]

There Brandon, the trifecta was missing one ingredient.
Gas-air-compression-timing............should run.

[Bill/BentON Racing]

All three ,It Better Run! Bill

[manjisann]

Hush, I don't know how they count on the otherside of the globe, but thats four, so it would be a quadfecta, which just sounds silly 

Brandon

[Hush]

Kind of ruins the fire triangle they teach us at fire fighting training eh!
I guess compression is the one we add.