Topic: How much timing is too much? CB550

[cb550fcafe]

The tuning saga continues. So with the exception of a slight sputter,hesitiation when cracking the throttle off idle from a stop, my bike runs super. I know absolutely for sure I'm too rich. So at this point, I'm getting tired of pulling carbs off, rejetting, moving clips, syncing again to road test and find one problem solved, another shows up.

So, with my current state of tune, I found that if I advance the base timing (using a timing light) 5 degrees, the motor is perfect. However I am nervous about running too much timing on the higher rpm areas.

So, my second fix instead of base timing advance, I removed one spring from my advancer so the advance comes in quick, result is no stumble, runs great.

In the end what is probably the best of the worst fix. I can't find a comprimise within the carb to give me the best rideablility, so i have to run a bit rich, which requires a little more timing. Just looking for some reassurance or spankin.

[Gordon]

If you don't have carbs with an accelerator pump, you will always have hesitation when cracking open the throttle from idle.  That's just the way they work. 

With only one spring on the advancer, you're probably getting close to full advance at just idle speeds.  I highly recommend doing what Hondaman suggests in "The Thoughts of Hondaman" in the FAQ section:

Set the timing 5 degrees advanced (which you've already done) and cut off one coil from each advancer spring.  This mod alone made a noticeable difference in how well my 550 runs.  Also, replace the paper air filter with a stock replacement oiled foam filter, and open up the air intake by 25%.   

[FunJimmy]

Gordon

Good advise, but do you have a photo of the opened intake?

Thanks
FJ

[Gordon]

Gordon

Good advise, but do you have a photo of the opened intake?

Thanks
FJ

Sounds more technical than it actually is.  I just drilled about 20 small holes in the plastic filter cover/tool tray that sits under the seat and on top of the air filter housing. 

[cb550fcafe]

I highly recommend doing what Hondaman suggests in "The Thoughts of Hondaman" in the FAQ section:

Set the timing 5 degrees advanced (which you've already done) and cut off one coil from each advancer spring.  This mod alone made a noticeable difference in how well my 550 runs.  Also, replace the paper air filter with a stock replacement oiled foam filter, and open up the air intake by 25%.   

Thanks! Great info and it reassures me that I am going in the right direction. I'm on my way home to mod those springs now.

[B.O.X.N.I.F.E.]

Isn't this ignition timing? I thought the hondaman thread suggested advancing the cam timing 5 degrees.

[Flying J]

when you move the needle clips how far do you have to take your carbs apart? Is there a quick way to do it or do you have to take the whole rack apart?

[Gordon]

Isn't this ignition timing? I thought the hondaman thread suggested advancing the cam timing 5 degrees.

I was off.  Hondaman's suggestion for ignition timing is for 2 degrees of advance, not 5. 

His suggestion for the cam is to get a longer duration cam and advance it 3-4 degrees, but I haven't gotten into the more in-depth mods he suggests for the 550 yet. 

[B.O.X.N.I.F.E.]

Isn't this ignition timing? I thought the hondaman thread suggested advancing the cam timing 5 degrees.

I was off.  Hondaman's suggestion for ignition timing is for 2 degrees of advance, not 5. 

His suggestion for the cam is to get a longer duration cam and advance it 3-4 degrees, but I haven't gotten into the more in-depth mods he suggests for the 550 yet. 

I've got a 650 cam for mine and thought about doing a small advance on it. Never done it on a bike so I'll do a post when I start the install.

[FunJimmy]

when you move the needle clips how far do you have to take your carbs apart? Is there a quick way to do it or do you have to take the whole rack apart?

Download the manual and you should be able to remove the slide in each carb (one at a time) to access the needle.
You shouldn't have to separate the carbs from the rack.

[mlinder]

Isn't this ignition timing? I thought the hondaman thread suggested advancing the cam timing 5 degrees.

I was off.  Hondaman's suggestion for ignition timing is for 2 degrees of advance, not 5. 

His suggestion for the cam is to get a longer duration cam and advance it 3-4 degrees, but I haven't gotten into the more in-depth mods he suggests for the 550 yet. 

I've got a 650 cam for mine and thought about doing a small advance on it. Never done it on a bike so I'll do a post when I start the install.

You'll need to have the cam gear slotted to do so. Machinist can do it for a couple bucks.

[B.O.X.N.I.F.E.]

Isn't this ignition timing? I thought the hondaman thread suggested advancing the cam timing 5 degrees.

I was off.  Hondaman's suggestion for ignition timing is for 2 degrees of advance, not 5. 

His suggestion for the cam is to get a longer duration cam and advance it 3-4 degrees, but I haven't gotten into the more in-depth mods he suggests for the 550 yet. 

I've got a 650 cam for mine and thought about doing a small advance on it. Never done it on a bike so I'll do a post when I start the install.

You'll need to have the cam gear slotted to do so. Machinist can do it for a couple bucks.

Yeah, I was just reading about that last night. Doing a bike cam will be a new experience. We're hijacking this guys thread, I'll get one started if I degree this 650 stick.