This winter I did a lot of work, installed 49 state cams, did the valve adjustments, removed the smog stuff, and sync'd the carbs.

The bike starts and idles fine, and revs okay too. Under a load the bike starts bucking at about 6k rpm, and will NOT rev past 7k rpm.

I feel I got some lame advice on the smog stuff regarding what to plug and what to leave vented.... I just tried unplugging the one thing I plugged, and it still didn't work.

I am unsure what to try now. I could try plugging more stuff in hopes that will work, but I hate guessing.... No other changes were made, bike is all stock, stock jetting, stock pipe. Ran great when I parked it for the refresh...

P.S. I also changed the coils out for a CBR600RR coil-on-plug system... I suppose a last ditch effort would be to swap back to the original coils... I knew I shouldn't have changed more than one thing at a time, but I was excited.


Can anyone offer useful, mechanical advice on this? Things I may check? I have a full tank of gas and the petcock works....


Here is the video of the problem:
http://www.youtube.com/watch?v=HTmHcrhFyMQ

James

 

Okay, here is what I have done:

Removed Ebay coils, installed original working coils. Same problem exists.

Tested fuel pump flow by pumping fuel into a measuring cup for 5 seconds per the manual. It pumped nearly 4oz in a little more than 5 seconds, which is to spec.


I installed 49 state cams only, just as I said above. The ECUs are the same for both 49 state and Cali of this year. The carbs are different but only because of some spare hoses and things. There is also a Slow Air Idle Jet in the Cali carbs...

I am tempted to check the main jets to see if they are clogged, but I figured the pilots would clog first...


James

 

Ya.... If this were one of my quads that would be easy. I suppose I could run it towards the garage and coast in. The plugs just aren't like the ones on a 250R, easy to get to....

I just checked the main jet in cylinder #1's carb. It is size 115, and it was clear... sigh.... What the heck!

 

Just checked the sparkplugs, they were all snug. I gave them all a final grunt. Let the bike warm up and revved it... Still the same problem.

Running out of stupid stuff to check.... !!

James

 

The bike is totally, 100% stock. The mains, the pipe, the filter is OEM Honda, everything. The only thing not stock so far is the 520 conversion I just did. Everything should work just fine.

Here is what I did:

49 state cams
valve adjustment
iinstalled 600RR stick coils
removed charcoal canister and check valves (PAIR system)
blocked off PAIR outlets above exhaust headers
carbs sync'd


What I have checked:

swapped in OEM coils
tested fuel pump output
checked #1 main jet
tightened spark plugs

Aside from what I said above, there is a chance that when I was changing the cams out the cam chain slipped a tooth on the crank sprocket..... I don't really want to think about that right now though.....


James

 

You took the words right out of my mouth. That is the only thing left I can think of. Although, I have never seen a California emissions bike, so I don't know what else is involved in that system.

 

Okay... Checked a few more things.

-Swapped coil wires, no start. Swapped them back, starts and idles.
-Sprayed headers after bike was warm. The sizzling all seemed the same. It sounds like it is running on all 4, very smooth.
-Checked 3 out of 4 main jets. All are fine.


Three things left to tell everyone:

-I was just revving the heck out of it, and it finally felt like it started to clear out, and went to redline. Stumbles a bit on the way up, but it was taching to 12k...
-I tried adding choke, no change really...
-I watch the diaphrams open, they seem to shudder as the open up... all four of them. Is that normal, or should the opening be smooth? They all rise up together as I rev it, but they look like they are trembling as they rise...


I talked to a friend about the cam chain, and it should be fine. The crank never turned, so it doesn't matter what the chain did as long as the cams were set in and aligned properly.

James

 

Glad you finally got it working right.

If it's still not 100% you can always get it checked at a Honda dealership, just to make sure everything is at factory specs.

I don't have anywhere close to the mechanics ability you have, so that is my advice.

 

just a thot.. are you sure that the petcock is working correctly? maybe there is not enough vacumme to open petcock fully(wood explain not reving all the way) this wood explain normal idle but not the revs .and yes it is normal for the shutter to flutter thru the revs.JMO good luck bro

 

Well... I can tell you that the only progress I saw was yanking the bowls and checking the main jets. I believe the jarring of the float bowls helped. After that is when it finally started revving on out last night.

Today I pulled the carb bank off to go through carb #4. After doing that I noticed a crack in carb #1's intake boot connecting the carb to the cylinder head. I don't know if I caused that today by pulling the carb bank off, or whether it was there before. So, tomorrow I am ordering new boots. I don't want to take a chance on that boot sucking air.

I will give you a full report next week when I get the parts in...


By the way, I have a 1994 model, which does not have a vaccuum operated petcock.

James