I should start with a bit of background info. My bike previously used to run with half choke in. I had a motorcycle shop synced the carbs and i cleaned the carbs. I set the air pilot screws 2 1/2 turns out.

First thing i noticed was that as soon as i started my bike within 20 seconds running the RPM will go up to 3K or 4K, i would take the choke off a little bit so RPM would go back to 2K or 1.5K RPM.

I had to fix the choke cable as when i bring the tank down it will pull it open causing RPM to hang in 3K when in neutral and "choke" off.
I rerouted the choke cable and I'm certain it's not being opened when i put the tank down as i don't see my revs changing.

******THE PROBLEM******

RPM is increasing every time i pull the clutch when riding. It goes from 2K to 4K RPM and as long as i have the clutch in the RPM DOES NOT go down. When bike is in neutral the RPM does not increase when i pull the clutch. It's only when driving. Could it be my disk (transmission)? It makes no sense. I originally thought it was my clutch level pulling the choke cable but i had check everything i can possible think and i don't see how that could happen. I even pull my seat out and push with my finger the choke to make sure it's close before i take off but the problem still remains.

It's dangerous to ride like this as i have to press the brakes (front and read), press clutch then let go then press again then let go and repeat, repeat until i see the RPM slowly going down then i engage the clutch all the way in.


I did notice today that the RPM needle would go up and down as if there is a vacuum leak. That wasn't there before. I wonder if when i attempted to put the air box back on i connected them well.

Any ideas what could it be? I think i should open a new thread as it now seems to be going out of the original purpose of it.

********ONLINE SEARCH***************
i found this in another motorcycle forum, not a CBR forum, but i thought i'd share it with you guys for comments on whether this is something that happens to our bike

If your revs go up as the bike gets warm, if sounds to me like the clutch pushrod is out of adjustment. As the engine heats up, the case will expand and the rod will go further out of adjustment, and the clutch will slip (as if you were pulling on it part way) and the revs will go up.
The fact the revs go up when you pull in the clutch indicates further that your adjustment (rod or cable) is not in and you've raised the idle to compensate. In other words, you're clutch is always in part way and you've raised the idle to compensate.

So do this: First, back the adjustment off at the lever so you have slack on the cable. Next, find the adjustment where the cable connects to the rod. Back it out until you're sure the connection is broken then slowly push it back until it just contacts the rod. Now set the idle on the carbs (it should be high). Now set the adjustment at the lever to what you are comfortable with in terms of pull to the friction point.
It's possible your plates are worn down because of this, and replacement is a bit more of a job, put you'll notice a swampy smell if they're worn down.

If it's a vacuum leak, you can test by spraying wd-40 or carb cleaner around the carb and listening of a change of RPM when you spray close to the leak.
Also check your timing, and make sure it's not going into "advanced" timing (the timing for full chat as opposed to idle) too soon.
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PLEASE HELP

 

Part of a complete carb clean/overhaul is idle adjust with an accurate rpm guage (+/- 50rpm).
This is done after the vacuum sync.

This assures that the mechanical linkage is balanced for all four carbs.
Do a search in the how-to's, on the site.

Hope this Ern

 

Try spraying around the carbs and airbox to see if the rpm's change.

When you fit the carbs and airbox it can be very awkward the first couple of times. But when they go on properly you can 'feel' it and looking around the joints they fit perfectly. It should all fit together well, with no looseness. If you had to struggle to fit the two bolts that hold the airbox in place, then something's not seated properly.

The article you found 'on-line', is for a clutch with a cable, so I'm not sure how relevant it will be for our bikes.

 

Madhattr,
Thanks for your suggestion. I'm new at working on bikes so it takes me a while to understand.

I'm taking carb sync does not take care of the idle.
One thing i notice on my bike though, it's the fact when starting cold (Full Choke on) after 20 sec the RPM goes up to 3K and if i don't take it off it goes up to 5K in split of seconds. Once i slowly take the choke off the bike goes down accordingly. I don't take it all of otherwise it dies. Once i see it goes past the first quarter in the temp gauge i then take the choke off then it idles at 800ish RPM sometimes it dies so i just bleep the throttle to keep warming it up then idle stays steady at 1k or so; however, the RPM needle does go up and down. Someone suggested to check the air box fitting as there may be a leak.

To your suggestion, how do i go on idle adjusting? What do you mean by it? I did a search but couldn't find anything...Everything i found was related to carb sync and/or floats being flooded, which could be my case as i put the carbs back on with fuel in them. Another post was, silicone could had gone into the floats which could be my case too. I guess i need to take carbs out again.

 

Hawkwind,

Thanks for your suggestion as well. I did notice the screws to fit in the air box are difficult to put in. It seems like there is something not fitting well like you say. I will spray wd40 around the air boots to the carb.

I'm new at working on bikes, this is my first time. I don't understand, i'm please forgive my ignorance, what do yo mean our bikes does not use a cable clutch? I assume this in the inside of the casing/engine. I see a cable coming out of the clutch level, but i assume by your comment that does not mean it's like the article i found online.

Thanks

 

Here's a run-down on idle adjustment...

https://skydrive.live.com/redir.aspx...N8TPHIG_1vPihM

Hope this helps, Ern

 

Madhattr,
Thanks for the pdf! It definitely helps. It mentions a tachometer. I don't have one of this. I did an online search and found these. Would do this the trick? Or is there one specific for this bike?
Buy Sunpro Super Tach II 2 5/8" - Black Face & Black Bezel CP7906 at Advance Auto Parts

1Sunpro/2 5/8 in. 8000 RPM Super Tach II black tachometer (CP7906SW) | Tachometer | AutoZone.com

 

You need something more like this. It needs to be accurate to +/- 50rpm,
to be an effective diagnostic tool. The one's you've listed are meant to be
dash-mount general information devices, they don't have the accuracy to do the task.

Electronic Specialties Ez Tach +Plus: Automotive : Walmart.com

You will also need a specialty tool, to enable you to make the adjustments to the carb-bodies.
Something similar to this...

Pilot Screw Adj. Tool | Motion Pro

Ern



Ern

 

Thanks Madhattr!!!

I'm going to check with my local motorcycle shop to see if they have the tools you recommended.

I purchase the motion pro 90degree tool but it did not work in my bike as the tool itself was too wide to fit in between carb two and the throttle end (between carb 2&3) so i returned it. Now this one, in the pic seems thinner and it's 110 degree so hopefully i can fit in between the carbs. Unless i'm trying to do it from the wrong side.

Thanks again for your help. I can't wait to get this figure out and ride.

 

Just be sure you have the skills to use the equipment.
It can often be cheaper to pay a professional than to purchase a bunch
of specialty tools that you will only use every 3-4 years.

Especially if you don't fix the problem.
The advantage to a pro is their diagnostic expertise.
They will avoid applying 5 fixes to a one fix issue.

I don't discourage DIY, just be sure you can DIY.

Good luck, Ern