A little surprise for me... and a question for you...

Posted: Tue Jan 28, 2014 1:36 am

Guys,

I had a chance to be in the shop over the past weekend and I started one of my winter projects - removing the carbs for the 900F for a good cleaning.

I decided last summer that the carbs needed to come off because the engine just wasn't running as good as it should be. The engine always had a stumble to it just as I started to open up the throttle. This past summer, it just never ran well. especially in the middle RPMs. It seemed that the engine always wanted to be choked.

So, I go to the 900, took the seat off, the tank off and started getting ready to get to the carbs. I loosened all of the clamps around the air intakes and the insulator boots. I was ready to move the airbox back, so I removed the air cleaner filter cover and behold my surprise.

An airbox full of bird seed! I only wish I would have thought to grab a picture of the seed, but I didn't. Here's the box after being cleaned:

The seed was up to the bottom of the filter. No, I didn't find any mice, although I expected to find them.

I know that this seed was in the airbox *all last summer*! I know this because that's the last time I brought bird seed home (I keep it in my garage/shop area). I know this because I *didn't* bother to check my air cleaner last spring before riding season! I'll never do that again!

Could this debris in the airbox be causing my poor rideability? The filter should keep the seeds in the airbox and out of the carbs, but had I known, I never would have let that happen.

So now the carbs are off and this is what the carb outlets look like:

Do you see the distinct trail of tan 'scum' at the bottom of the carb throat? I pushed at it with my fingernail and it wipes away with not much effort. I haven't opened up the carbs to see what the bowls look like, but I will shortly.

Certainly looks like a good cleaning is in order. These carbs were completely rebuilt with new seals two riding seasons ago.

Any suggestions as to what is order to get these working properly again? I know I need to get each jet out to make sure they are clear and clean. I'll report back with some picture of what they look like inside once I get the bowls off.

Scott (will always check the airbox on each bike before the new riding season!)

Posted: Tue Jan 28, 2014 1:57 am

I had a mouse nest one spring. I shove a rag in the intake now each fall. Was it black sunflower seeds or thistle?

Posted: Tue Jan 28, 2014 2:23 am

Been there,

Posted: Tue Jan 28, 2014 2:27 am

CBX,

I regret not getting a picture, but yours is on the money.

My mouse (or mice) were particular. They just carried the small round seeds into the airbox. No sunflower seeds whatsoever.

I am still wondering if any of the seed dust made its way past the filter to pollute the carbs. I'd like to know what the tan crud is.

Scott

Posted: Tue Jan 28, 2014 2:30 am

Sure the bird seeds could have caused the poor running.
Air flow would have been "choked".
May not need a complete carb teardown.
Once had acorns stuffed in the end of a muffler. Squirrels are my enemy.

Posted: Tue Jan 28, 2014 2:37 am

There off, at least clean the easy parts before you put them back on.

My 2 cents

Peace, Jim

Posted: Tue Jan 28, 2014 3:28 am

JJam wrote:

There off, at least clean the easy parts before you put them back on.

My 2 cents

Peace, Jim

What Jammer said... I would definitely verify, that the SLOW JET ports and the PRIMARY MAIN ports are cleared.. And check that your Air Cut off assembly are not torn..

Also, did you replace the butterfly plate screws with these BIG, airflow disrupting, socket cap screws? For me, I would not use those.

Posted: Tue Jan 28, 2014 4:02 am

I dont think those are the proper screws in the throttle blades. Those hex drive heads are enormous and directly in the air flow. It'd be easy for me to believe they'd disturb air flow over the primary circuits enough to cause a drive-ability issue. I think Id try to source the correct phillips head screws.

Posted: Tue Jan 28, 2014 4:04 am

melchiro wrote:

JJam wrote:

There off, at least clean the easy parts before you put them back on.

My 2 cents

Peace, Jim

What Jammer said... I would definitely verify, that the SLOW JET ports and the PRIMARY MAIN ports are cleared.. And check that your Air Cut off assembly are not torn..

Also, did you replace the butterfly plate screws with these BIG, airflow disrupting, socket cap screws? For me, I would not use those.

+2...spray em' out with carb clean (Berryman's) and the red straw tapered down at the end....do the slow jet and primary as stated....and the air bleeds as well.....

Jebby

Jebby

Posted: Tue Jan 28, 2014 2:12 pm

All that yellowie stuff is fuel residue and caused by fuel "stand-off". You can actually see the airflow in the carb by what's clean and what's not.
Since someone has replaced the hardware with the wrong stuff, (the 2 screws side by side aren't even the same in #1) this indicates to me that they didn't know what they were doing with regards to CV carburetors or carbs in general.
Don't trust any of the jet sizes or needle settings (look for shims). They may have been set up for pods and could have been drilled. Don't rely on what's stamped on the jet. They should be measured to verify their size.
If this is over your head too, send them to a qualified professional (like Mike Nixon or myself) that can sort these out for you. Know when to "tag out".
Replace the connector boots as well.

I use and highly recommend Randakk's kits, with Viton o-rings and bowl seals.

Regards,
J.R.
CBX-tras LLC

Posted: Tue Jan 28, 2014 7:48 pm

where the hell are you guys storing your bikes?

Posted: Wed Jan 29, 2014 2:13 am

CBX,

Thanks for the reply. That's what I am trying to learn.

The yellow stuff... that's 'normal' fuel residue or was it worsened by the fact that I rode the bike last summer with an airbox full of seed? Keep in mind that I probably logged only 3 to 4 hundred miles on this bike last summer (I assume only a fraction of what most normal riders put on their bikes). Also, I don't know what you mean by the term 'fuel standoff'. What causes it? The incorrect hardware?

I did use the Randakk kit when I went through my 1100F carburetors. I agree, that's a great rebuild kit. I didn't know about the Randakk kits when I worked on the 900.

Like most things in my life, I live and I learn and I enjoy the process. When I learn and do a better job of setting up these carbs, I'll be able to enjoy the bike even more.

I appreciate the help.

Moto,

Bike storage... Yeah, just in my garage / shop area. My garage stays warm enough for me to work out there, so I imagine the mice appreciate that as well!. The winter we are having this year has kept the mice out of my sight - They must be hibernating! The past winter (when, I believe some critter was busy storing food in my 900) was one of the worst I've experienced for mice. I killed 20 of them before I got tired of dealing with them. I can only imagine how many went past my traps after one of their buddies already set it off! I live in the country and I've often joked that I share my house with many families of mice. It's just a fact of living in the country.

Scott

Posted: Wed Jan 29, 2014 4:10 am

sbparks wrote:

Moto,

Bike storage... Yeah, just in my garage / shop area. My garage stays warm enough for me to work out there, so I imagine the mice appreciate that as well!. The winter we are having this year has kept the mice out of my sight - They must be hibernating! The past winter (when, I believe some critter was busy storing food in my 900) was one of the worst I've experienced for mice. I killed 20 of them before I got tired of dealing with them. I can only imagine how many went past my traps after one of their buddies already set it off! I live in the country and I've often joked that I share my house with many families of mice. It's just a fact of living in the country.

Scott

We have mice here in the desert, too. A constant battle, since I also feed the birds. I know, a mixed message, providing them with food, and then "evicting" the little bastards. Keep up the good fight, peanut butter is good bait (use the smooth PB, and keep the "crunchy" for yourself, lol). I couldn't tolerate them in the house, that would mean true warfare. Keep your airboxes clean, and ride safely, boys.

Posted: Wed Jan 29, 2014 2:44 pm

"Fuel Standoff" is atomized fuel just sitting in the carburetor or airflow with nowhere to go and eventually will coat a nearby part leaving a residue. With pods, this standoff can occur outside the pod and you'll see it on your jeans. (Ever see a car backfire through the carb when the timing is off? A spark ignited the "fuel standoff"). The natural rotation of the motor causing pulsations in the air stream push and pull the slug of air with the fuel in it.
This is caused by: poor airflow (clogged filter), too much airflow (pods), too rich (incorrect jets or needle position), vacuum leaks (connector tube sealing), camshaft design or any combination of the above.

On your carbs, you can see where the fuel has entered the air stream and since it's on the motor side of the throttle blade, the clogged filter (like having the choke on) and I suspect poor sealing of the connector tubes to be the most likely culprits.
Don't assume for a minute that all the people that worked on this bike in the last 30 years knew what they were doing, they didn't. As evidenced by the installation of socket head screws used to hold the throttle blades.

As I said in a previous post, ALL of the jets and needle settings need to be confirmed as correct for your application.

CV carbs are delicate and precise in their construction and shouldn't be altered to maintain good driveability.

My 2 cents.

J.R.
CBX-tras LLC

Posted: Wed Jun 25, 2014 1:39 am

Guys,

I figured I would try to wrap this thread up and report back on what I did.

I started this thread to show how filthy dirty my carburetor bank had become after riding a season with an air box full of seed that had been stored there by some of the neighborhood mice.

During the cold NY winter months I was able to slowly work at cleaning and then rebuilding my carbs using the Randakk kit. I used a similar kit for my 1100F, so it was a no brainer for me to do the same with my 900F. I know I am moving slowly, but this past weekend, I was finally able to get the carb bank back on the bike and the sync meter attached to verify the settings. A few adjustments later and the engine runs great now. I have to get the tank and body work back on, but that will be easy and fun. With a little more warm weather, I might just get this on the road again this summer.

Here's a few pics of the installation process. A shout out to TomK who I had PC the carb clamps for me. His work is always top notch!

Posted: Wed Jun 25, 2014 2:06 am

Mine had a nest in the air box and the exhaust was full of corn. It had sat for 17 years before I got it.

Posted: Wed Jun 25, 2014 6:31 am

I have to ask - did the engine squeak when running?

Posted: Wed Jun 25, 2014 6:59 am

thx113 wrote:

I have to ask - did the engine squeak when running?

Or did it squeak...and then suddenly quit?

Jebby

Posted: Wed Jun 25, 2014 12:19 pm

In picture # 7 it appears that the bank may not be fully seated into the insulators, but hard to tell for sure. Confused

Posted: Wed Jun 25, 2014 12:55 pm

Glad to hear you have it back together and running, Scott.

Before you removed the carbs, were a lot of cats hanging around the bike? Smile

Posted: Wed Jun 25, 2014 1:07 pm

What a bunch of smart asses! Twisted Evil

Posted: Wed Jun 25, 2014 1:27 pm

1100russ wrote:

What a bunch of smart asses! Twisted Evil

Not being a smart arse at all. I think there is a serious health and safety issue.

That looks like a lot of grain for a couple of mice and nowhere do I see an exercise wheel or any other method of the mice working off any of those calories.

I also notice a lack of ventilation holes in the airbox - this could cause the mice respiratory problems from noxious fumes and vapours from the engine. I think that drilling a dozen or so half inch holes in the airbox should provide adequate fresh air.

Posted: Wed Jun 25, 2014 1:38 pm

I only wish I had taken a picture of the airbox when it was loaded!

I am not surprised that the mice did what they did. Hey, they were storing food for later. I am surprised (and embarrassed Embarassed

), that I never checked the airbox before riding that season. A lot of the maintenance on these bikes is a pain in the ass, but two screws and a peek at the air filter... maybe even take the filter over to my compressor and give the filter element a bit of a cleaning... naw... didn't bother! Dummy (me).

Oh well. Not sure if I mentioned, but the bike is running great and idles nice and smooth. Never did that before. I learned some new tricks this time when performing the bench sync for the carbs and I like the results.

Enjoy the pics!

Scott

Hawk Joined: Sep 05, 2008 Posts: 502 Location: Orlando FL

Grumpy32 wrote:

In picture # 7 it appears that the bank may not be fully seated into the insulators, but hard to tell for sure. Confused

I think I agree with Terry.

Posted: Wed Jun 25, 2014 6:38 pm

I had a guy bring his bike to my garage because of it not not running on 1 cylinder,(Yamaha 650 2 cylinder) Checked air box,carbs,ignition, The left carb was gummed up, cleaned them and put back on. It was still chilly out side so I just had the garage door cracked a little for ventilation and proceeded to start the motor, long story short the left exhaust pipe was stuffed with a Black Wasps' nest. They were pissed and had about a hundred of them flying around!
What a surprise that was.

Posted: Thu Jun 26, 2014 12:30 pm

Guys,

Thanks for the comments.

I was installing the bodywork last evening and noticed that I did not have the normal amount of clearance that is required when placing the right side side panel in place. The panel wants to come into contact with the rear of the air box.

Sounds like I don't have the blasted carbs pushed properly into the insulators properly as was suggested by both Groesbeck and Grumpy. Now that I am paying attention to this detail, I can see that I am not pushed fully in on only the right side (no problems with panel installation over on the left side).

Here's my question... I already pushed these as hard as I could to try to get them inserted properly. What other tricks have you used to get these seated properly? I thought I read once that someone used something like a bike tie down (the kind that has the 'winch' attached) to pull the carb bank into the insulator.

Looking for suggestions to get these seated properly (and then gaining the extra room I need to properly install the right side panel).

Thanks for your time!

Scott

Posted: Thu Jun 26, 2014 12:57 pm

Scott,

What you described is a common occurance. You get one side snapped in nice and tight and then the other side, not knowing that the other side pulled out a bit. Try gently heating up the intake boots with a heat gun and then get in front of the bike, reach around and pull both sides of the carb bank at the same time. I like to wad up a towel and put it between my knee and the frame so that I can get a little more leverage. If you wiggle them up and down a bit, they should pop into place.

Those guys have good eyes to catch that little discrepancy.

Tom

Hawk Joined: Sep 05, 2008 Posts: 502 Location: Orlando FL

If you don't have a heat gun a hair dryer helps alot. Really softens up the boots and makes the job considerably easier. I have wasted alot of time and struggle until learning about the heat.

Posted: Fri Jun 27, 2014 4:10 am

I have silly question: how do the mice get into the air filter plenum? Is it not tightly closed?

Chico

Posted: Fri Jun 27, 2014 10:15 am

chico wrote:

I have silly question: how do the mice get into the air filter plenum? Is it not tightly closed?

Chico

All they need is a small crack or opening and they can squeeze though. Mice are pretty amazing when it comes to flattening out their bodies.