Help me with my VF500!

Ok, i'm going to try to combign everything I have posted in multiple places in this thread.

I bought this VF500 just over a week ago, it is running pretty good minus the idle problem which I was told about. So if anyone can shed some light on what I need to do, and how important it is to get it done soon let me know. It was idling great when I got home from practice, I let it sit there and it idled right at 1100 with no problem, but it also wasn't too warm yet...

Here We go!

Here is a video of the bike idleing, I think it is because it needs the carbs synced, that is what the previous owner thought as well. I think it may be the valves that have the problem also, but i'm unsure on that part. Here is a video of it the day i got it. http://youtube.com/watch?v=V76sg_Yywi4

Now my next question was about a tube that has smoke and oil spurting out of it some. It isn't a big deal to me because it is tucked inside the fairing, but is it a big deal to the bike? http://youtube.com/watch?v=YQFf3SGJzos
The bike also seems to be "clacky" in that video if that makes any since, and that maybe it is missing on a cylinder because of the popping out of the exhaust. It pops when I give it gas, for example if i'm riding at 4K rpms and roll the throttle it pops out of the right side exhaust only. Also the right side pumps less air out than the right side. (this may be due to the syncronization)

So let me know if you guys have any insight on where I should start with all of this nonsence. Right now I have been riding it around in town, nothing too hard or high speed, take it easy on her for the most part.

 

Sounds like it is idling at around 6-700. If it's really idling at 1100 then my guess is one of the sparkboxes or a coil is bad. Start by pulling a spark plug while it is running and note the effects.

The tube looks like a crankcase breather tube. I'm not familiar with the VF500 so I'm not sure if it goes to a crankase reservoir or if it goes to the airbox, or if it is supposed to go to ground (usually capped). Get a clymers and read it cover to cover.

The popping out of the exhaust is incomplete combustion. Either too lean, too rich, or bad spark.

What's the oil level look like?
Pull all 4 sparkplugs and post a picture denoting each cylinder's spark plug.

The valves get quieter over time. A little clacking as the bike warms up is normal. It should go away almost completely when warm. If you hear a softer clacking, it's probably loose tensioners. Nothing major, but you can replace them if you want to.

 

It's not running on all 4! It also sounds as if you had a tappet back out. That's way too much noise comig from your top end. I would take the valve covers off today and see what's goig on in there. A compression and/or leakdown test should tell you which cylinder to focus your attention on. I wouldn't ride it anywhere as is.

 

Also, if you've got excessive smoke and oil coming from your breather you either have way too much oil in the crankcase or "blow-by" allowing combustion pressure to get past the rings thus pressurizing your crankcase. Again, I wouldn't be riding it.

 

It seems like you've got either a valve problem and/or a piston ring problem. Seems more like at least one stuck piston ring--you can hear the piston slapping, and the engine is pushing oil out of the crankcase tube. Get a manual, take the engine out and find someone with experience to look at it.

 

In the video's it isn't ever actually idleing at 1100, the first time it did that was when I rode it home today.

The video with the fairing off is after I got it warmed up. (it tends to only smoke out of the tube when it is warm) And i'm almost positive the tube is from the rear crankcase vent tube.

Oil level is dead center of the dip stick while sitting flat (no center stand or side stand)

My Clymers is in the mail. I'll start to get serious about this stuff either next week or the week after (as long as it isn't life threatening to my cycle)

I'm new to this type of thing, but can usually figure things out with a little help

 

Eeek, My VF500 has a High idle problem though sounds NOTHING like yours (though if I remember right you have an aftermarket exhaust?) almost sounds like it's trying to be a Harley.

If you want I can scan in certain pages from my Clymer manual. I'd invest in a new Air Filter while you're working on it (it's literally 5 screws to get to the air box).

 

I'm going to have to WAY disagree with many of the comments posted so far. That bike sounds totally normal for a VF500F, albeit one with clogged carbs! I'd get those carbs off and perform a thorough cleaning to them. Be sure to check the diaphragms too. A good sync will round out the process. I think you'll find that it runs much better after that!

 

first CLEAN THE CARBS! it's your low idle jets. It took me 3 tries to get mine totally clean.

Take the tank and side farrings off, airbox off. and LEAVE the carbs on the carb plate...unscrew to losen the intake boot clamps and pull up and rock back and fourth to get the carbs off as a unit. All the carbs can be cleaned without removing them from the "plate". Take the bowls off and unscrew the jets ( flat head screwriver or 7mm socket ) and clean them like no tomorrow! the low idle jets have a hole the goes from bottom to top and is about 24-26 gauge wire thickness. gunk gets in this hole very easilyto tell if they are clean you can spay carb cleaner in 1 end ( the end that the little red straw fit in) and it will come out fast on the other side.

The tube is the crankcase breather system. You will have 1 tube attached to the backside of the intake "Plate" that goes to a box behind the battery, another tube that goes from just above the rightside cover back to that same box, and a third tube going from the lower part of that box to the ground. This tube needs a "cap" at the end ( this may be all that you are missing ) so that the pressure gets routed back to the intake. The litte block box behind the battery collects oil, The tube going to the ground is the drain tube. Every so often you are to open it and drain out the black box so that it can collect more oil...This tube should also be secured inbetween the 2 swingarm sides and in front of the rear tire on the right side. Their should be a few other tubs at this location. 1 of them is the vent tube for the battery...


Hope I helped!

 

I will plan on taking the carbs off and cleaing and syncing them, the tube that is spurting out oil and smoke should be plugged? 100% sure on this? I don't want to mess anything up.

Thanks for the help so far!

 

Yup! the one on the right is the Crank case vent tube, On the left ( clear ) is the battery vent, and the middle is the coolent overflow tube.....

 

Sorry to hijack the thread, but I decided to take off my carbs for a cleaning today and I'm stuck; I figure if I had this problem someone else might as well.

I'm up to the point where the rubber intake tube clamps are undone and the service manual says to simply lift the carb assy. out.

However, since the carbs are in an upside down "V" shape, lifting straight up doesn't get me anywhere. Lifting from the front/rear doesn't give enough clearance to get the respective carbs out of the tubes. I've tried every which way get even one carb out of the boot, but to no avail.

Right now the bike is sitting in my garage with (clean) socks coming out of the intake as block offs.

 

+1, it's the carbs. Damn I'm glad I went fuel injection!

 

It will take some force, Lift up on the plate ( back side ) and rock left to right as you lift. and Make sure that the boot clamps are totally free....

 

Got it!

When I broke down the carbs I was surprised to see that it was pretty much spotless, no gunk in the bowls, no tears in any of the diaphragms, I some gunk to blow out of the jets with carb cleaner and an air compressor, but other than that it was spotless. The float levels were all speced right (If i did the measurement right) and all the respective needles were normal.

I did find out that all my boots are cracked, one of them is even split, so i guess my bike's out of commission until I can get some.

EDIT: Just remembered an important detail. None of my pilot screws have O-rings.... I could tell that they had been tampered with before because the metal drill out plugs were removed, how big of a problem is this?

 

I bet the o-rings might still be in the pilot bore. Take a flashlight and look.

A good trick for removal is to use a long deck screw with wide threads.
Insert the screw into the pilot bore.
GENTLY turn clockwise until it stops.
Turn back 1/4 turn and pull out. The washer and o-ring should be on the screw threads.

Order new boots.
When re-installing the new boots, smear sylglide or vaseline on the inside of the boots to make installation easier.

Position the boots like this: http://rides.webshots.com/photo/2167995950062806610XWsZwc?vhost=rides
and you will be able to rock them in a "Z" pattern and easily seat all 4 carbs.

Since you have the carbs out, I know a guy on another board that sells sets of stainless allen head screws for the carbs and clamps. He should have a set for the VF500. It makes it so much easier to remove and install them. He also has the pilot screw washer and o-rings.

 

I did later check for the O-Rings inside the carb, you called it, they were there :redface: .

However, now my concern is that I KNOW my carb has been rejetted, my service manaul specs 105 High/38Low jets for my model year, my carbs are stamped 90 Highs and 35 lows. They're Kei Hin branded (not aftermarket dynojet); my only guess is because the original owner lived in Simi Valley abou 800 feet above sea level, but even then that altitude isn't anything a pilot adjustment shouldn't take care of (as I understand from the service manaul).

As for the aftermarket hardware, how does it make it easier to remove the boots? I didn't have difficulty loosening the boots at all, just rocking the whole assy out.

EEk, I'm taking over this thread, if I have anything else I'll start my own thread.

 

It makes it alot faster to loosen the boot clamps and easier to work on the carbs. No phillips heads to drill out. Every single phillips screw on the carb save the throttle screw is replaced with allenhead bolts - including the ones inside the plenum.

With the tank, sidecovers and seat already off, I was able to remove the carbs in 15 minutes flat.

He has an E-bay ID of "fngster". He doesn't have any bolt sets for sale at this moment, but I know he has them...

Note: I am not affiliated with this guy whatsoever. He just a good guy to do business with.

 

Ok, so I got my carbs out, So far that Is all I have done on my problems... My first question, when the throttle cable is turned, all 4 carbs should turn open at the same time correct? Mine I only have 2 of them that react with the circle that the throttle cable turns. The other 2 are on their own, and only one of them reacts when I turn the thing connected to it, the the other one doesn't spring back to place, it is just free turning... I'm figureing this could be a big problem with my bike, A spring fell off when I was holding he carbs just looking at them... I'll take pictures later and see if anyone knows what the problem is...

So, what should be my first things to do now that the carbs are off... And how can I sync them with them off?

 

Eek, all 4 carbs should open at the same time no matter where on the linkage chain you open it up.

Did you remove the carbs off the air chamber? (meaning you'd have had to have bent the phillips head block tabs back to allow access to the screws).

That'd be my guess how you lost a spring, that carb assy is pretty solidly built, I dunno how you've lost a linkage connection and a spring.

As for the syncing, I don't remember which thread or who said it, but another member mentioned doing a bench sync with a 3/32 inch piece of paper, slipping the paper inbetween the bore and the throttle plate on each carb, adjusting until you feel the same resistance on each carb

I bought a set of 3 carbs (I forget which number's missing) on ebay for spare parts, they still have all the linkages/springs, if you can identify which ones you need, I'll mail them to you for cost of shipping.


Best of luck.