Need Help setting Float Level. 2nd Gen VFR750

Matt, i suspect you probably have one cylinder that's not firing.

Judging from the vapor exiting from the mufflers, i'd check the cylinders connected to the right side exhaust.

Slow startup after carb work is normal unless you let new fuel sit in carbs for an hour or so before trying.

I know you're tired of messing aboot, but you know you can find the offending cylinder by lightly touching each exhaust header aboot 45 seconds after starting, finding the cool one.

Alternatively, an inspection of sparkplugs would likely show the fault. Switching plugs around can prove a fouled or otherwise defective plug.

 

Sounds good.

When it was running I did check the front 2 headers (by licking a thick clean cloth, wrapping it around my finger and quickly touching the pipe) both were hot enough to sizzle the cloth.

I'm planning on going back this Monday to try and get the bike up to temp and doing a much needed oil change.

Also, I do eventually plan on changing the plugs again since they've had a rough life in the poorly running bike...constantly getting fouled.

If after that, and a few tweaks, the bike still runs assy.... I'll take the bike home and pull the carbs again. Start from square one and work my way forward again.

 

If I could suggest, synchronize the carburetors with a manometer before pulling them. You may find that this is all that is required.

 

Good luck, Matt, but i trust you did OK on the parts replacement. Again, inspect plugs to see if you can find one that's giving you trouble. You've narrowed search to rear cylinders, and yes, you gotta get way down on your knees to reach the rear header pipes.

If a float level was incorrectly adjusted, you'd probably see it on the plugs.

 

I do have the carbtune ordered...I'll check the balance when it comes in.

 

So I visited the bike again to do an oil change.


Put the battery in....full choke...pressed the started button and it fired right up. I let it run for a few seconds then shut it off.

I replaced all 4 plugs with new ones. Every plug I removed was black...and wet. I'll give the new plugs some time before I remove them and inspect them for running conditions.

I started the bike and ran it....it seemed to run good. After the bike warmed up a bit I gave the throttle a quick rev and the bike quickly died. I tried starting her up again but it was making a loud and fast clicking noise. (not like a dead battery) After a few tries the bike stopped making the clicking noise and with some throttle it started back up again. (This happened briefly last season...but never to this extreme. Starter clutch?)

After all that it ran like this:
[video=youtube;wGfZN9zFu9g]http://www.youtube.com/watch?v=wGfZN9zFu9g[/video]
It felt like everytime I rev'd it there was a brief moment, as the revs fell, where the bike hesitated before falling back to idle.

Anyways.....I did the oil change....and put the bike back in the corner....I'm still waiting for the carbtune as well as other parts.

 

I'm gonna attempt to synch the carbs tomorrow....I have a feeling the slides might be sticking though.


Wish me luck

 

Sounds like you're really playing with fire now! Burn it down! haha

sounds good to me keep up the good work!

 

Read and study the "Installation and Troubleshooting" guide furnished with every "Dynojet" kit or Factory Pro instructions before proceeding, i'd suggest.

 

I should do this before doing a carb synch??

 

Hmmm...having trouble finding these guides online

 

FP link here:

http://vfrworld.com/forums/1st-2nd-generation-1983-1989/31843-rejetting-vf500f.html#post276042

 

To different things, both equally important.

My rec is to read the Factory Pro jetting guidelines and keep this in your back pocket. Start with properly synchronizing the carburetors using a manometer.

 

Hey Slowbird, sorry I haven't jumped on this sooner... I'm in Delaware visiting my family and haven't been on the laptop much

For starters let me just say that I can't believe the whole "plank of wood and a soft mallet" thing is still being suggested to assist with re-installing the carbs on a cold bike. Do you guys NOT remember what happened to my filter plate by performing this method? Allow me to remind you that JB Weld on a $200+ piece of aluminum looks crappy as hell even though it worked just fine (you might not be so lucky getting a cracked piece as easy to repair as I did). To help with installation, next time use a small tube of Vaseline Lip Balm (about a pea size dab per boot) and apply to warmed boots -- take the adjuster rings off and toss em in the microwave for a bit. Also, when installing them make sure that the adjuster rings are loose enough to allow them to bend out of shape. That's unfortunately why my plenum broke -- I was trying to force the carbs onto the boots with the adjusters not loosened up all the way. OH, and get a pick tool... kind of looks like a pointed screwdriver with a wicked 90 degree at the tip. Helps to get the boots around the base of the carbs. I'd post a pic of it, but it's 2400 miles away right now

Next up, according to Honda the multiple carbureted V4's need to be sync'd every time they are removed from the block due to small differences in pressure from installation. Adjustments of as little as a 1/8 turn of a balance screw will offset a cylinder enough to cause the engine to begin knocking and drop the set idle by 50 rpm's. It is also recommended that a normally driven bike that is not stored, but used every day, to be sync'd at 8k mile intervals.

Purchasing a carb sync tool (manometer) will save you so much money in the long run. I got my Motion Pro through Apache Honda using my student discount. There are cheaper ones out there, and they all do the same job... I just felt more comfy getting that particular one cause that's what we used at MMI. Remember that when you use it for the first time that you have to hook all four hoses to the #1 cylinder using the calibration piece that comes with it (it basically is a plastic piece with 5 nipples on it to connect it like a 4 into 1 adapter). Each time you sync your carbs by yourself you save yourself about $450-$600 over dealer cost just by spending $90 on the tool they use and knowing how to properly use it.

I also bought what we call a crack pipe, which is a 90 degree screwdriver used to adjust the carbs. My screws were so stiff that the stupid tool wouldn't turn them, so I ended up using an extended socket driver (not as accurate but it did the job).

As for the videos.... your bike sounds exactly like my '86 did after I cleaned and bench sync'd my carbs. The popping/ticking noise is the cylinders firing out of balance from needing to be properly sync'd. The vapor coming out of the exhaust is normal, that's just the water being created by improperly tuned carbs feeding abnormal amounts of fuel into the system (yes, burnt gas makes water vapor along with CO and HC's). The excess puffing from the exhaust may be a hose routing issue... make sure that all of the hoses for the vacuum system are installed properly and that you don't have any leaks, especially if it's a California model.

 

Well noted Lazy!

 

....."Each time you sync your carbs by yourself you save yourself about $450-$600 over dealer cost ."

That can't possibly be accurate or dealers are getting away with more shit than i ever imagined.

I charge about $125 to synch a VFR....if the owner brings in the bike with the lower fairings removed. No reason why the job should take over 1 1/2 hours maximum

 

Last year before I did my own carb clean on my '86, Apache Honda quoted me 1.5 hrs plus .5 hrs per carb to clean them @ $105/hr, plus $45 per carb rebuild kit = $547.50

That includes a carb sync and idle drop.

 

Ok.....carb synch done. It was quite the pita...screws quite difficult to reach but luckily only the rears were off balance from the #1 cylinder.

Also the left rear cylinder screw hole where the vacuum lines attach for the carb synch seems to have some messed up threads.

Anyways...after all 4 cylinders lined up on the carbtune I notice right away a improvement in the idling.

Before taking the bike for a test ride I noticed a watery puddle of soot under the bike.....further examination showed it to be black sooty water dripping from the exhaust can drain holes.

What's the cause of super watery exhaust? (The soot must mean it's running rich)
Revving the bike shows a tiny bit of black smoke from the exhaust....but it's difficult to notice.

Took the bike for a spin...it falls on it's face when you give it anything but light-moderate throttle.
Stutters in the Mid-range.
Lack of power.

....all around suckage. Still rideable...I took it home....but a huge disappointment.

I'll pull the plugs tomorrow morning and see what they look like. (my guess is they're gonna be black)

 

OK.....here are the plugs:
Right Rear

Left Rear

Front Right

Front Left


Looks like I'm still stuck with my original problem... http://vfrworld.com/forums/1st-2nd-generation-1983-1989/32369-carb-problems-my-2nd-gen.html

...both right cylinders are running rich...the front Right plug is fouling up.....even after replacing the float assy.

Would appreciate any and all comments and advice at this time.