Need Help setting Float Level. 2nd Gen VFR750

Well that definitely helps. I wasn't too sure if the o-ring would seal well enough if it's only turned in with the vacuum hose.
As for the temperature I heard that over time temperature changes and such can cause it to go out of sync, I thought it might be better to sync it at the normal temperature you would be riding at.

 

It won't cause them to go out of sync. Though you may have to readjust the idle later, may be.

 

Ok....so I hooked up the Carbtune. Carbs were this much out of synch:

I started adjusting them but as the bike was idling and the Engine would get warmer the readings would change and make things quite difficult. I wound up getting the 4 pretty close but definitely not very close. (far from perfect)

Also....as I was adjusting the carbs so they matched the Master carb the bike seemed to sound worse. (rougher)

So I have balanced-ish carbs....and the bike will no longer start. With or without choke...you need to crack the throttle a bit to fire the bike up...and when it does (if the choke is on) the engine will rev up....but eventually you gotta control the idle with the throttle.
Once the bike is at temperature it holds idle fine....but it does sound a bit lumpy.

The bike does pull entirely through the revs quite nicely. It pulls very hard in every gear. I have none of the other issues I did before.....just some new ones.

I'm gonna pull the plugs again and see how they look.

I'm thinking I may need to start turning out the Pilot screws a bit.

 

Checked the plugs...all look fine. Not black...the tips are a tad whitish.

I'll post pics when I get home

 

Perform the sync when the engine is fully warmed up. This will give you the best results.

Glad the Carbtune is working out and that the spark plugs are looking better.

 

All the plugs pretty much look like this:


The tip at the top of the plug looked a bit whiteish...it's hard to see in the picture cause the oil I usually put on the threads rubs off when I remove the plug.

The black mark where the arrow is pointing to is baked on. All plugs were dry.

Anyways...all 4 plugs look like that ^^.

When the Engine is fully warmed up? Meaning when the fan is coming on? Or fully warm meaning where the temp gauge usually sits when I'm riding it?

 

The shell bottom and electrode look black. = rich. BUT seeing your just idling/low revs and just warm, it looks good. The porcelain is not what you read with unleaded fuel. It will give a general idea but nothing to tune with.

You want your engine at least up to normal temps. It may get hotter dicking around adjusting carbs. A good idea is to put a house fan or the like in front of the bike to blow air thru the rads and around the engine to aid cooling. Or jumper the fan wires at the temp switch to run constantly once up to temp. All carb final adjustments should be at normal running temps. you want the carb bodies to get some heat in them.

 

Makes sense....thanks!

For the record:
-The picture of the plug...I rode the bike 150+kms. It's not just from idling.
-These are the same plugs that were in the bike in post #100 (on March 18th) I just cleaned them off quickly with carb cleaner before re-installing them

So are you saying the bike is running rich?

Is that why the bike is hard to start?

 

As noted you'll want to sync the carburetors at normal operating temp.

Have you dialed in the adjustment of the pilot screws?

 

Yes it looks a little rich colored. BUT it also looks like not enough heat. The black is most likely there from idling/carb adj. If you look close where the grd electrode is attached to the shell, you don't see much color. It's hotter there, which burns the deposits,if any, better. The shell (bottom ring) should heat at least 3/4 of the way around and burn off deposits. This would show a greyish color instead of black. Like heated metal. The grd electrode should do the same from tip towards the shell where it is attached.

Those are slight differences you look for in reading plugs. That's why you CAN"T use your plugs NOW for tuning purposes, because they have baked deposits/color on them. You need new plugs and either a race track or country roads. What you can tell with those plugs is the general condition of your combustion. The porcelain is white to a very light tan and the base ring is dark but clean. No oil or any other deposits. They look good. It's cold out compared to summer. Your motor is not going to get as hot, neither is the combustion chamber at this time of year. Come summer temps I'll bet that base ring color gets lighter if all else stays the same. If you put an additive in the fuel, that may color the porcelain like the old days of leaded fuel. If you use leaded fuels you then can "read" the porcelain like half of the charts out there show.

I've read/seen people explain, in present day, about how to read plugs using the OLD lead fuel plug charts pictures. Explaining about porcelain color. No wonder why alot of guys mis-read plugs. Unleaded fuel will NOT stain the porcelain like leaded fuel does. Now read plugs in alcohol (methanol) engines. There is no color what so ever using that fuel.

The reason your bike starts hard could be the way your trying to start it to how the pilots are adjusted to the chokes and the cold weather. Try to keep the throttle closed all the way until it fires at least in cooler temps. I know mine at times of hot weather I may have to hit the starter button let the motor turn over a couple of times and then roll the throttle open a little. Other times I have to keep it completely closed until it fires. You'll just have to figure out what works for your bike. That's where FI shines.

 

Hmmm.....well I do have a fresh set of plugs ready to go in....I was just waiting until I had the bike all sorted out before I put them in.

The bike used to start fine with Full choke...even when it was running pig rich.

Now it needs the throttle cracked open and then it starts up fine....but won't idle unless I control it with the throttle.
(it idles ok when warm but sounds a bit lumpy)

I set the pilots screws to 2.25 turns before I installed the carbs. I brought them out to 2.5 turns this morning but now that grey is telling me the bike might be running rich I'm a bit unsure of what to do.


If the bike won't start with any amount of choke.....but will fire up fine with the throttle cracked open.....what exactly does that mean?

Opening the throttle gives it more gas to allow it to start?
...or opening the throttle gives it more air to start?

(or both)

 

Set the pilots by turning out 2 full turns, as noted, then turn out (about 1/2 a turn) until you hear the idle increase - no need for the Idle Drop Procedure as this actually decreases performance. Remember the pilots are fuel screws meaning out richens the mixture and in leans the mixture.

Regarding the choke, did you check all the enrichener circuits when you had the carbs on the bench?

 

Well these recent posts have made me feel a little better about my bike. I still haven't synced my carbs yet (it runs good so they cant be TOO far off) but whenever my bike is warm I have to turn the throttle the slightest bit to start it. As long as the choke is in when I start it cold it's not necessary though.

 

May be I said something wrong. You asked about the color of your plugs and I gave an opinion on the richness color. You don't know how the a/f ratio is in you bike except that it is not that bad. The richness color on the plugs are more than likely from using the choke and the idle/carb adjust.

That's why you can not read used plugs for tuning. Your plugs and everybody else's will look like that if to much choke and idle lasts just a little while. Once a plug gets marked/burned like that it's hard to get off. You would have to run in the upper rpms for a while to do that. Which depending how rich colored they looked to begin with may not burn off completely. Something that slight will not hurt either as far as the plug goes.

Your pilot screws may be better at 2 1/2 to 3 turns to make your bike idle well and start when cold. It may not. Don't worry about the plugs now they are fine. Just get the motor to idle the best you can then sync the carbs. After sync you may have to go back and change the pilots a tad. You carbs have several circuits in them. Idle, mid, high. Any one of those or all of them can run rich or lean depending how the carb is set up. So when you say your motor is runing rich, the question is where/when is it running rich. Plug reading may help with that on the top end. An exhaust analyzer will be the way to go to see what all the circuits are doing for tuning purposes.

 

I don't understand. I start at one carb...turn the pilot screw out slowly till I hear the idle increase....then what? Reset the idle and do the same on the next 3 carbs?

Isn't that the idle drop procedure? ^^^

 

Yeah....mine is the opposite. I need to crack the throttle to start the bike when cold.
When the engine is at temp it starts without issue.

 

The Idle Drop Procedure is a bit different than what I am recommending.

From the starting point (let's say two turns out) turn ALL the screws the same 1/4 turn out, stop and listen.

Then either:

1. turn them back in the 1/4 turn and then an extra 1/4 turn in and listen
2. leave them as is if responding correctly (see notes below)
3. turn them another 1/4 turn out and listen.

Give the engine time to respond to the change.

Use the throttle to augment your judgment, i.e. too LEAN will make the idle hang a little and not come down quickly when the throttle is closed, like it should. Too RICH and the idle will come down fine, but then will dip below the normal idle for a second and then come back up to normal.

 

Got it. Thanks IC.

I still have yet to see how the bike will respond to the 2 1/2 turns out position that I set it to last....weather has been too crappy lately.