At Wits End - 1999 F4 PROBLEMS!

spcman_spiff · 01-14-2009, 3:33 AM

Ok, firstly lots of good advice here, thanks to those who came before me. Unfortunately, cannot find the answer to my problem, so here goes.

Bike ran great for years, (F4, 1999) without a problem other than a bad coil stick. The bike has new ngk plugs in it at the time I replaced the sticks, (two years ago).

Here is the scoop. Wasn't riding as much, bike did do a little sitting, riding maybe once a month, short distance mostly, work and back, quick trips etc. No problems. Once in a while, longer trips (220 miles rt) ran fine. One day, ride about 10 miles to meet a friend, bike runs fine. On the way back, riding as usual and bike BOGS down big time, like it's running out of gas. Plenty of gas in it. I barely make it to a gas station, fill it up anyway, bike won't start. Battery runs out. Have to pay a guy 50 bucks to load it up into his truck, takes me home, garage it for the night. Put it on charger, next day, try to start, starts right up! Hmmmm...

I don't ride it, figure it's fuel problems. When you turn on the bike, you can hear the pump giving its little rattle and relay kicking in. So I look at the fuel lines, fuel getting to pump, petcock is open. Fuel filter looks clean but I decide I will replace (I didn't use OEM, used a filter from AZ that is similar in size and is FREE FLOWING directional just like original.) Made sure gas is flowing to pump. All ok. Ride the bike in the neighborhood, seems fine. Decide to meet the bird for dinner and take off to meet her on it. Bike rides fine to turnpike, jump on and HIT IT! Get going about 80 real quick, get on hgwy and about half mile down the road, the bike dies. Won't start. Same thing just bogs to dead. Get lucky. Some guy pulls over and helps me right away with a truck and takes me in. Bless him wouldn't take my money.

Get it home after on the truck, quick battery charge, s&g's, try to start it and it starts right up. Hmmm. Now I don't know what it is. Screw with it again fuel line wise, drive it in the neighborhood. Seems fine. Get on it a couple of times and it is ok. Take it to work, seems ok. Coming back, starts to stall and hitch.

Garage it for a month, don't have time. Friend comes over and asks to ride, sure, it starts, he goes neighborhood riding, goes fine. I take it about three miles away, starts to die, barely make it back. Bike is officially now running like crap at all times. Back in the garage. I move, decide I am going to figure this thing out. Replace fuel pump. No difference. Pull carbs off clean the hell out of them. Pull plugs and re-gap, they are clean. Check for spark, good. Put carbs back together after 3 hour acid soak of jets, slow air and anything else that will come out. DRAIN AND REPLACE GAS. Put it all back together, bike runs and runs great. Figure I got it licked. Ride the neighborhood, wheely pickup, seems to be I gotter her back.

Next day, ride it to work. I moved so it's all hwy miles now. Get on hwy, open her up, first and second get it, starts to hesitate in third. WHAT?!!! Worried so I take it easy and the bike DOES run fine if I run at hwy speeds and don't get on throttle. However, bike has NO POWER. You can feel it humping speed wise, little bursts of power , if I peg it, bike will only go 80-90 and that is it. And here I am. What the heck is wrong with this thing?

I really don't want to take it to the stealership. The first guy I talked to when I took it in was like "It's carb work, I know it, we charge 90 and hour and it will take at least 5 hours plus parts to fix it." That's 7 bills for a guess. I could buy a used carb for less. I really don't know what else I could do to the cards. Took the jets out, including slow jet and soaked. Do I need to break the carb down further? Is it the throttle sensor? ICM?

I am getting back into riding and I would really like to figure this out but I am at a loss...

Any ideas?

Thanks!

Jeff

Jetpilot07 · 01-14-2009, 12:02 PM

have you tried to remove the pet-cock from the tank and check the sceen to see if it's clogged if it has that setup...don't know much about the F4s...are you having to charge the battery alot, if you are you might just be running off the battery and running it down as you ride because your stator might be bad and not charging...requirs more v oltage to run the coil packs...

Corvus · 01-14-2009, 3:45 PM

Okay, you probably already checked so it's a long shot... but anything partially clogging up your air intake or lines? Sometimes an object could move and begin blocking flow... which would make it bog badly and limit top-speed. The difficulty starting (just after bogging) could then be temporary flooding / fouling.

The stator explanation makes sense to me too though.

spcman_spiff · 01-14-2009, 5:09 PM

Quote:

Originally Posted by Jetpilot07

have you tried to remove the pet-cock from the tank and check the sceen to see if it's clogged if it has that setup...don't know much about the F4s...are you having to charge the battery alot, if you are you might just be running off the battery and running it down as you ride because your stator might be bad and not charging...requirs more v oltage to run the coil packs...

Battery is fully charged and starts the bike anytime. The bike starts and runs fine, just has no power now. I hit around 7k rpm once in 6th gear and it just doesn't want to go. The funny thing is that off the line shots, the bike feels as good as ever, its just when I get up to hwy speeds that I get hesitation and no power.

spcman_spiff · 01-14-2009, 5:11 PM

Quote:

Originally Posted by Corvus

Okay, you probably already checked so it's a long shot... but anything partially clogging up your air intake or lines? Sometimes an object could move and begin blocking flow... which would make it bog badly and limit top-speed. The difficulty starting (just after bogging) could then be temporary flooding / fouling.

The stator explanation makes sense to me too though.

the bike isn't bogging down to death now, it just doesn't have any power. I am thinking that the carb cleaning did it some good but there is still something wrong. I wondered about it getting air, can you get too much air? It is when I am up to speed that it has no power...

CBR_Matt · 01-14-2009, 8:41 PM

If you have checked the plugs, coils, cleaned the carbs and made sure there is no restriction in the air filter, i would open the tank and peak inside (with a flashlight of course) for rust. Not riding it much and there being air space in the tank can cause rust to form.

I had a Katana with a similar problem. The tank did have rust in it, flaked off and would cover the petcock and cause problems. After the bike sits awhile, it starts and runs for awhile, then same thing happens.

What I think caused this situation was the riding caused the particles to float around the tank. Getting it on the trailer and the ride home sloshed the fuel around in the tank and cleared the valve.

Its worth a look. On a side not, when winterizing a bike, you will more than liekly drain the tank. Get a can of kawasaki (or whatever brand) fogging oil. With the fuel cap open, spray the heck out of the inside of the tank, the oil will adhere inside and prevent rust. Dont worry about the oil itself, the first fresh tank of fuel will clear it out and it WILL NOT cause running problems.

Corvus · 01-15-2009, 4:39 PM

What made me think of LACK of air is your description of the bike having no top end... like when your getting onto the main jets.

About once a week over on the FZ1OA board, someone writes in b/c their bike suddenly won't go over 60 mph, bogs, dies and has a difficult time starting. On that bike, there is a rear facing air intake that is easily filled with anything you may have put in the under-seat storage.

Anyway... the symptoms are somewhat consistent. Do you have a low-speed air circuit as part of the forward facing ram-air like the F3?

Another idea... have you checked for torn slide diaphragms in your carbs? If there is no vacuum pulling up on the slides, then the needle would obstruct the main jet causing a major lack of power once your RPM increases.

spcman_spiff · 01-16-2009, 4:08 AM

Quote:

Originally Posted by CBR_Matt

If you have checked the plugs, coils, cleaned the carbs and made sure there is no restriction in the air filter, i would open the tank and peak inside (with a flashlight of course) for rust. Not riding it much and there being air space in the tank can cause rust to form.

I had a Katana with a similar problem. The tank did have rust in it, flaked off and would cover the petcock and cause problems. After the bike sits awhile, it starts and runs for awhile, then same thing happens.

What I think caused this situation was the riding caused the particles to float around the tank. Getting it on the trailer and the ride home sloshed the fuel around in the tank and cleared the valve.

Its worth a look. On a side not, when winterizing a bike, you will more than liekly drain the tank. Get a can of kawasaki (or whatever brand) fogging oil. With the fuel cap open, spray the heck out of the inside of the tank, the oil will adhere inside and prevent rust. Dont worry about the oil itself, the first fresh tank of fuel will clear it out and it WILL NOT cause running problems.

I completly emptied the gas tank because the stealership stated that he smelled bad gas. In the process I found a quarter in the tank. Alas it had no bearing on performance and gas it streaming full tilt out of the petcock for the full contents of the tank, I watched it...

Thanks for suggestion though!

spcman_spiff · 01-16-2009, 4:13 AM

Quote:

Originally Posted by Corvus

What made me think of LACK of air is your description of the bike having no top end... like when your getting onto the main jets.

About once a week over on the FZ1OA board, someone writes in b/c their bike suddenly won't go over 60 mph, bogs, dies and has a difficult time starting. On that bike, there is a rear facing air intake that is easily filled with anything you may have put in the under-seat storage.

Anyway... the symptoms are somewhat consistent. Do you have a low-speed air circuit as part of the forward facing ram-air like the F3?

Another idea... have you checked for torn slide diaphragms in your carbs? If there is no vacuum pulling up on the slides, then the needle would obstruct the main jet causing a major lack of power once your RPM increases.

Diaphragms are defiantly good. I have the company manual and it is confusing because it has two different model configs, California and 49. It is hard to tell because I bought the bike used and it has been messed with and is not complete as the manual has it. I am going to break down the carb one more time and check the airtube configs as I go. There are some interesting tests that I will try coming from the manual that may explain somethings. Here is keeping my fingers crossed. Next stop. Used carbs. I can get them for 150 so they either work or they don't. At least I can eliminate them....

Thanks for the thoughts!