Bought my 98 f3 a few weeks back. ran good even though I didn't take it above 8k rpm. Last week I thought I would paint it so I took off all body and gas tank. I also cleaned the k&n and replaced spark plugs.
Installed everything back and ran good just like it did before. I've been having some trouble with it dieing on me and not starting or not wanting to start at all. Im thinking its the rectifier. yesterday for example I had to get a jump two times to get it to start.
Anyways, this morning something just didn't sound right coming from the engine. Makes a weird noise kind of like something just isn't right. I pulled 3 plugs (4th I can pull but its a pain) and I noticed that the tips are white. Not as white as paper but pretty white. From my understand it means that it is running lean. Now, my question is. The bike ran fine after the maintance I did. Could this engine noise and white plugs just be that the rectifier is acting up? Or could this mean that the jets aren't large enough for my mods (two brothers pipe and k&n filter)? Or am I just dumb and the spark plugs are suppose to be kind of white. But why was it sounding fine before if all I did was clean the filter and replaced spark plugs. It runs fine when it does and thats also what has me thumped is that this morning it started up just fine but yesterday like I mentioned it left me standed twice. any input would be greatly appreciated. Thanks

Here are the pictures of the plugs. Not the best but thats all my camera can do.

 

Those plugs look totally fine for being a week old. You're barking up the wrong tree.

As for the not starting, what makes you think it's the rectifier? That's an odd initial conclusion to jump to.


Please provide as much detail as you possibly can; "not wanting to start" is a totaly useless description of the problem. We need physical observations of what's going on in order to even try to give you troubleshooting tips. Sounds, lights, dials, etc.

 

Agreed. I would be more concerned about removing the tank and airbox to verify that I connected all of the vacuum lines properly as they were before the tank was removed.

 

I raised the tank and all connections are good.
What I also noticed was that if I give it a lot of gas in neutral or 1st it dies. That made me think that its getting too much air.
So what I did was cover more then half the air snorkle with tape to reduce the air flow to the filter. Now, I can give it as much gas as I want in neutral or in 1st and it doesn't die.
It also seems to run better with the restricted air flow. But that engine noise is still there.
Regarding the starting again this morning it didn't want to start. Im going to replace the battery today and go from there. If not then the rectifier. After all the research I've done on the site that seems to be the best plan for me.
BTW, when I check oil level does the bike need to be on the stand or held upright? And do I screw the check level in or just push it in until it hits the threads? Im thinking the engine noise might be from low oil even though the oil level light is not on. I added the recommended amount of oil when I did filter and oil change just 2 weeks ago.

 

You're all over the map here. Lets walk through this:

I think you mean "If I open the throttle too wide," unless you are somehow manually injecting gas. I'm not trying to be a dick here, but it relates to what you say next:

So what you did here is reduce a functional area of the bike to BELOW factory specs in order to make it function properly. This implies that a related area is not UP to factory specs. You didn't fix anything, you just uncovered a clue. You have confirmed that there is too much air coming in. Since your "too much" is actually the manufacturer's intended amount, then this means you are actually getting *too little gas.* Your bike is running very LEAN.

What noise?????? All you said is:

Throw us a bone here. There's a lot of stuff in an engine that can make a LOT of weird noises.


Are you thinking: Bad rectifier = fried battery + fuel pump not working right = lean a/f mixture? If you can get the bike started, I'd go straight to testing the r/r. Failing that, test the pump and pump relay (they go a lot as well).



Stand is fine, and you don't have to screw it in. If you have to stand the bike upright and screw in the dipstick to get it above the OK line, then you need oil.

That's not a level light, it's a pressure light. Oil level has no effect on it, unless you leak\burn\forget to put in a severe amount, and actually cause a drop in pressure.

Immeidately after you put the oil in, did you check the level? Has the floor of your garage coincidentally turned a grimey black color?

 

This is my first bike you please be patient with me,lol.

If I open the throttle a lot in neutral or in 1st gear the bike will stall. Seeing the white tips on the spark plugs was another sign that I thought I am running lean.
From my research adding a k&n filter and pipe and not getting bigger jets will make the bike run lean. Thats why I thought that if I would cover up some of the intake it would not allow as much air into the carbs as before. From what I understand a k&n will allow more air into the intake then a stock filter.

I still think the bike is operating at its OEM limits its just that with the addition of the filter and pipe it now does not have sufficent fuel to compensate for the extra air going in and out.

The engine noise is hard to explain. It kind of sounds like a ticking sound or knocking sound. I know this doesn't help much but its really hard to explain. Maybe detonation or something along those lines which is caused by the fuel mixture not being correct at idle. When I ride the bike I don't hear it and the bike performs well.

Idle when the bike is warmed up for a few minutes is ~1500. Once I ride around and come to a stop the bike idles at ~2000. This is another problem that I have not mentioned.
Im trying to fix this all by myself as I have no paid much for the bike and don't want to have a professional repair it for me for a large amount of money because I am already looking to purchase something newer and bigger. I bought this bike just to learn how to ride.

I am installing a new battery today to see what it does. I will see if this resolves the starting/stopping problems.

 

See, that's helpful information there. Having a massive intake \ exhaust system like that, but stock jets will make the bike run VERY lean.


Does it occur at regular intervals? Does the speed of the sound increase with engine speed? It could be a loose cam chain, or something similar. If it was backfiring, you would definately know that sound. A lean mixture doesn't really lead to backfiring.

Sounds like you're not lettign it warm up enough. Are you warming it up with the choke? You could also try riding with the choke permanently on slightly, this will help to even the air/fuel out a bit until you can get some bigger jets in there. You want the bike to idle around 1200.

 

ok well the new battery is in and starts just fine. I killed the engine and started it up again a bunch of times and drove it around and everything seems to be fine with that problem.
What I noticed was that with the snorkle partially covered I got some backfiring. Which leads me to believe that now less air in getting in the engine. Then I took the cover off the snorkle and again it would stall if I gave it a lot of throttle in neutral or 1st. So I think what I will do is cover the snorkle partcially and see how that goes.

Would it be wise to ride with the snorkle paritally covered (less air coming in the engine) untill I can get around to changing out the jets? I do see that the water temp goes up when I leave the bike sitting in neutral, but as soon as the bike is moving it goes back down to normal. Which again leads me to believe that it is running lean at low rpm.

I read somewere that there are two jets? One for low speeds then another for high speeds or higher rpm? Is this correct? Is it possible that it is running lean at low rpms but running fine at higher rpms?

Regarding the engine noise, yes it does kind of sound like a loose chain. Is there some sort of chain inside the engine?

How would I be able to adjust the idle rpm to lower it to normal? Do I need to remove tank and do each carb seperate? or is there a **** higher up that I can turn?

If I ride with choke partially on, does that mean that more fuel will go into the engine then with it off? Would it be okay to ride with it partially on for a long period of time? I usually just use it when its a cold start and even then just keep it on for 30 seconds cause the rpm jumps.

 

This is exactly what the choke does.

So long as the temp needle stays below 3/4 up, this is absolutely normal, and you should not concern yourself with it at all. If it was running lean, your temp would actually be lower (less combustion).



Yes. They are called "Slow" and "Main." A "jet kit" will have you drill out wider holes for the mains, and install larger jets in there.

. . . . . . .possibly. The holes on your slow jets (low RPM) are V E R Y tiny, and get clogged V E R Y easy. You may just need to pull them out and clean them. This is incredibly true if it's never been done before on this bike.

I believe there are a couple. One of them is the cam chain, which reportedly comes loose on occasion, and taps the side of the case. That's outside of my area of expertise, though. May want to start a new thread on that one.

There's a little black **** sticking out of the fairing vent below your fuel petcock. Turn left to lower the idle, right to raise. If it's not there, it may have fallen inside. Pull the fairing off and look around. It's on a long black cable.

It actually means less air will go into the engine. The choke covers up the air intakes on your carbs (Just like you were partially covering the snorkel above).

From a cold start you want to leave it on for a couple of minutes. It should be up around 4k RPM. Riding with the choke on is a problem because according to your situation, you only need it at low speeds. Keeping it on all the time can lead to massive gas consumption, and backfires.

Pick up some seafoam, and run it through the gas while the bike is warm. If it's just a minor clogged slow jet issue, that may clean it out, and take care of all of that.

 

OK well just to give you guys an update.

After installing the new battery I am no longer having issues with starting or dieing. Every time I go to start it, it starts right up.

The issue with it runnning lean I think I have temporarly resolved with covering about a 1/4 of the intake snorkle and using some choke while driving. I have been getting some backfiring while driving and I rather hear that then to know thats its lean. I will continue to play with the choke and see if I can find a position in which I don't get the backfiring but also don't run lean.

I have picked up some seafoam and have put the recommended amount in the tank according to the capacity of the tank. I think I'll put some in there for the next few tanks. Maybe that will help the situation a little.

After more riding I will pull the plugs again next week and see what they look like. That should give me an idea of how my air/fuel mixture is.

I guess I should start looking into ordering a jet kit. Do these jet kits come with instructions? Anybody happen to have the instructions online so that I can get a feel of what its going to take to install them? Which kit is best? Thanks