[vietladin]

My current bike is an 02 f4i, with 19,xxx miles on it. Ran into some problems, and here's what I have changed so far: Stator, recitfier, fuel tank, fuel pressure regulator, throttle body, map sensor, NGK iridium plugs, cam chain tensioner. Did a full oil change, etc. The only mods are a Yoshimura slip on, and lower gearing. Here's my problem: The bike lags, until it hits 2000-2500 rpm's, then she pulls hard all the way, with no problems. When the bike is just idling, and you WOT fast, she sputters, then revs up, then sounds like she is going to die out. But, if you just rev her up slowly, she revs up fine, and doesn't idle like she's going to die out. What gives? Should I slap on my power commander, and see if it will help? I'm out of ideas, and as you can see, I have changed out a lot of parts already. Thanks for your help.

[Maholli]

Originally Posted by vietladin

Should I slap on my power commander, and see if it will help?

Yes.. It should smooth it out.. I would try that and then go from there... I bet it will help alot..

[vietladin]

Originally Posted by Maholli

Yes.. It should smooth it out.. I would try that and then go from there... I bet it will help alot..

The reason I ask, is because, Honda mechanic told me that a slip on throws the fuel curve off. Especially, if you have race baffles. I'm not sure what my Yosh Carbon has, though.

[Maholli]

Your power commander should eliminate most of your problems.. Its always best to have a custom map done to eliminate the flat spots and really smooth everything out.. Here is the map for a 2002 F4i with a Yoshimura RS-3 slip-on exhaust and stock air filter...M108-008...

Power Commander Downloads and Product Purchases, Maps, Installation Guides, Accessories

[vietladin]

Originally Posted by Maholli

Your power commander should eliminate most of your problems.. Its always best to have a custom map done to eliminate the flat spots and really smooth everything out.. Here is the map for a 2002 F4i with a Yoshimura RS-3 slip-on exhaust and stock air filter...M108-008...

Power Commander Downloads and Product Purchases, Maps, Installation Guides, Accessories

Yeah, I saw that map on the pc website. But, is the rs-3, the same as the carbon?

[Maholli]

The RS-3 comes in Polished Stainless Steel, Titanium, and Carbon Fiber with race or zyclone baffles.. The type of sleeve isn't going to matter but you do need to make sure its the RS-3.. It should say somewhere on the pipe what kind it is or atleast my old yoshi did...

For the 2002 F4i its either RS-3 or Tri-oval..

[vietladin]

Originally Posted by Maholli

The RS-3 comes in Polished Stainless Steel, Titanium, and Carbon Fiber with race or zyclone baffles.. The type of sleeve isn't going to matter but you do need to make sure its the RS-3.. It should say somewhere on the pipe what kind it is or atleast my old yoshi did...

For the 2002 F4i its either RS-3 or Tri-oval..

I know for a fact, it's not a tri-oval. Funny thing is, that the Yosh Plate that's riveted on the can, fell off. I'll try the pc3 tonight, and update. Thanks for the quick reply.

[Maholli]

Well if its not the tri-oval then the only other can yoshi has for the 2002 F4i is the RS-3.. Download the map and you should see alot of improvement.. If that doesn't help then I would have it mapped.. That is always the best anyways.. I can come down to Honolulu and help..

[vietladin]

Originally Posted by Maholli

Well if its not the tri-oval then the only other can yoshi has for the 2002 F4i is the RS-3.. Download the map and you should see alot of improvement.. If that doesn't help then I would have it mapped.. That is always the best anyways.. I can come down to Honolulu and help..

Sure, you come down here, and i'll show you around the islands. Hell, we can just ride around, once you get my bike running good.

[Maholli]

The islands.. .. Man I would love to ride a bike on Oahu.. 1 to 72 to 83 to 99 to 2 then back to 1 or atleast I think thats the loop or its something like that.. Anyways I wish.. Maui seems like it would be great for a bike too..

[vietladin]

Originally Posted by Maholli

The islands.. .. Man I would love to ride a bike on Oahu.. 1 to 72 to 83 to 99 to 2 then back to 1 or atleast I think thats the loop or its something like that.. Anyways I wish.. Maui seems like it would be great for a bike too..

I just started riding, so i'm afraid of twisties. On top of that, my front tire is balding, and it's been rainy here in the islands, and that means pot hole central.

[Maholli]

Well a good front tire needs to be your next dollar spent on your F4i..

[vietladin]

Originally Posted by Maholli

Well a good front tire needs to be your next dollar spent on your F4i..

I think i'm just going to replace both. The bike I purchased, was sitting for over a year, in the elements. On top of that, I don't like replacing just one tire.

[Twincam]

Have you managed to sort the problem out?

Put the PC on ans then get it dyno'd and set up 100% with a custom map. I would be amazed if it didnt work...

[sospelotudo]

Originally Posted by vietladin

...here's what I have changed so far: Stator, recitfier, fuel tank, fuel pressure regulator, throttle body, map sensor...

Were all of those parts new? Why did you change the throttle body? Was`the replacement TPS known to be functioning correctly? What did the old plugs look like? The Power commander is not really a fix-all. It only modifies the maps following the O.E.M. componentry inputs, so if there is something else wrong it won't really fix it, even if it does run better. From a diagnostic standpoint, the PC just adds another variable. Lets try to figure out the problem first. Try putting the stock exhaust on (if you have it) and see if it still has the problem, I bet it will...

[vietladin]

Originally Posted by sospelotudo

Were all of those parts new? Why did you change the throttle body? Was`the replacement TPS known to be functioning correctly? What did the old plugs look like? The Power commander is not really a fix-all. It only modifies the maps following the O.E.M. componentry inputs, so if there is something else wrong it won't really fix it, even if it does run better. From a diagnostic standpoint, the PC just adds another variable. Lets try to figure out the problem first. Try putting the stock exhaust on (if you have it) and see if it still has the problem, I bet it will...

Actually, there is something I forgot to mention. I had a guy change out my cam chain tensioner, and i'm thinking that he may have not had everything at top dead center.

[sospelotudo]

Originally Posted by vietladin

Actually, there is something I forgot to mention. I had a guy change out my cam chain tensioner, and i'm thinking that he may have not had everything at top dead center.

Usually you can change the tensioner without upsetting the timing. Did he do a valve adjustment at the same time or something?

[vietladin]

Originally Posted by sospelotudo

Usually you can change the tensioner without upsetting the timing. Did he do a valve adjustment at the same time or something?

No, he didn't. The valves aren't ticking or anything, so I know they aren't due for a lift job yet. I think i'm just going to take the bike to Honda, and pay the 75 to have them diagnose the problem. Hopefully, they can give me a rock solid answer, on what the problem is.

[badazz 1K]

1st yes the PCIII will make a difference

2nd I love how no one noticed its a 600..... they have NO power at low RPMs!!!!!!

You say it lags at 2000 - 2500 RPMs, My F4i idles higher than that when cold! I don't even know how you can get on it at those RPMs unless you are trying to run a 1/4 mile and IF that were the case you would have it reved higher than that in anticapation of the launch!

So my question to you is WHEN do you actually see this problem and what are you doing to bring it out? racing the mustang sitting next to you at the light????

[badazz 1K]

also if you are doing this in nuteral (as you said "When the bike is just idling, and you WOT fast, she sputters, then revs up, then sounds like she is going to die out") did you ever think that maybe you just have dirty injectors? You spent money on things that have zero to do with your problem, good job. hope you kept the other parts for spares as I'm sure there is nothing wrong with them.

[slickwill]

When the bike is just idling, and you WOT fast, she sputters, then revs up, then sounds like she is going to die out.

I have an F4i and it sure doesn't do this so it still isn't normal. From the way he says it I don't think he is meaning it is in gear at this point. Yeah, mine idles higher than that when it is cold, but it warms up in less than a minute and settles in right at 1400rpm like it is supposed to. Like others said a PC might help but it would be covering up a problem. There shouldn't be a lag there.

[badazz 1K]

who actually WOTs the thing in netural? Have you... all the way? I've reved mine no doubt but WOT????? I don't believe I have ever done that in netural.

[Twincam]

Pardon me for sounding stupid, but can someone explain what WOT is?

Thanks

[slickwill]

Wide Open Throttle, and I'm going to give him the benefit of the doubt by believing that he isn't exactly pinning it. I've dealt with plenty of engines over the years that if you gently add some fuel they will smoothly rev up. However, if you then crack the throttle open they will bog before they go. So I'm sure I know what he means the problem is. I'm just not sure what to fix on his bike. On a carbureted engine that is often an issue with a low speed needle. On a fuel injected engine I have had it be an issue with the fuel filter, ECM, ignition system, etc. It could be a lot of things. I would check fuel filter and throttle position sensor.

[Twincam]

Originally Posted by slickwill

Wide Open Throttle, and I'm going to give him the benefit of the doubt by believing that he isn't exactly pinning it. I've dealt with plenty of engines over the years that if you gently add some fuel they will smoothly rev up. However, if you then crack the throttle open they will bog before they go. So I'm sure I know what he means the problem is. I'm just not sure what to fix on his bike. On a carbureted engine that is often an issue with a low speed needle. On a fuel injected engine I have had it be an issue with the fuel filter, ECM, ignition system, etc. It could be a lot of things. I would check fuel filter and throttle position sensor.

Thanks for that, and yeah i do understand what you mean

[vietladin]

Yes, please let me clarify. When the bike is just parked and in neutral, I WOT it for about 2 seconds. It sputters, then revs hard, then idles like ****, and most of the time dies out. Right after that, I have a hard time starting her back up. On the other hand, when I slowly roll the throttle, she revs up perfectly throughout the power band, and doesn't die out, when she goes back to idling. Anyhow, i'm going to go to Honda tomorrow, and have them diagnose it. I don't want to spend anymore money on parts, that don't need to be replaced. At least I have a almost new bike, with all the parts that I already have replaced.

[Ammocbr]

Just a thought...Seeing as you live a very humid area do you think you might have some water in your fuel system? That might replicate the same problem. I've seen it in many small block chevy's and numerous other vehicles. I've also seen the problem with timing being off.