From F4 to F4i

SilverbirdXX · 09-19-2007, 1:42 PM

I've had it with the carbs on my F4. Everytime I ride it's something different. It's the best handling trackbike I've ever had. It will be expensive and a pain to switch to an F4i, will it be worth it? Is the Fi pretty much trouble free?, especially when changing altitude without a map change?

Got Fast? · 09-19-2007, 1:54 PM

I have an F4 as well an I can relate the carbs are a bit of a hassle. My friend told me this when I was griping. The F4 is the best carb technology beeing the last of its kind, and it really is. I don't know how much trouble yours is giving you but personally i like mine just due to ease of maintenance and simplicity. True enough though Fi is much better.

slickwill · 09-19-2007, 2:40 PM

I bought my F4i because of the Idaho and Iowa cold weather. All of the carbed bikes I've ever had were always a pain to start and never seemed to run like I wanted.

Now warm or cold I walk out to the garage and turn the key, no choke, no fuel petcock, no hassle, automatic high idle. I still always let it warm up until the temp is registering before I ride away from my house but that is more for oil pressure and longevity rather than fueling. The FI also has auto enriching and many other nice features that you don't get with carbs.

As far as worth it or not, that is up to you.

I'm extremely happy with my bike.

Edit: just noticed you asked about altitude. FI can adjust pretty well to altitude changes based on information from the MAP sensor and O2 sensor. You will still notice a power loss as you climb those Colorado mountains but your bike won't be running rich because of it. On a carbed bike as you gain altitude and lose atomospheric pressure your carbs can't adjust and still pour in the same amount of fuel. The FI can read that it is getting over rich for the available oxygen and will cut the fuel delivery to maintain the mixture. I've had some fairly powerful cars on top of those CO mountains and there isn't much power left at 10,000ft.

Got Fast? · 09-19-2007, 5:21 PM

F4 doesn't have a petcock unless Ive overlooked something very important. For me it ussually doesnt make a difference I live in california so cold weather is rare. When it comes to riding the cold start takes me all of a minute for warmup. I have however ridden it cold and it definetly is more finicky on launch
.

I have been waiting for this Emoticon all my life.

*Fastrr* · 09-19-2007, 8:40 PM

Well F4 is a 2000 model year correct? So it's 7 years old or there abouts. Time to rebuild the carbs with new oem Honda gaskets and seals. Replace the enrichment valve seals also.. trust me. What's wrong with the way your F4 runs probably has a lot to do with carbs need to be gone thru and rebuilt about every 4-5 years. It's going to cost around $250 just for the parts, but it's money well spent. Also replace the air filter, fuel filter and spark plugs all at the same time. Have the carbs synchronized by a professional or if you understand carb synching d.i.y.

I'd say just pay the $500, take it to a shop that can fully rebuild the carbs and synch them. You'll love how it runs when you get it back.

slickwill · 09-19-2007, 9:06 PM

Quote:

F4 doesn't have a petcock

Didn't know for sure, but most carbed bikes do and I can't for the life of me remember to turn them off and on. I can't count how many times I've been riding my FZR or CR and had it suddenly die due to "lack of fuel." On the CR it always leads to excessive kicking to get the fuel pumped through again. My next dirt bike will be FI also.

Red Rider · 09-20-2007, 8:16 AM

Since you mentioned track bike, you really should consider a 600RR. The difference in handling over an F4(i) is like night and day on the track...

Got Fast? · 09-20-2007, 12:56 PM

I remember hearing that the F4 fuel shut off was transistorized or something because I have looked and there is nada. Again unless im missing something really big.

*Fastrr* · 09-23-2007, 3:24 PM

Here's some links to rebuilding and cleaning the F4 carburetors if your interested. on this link there are more links to F4 carb work. And maybe with a little luck the the administators of this website won't delete or edit my post this time.

Honda CBR F4 Carburetor Cleaning

SilverbirdXX · 09-24-2007, 10:28 AM

I did all the cleaning, it's even been dyno'd. F*&^ carbs.

I came across an old article that complained about the i having a narrow powerband compared to the F4, that the 8-10K power burst was gone on the i model and not made up for in 10-12K range. Please tell me I won't miss the F4's power characteristics.

slickwill · 09-24-2007, 10:39 AM

I feel like 8K is right where mine starts to come alive. It is also where the front wheel will come up if I want it to. This is Sport Rider's dyno for the '01 F4i. The injection was improved for '02 and they added one tooth to the rear in '01 compared to the F4. I have no complaints about the power delivery on my '02.

slickwill · 09-24-2007, 10:47 AM

Here is a good F4i review.

2001 Honda CBR600F4i: MD Ride Review

Sport rider also had a feature where they compared the F4 to the F4i and they said that it didn't matter where you were on the track the F4 could at best hang near the F4i but that in almost every case the F4i could pull away. I think the newer F4i's have been slightly "softened" compared to the '01 and '02's though.

SilverbirdXX · 09-24-2007, 11:49 AM

They improved the fi in 02'? Most of the bikes for sale seem like they are 01's. Would it be worth finding and 02' since that's the main reason I'm going through all this trouble?

slickwill · 09-24-2007, 11:55 AM

Quote:

Originally Posted by SilverbirdXX

They improved the fi in 02'? Most of the bikes for sale seem like they are 01's. Would it be worth finding and 02' since that's the main reason I'm going through all this trouble?

The Sport Rider thing that I read said that it was a minor remap to fix some issues that they had on the '01. It was their first year for FI so I would imagine that there was room for improvement. However, I would think that if you were going to add a PCIII then you might be able to make up the difference on your own. I'm not sure, I'm no ECU expert and can only say what I have read.