89 1200 with V&H pipe and K&N filters

[RobbieKNobbie]

I just bought a 1989 FJ1200 which the previous owner had installed V&H full pipes and individual K&N pod filters. The sound is throaty and not too loud, so I'm ok with that, but I'm a little disappointed with the low end and midrange power. Am I correct in assuming that these intake/exhaust mods are to blame? The carburetion feels pretty good, no flat spots or stumbles worth mentioning, it just doesn't have that low end PUSH that my 1200 Bandit has. Am I expecting too much, or do I need to track down an original airbox and back out of some of these 'performance' mods?

Your thoughts and experience appreciated!

[retcol]

Contact the seller and ask him/her if he/she had installed a stage 3 jet kit in the carbs. Could be you are running stock carbs and with those pipes and filters, the bike will not performance very well. If they did rejet the carbs, it could be something else then. When I added Muzzy pipes, individual filters and a stage 3 jet kit on my ZRX1200, it ran like a rocket ship! It sounds as your bike is not getting enough fuel, running too lean due to jetting/needle adjustment.

[Pat Conlon]

Yep, jetting
Remember, the USA FJ's were set lean to begin with (thank you EPA) now with the pipe and pods, you've increased the volumetric efficiency allowing more air thru the engine, which makes an borderline lean condition worse.
Run #42 pilots (USA stock is 37.5) raise the the needles 1 step and put in some 117.5 mains.
If you don't have adjustable needles (USA bikes did not) you could try raising the needles with special needle shim washers (RPM) but that will only get you 1/2 step not a full step. Personally, I would invest in some adjustable needles.
Your FJ should pull like a train, if not, something's wrong.

Hope this helps.

[RobbieKNobbie]

Pat,

Having ridden the bike a few miles now, I can say that somewhere along the line someone did take a swing at the carbs, but I don't think it's running as well as it could... from about 3-3.5k on up it pulls very well... not so much like a train, but like a reasonably healthy late 80's litrebike. To be honest, I was expecting a little more from the bike known for the best roll-on times of its decade.
There is, however a noticeable stumble/surge that goes on between 1500 and 2k that makes me think that the jetting is not optimal. Not that I putz about at 1500rpm all day, but it is there at low speed take offs and when dealing with slow stop-and-go traffic on a clogged freeway.

I have not removed the carbs yet, but a few days after I got it, I looked in and found 2 of the K&N filters had fallen off (I think I may have mentioned this in another post?). The filters are offset tapered ovals, and if you try to put them all with the carb ports at the top, the two outside filters will not fully 'grab' the carbs. The solution I used was to 'invert' the offending filters , so they were sticking up above the carb throats. This allowed them to clear the frame rail and mount much more securely. They have not fallen off yet. The point of this story is that the absence or presence of the two filters made no perceptible difference to how the bike runs. Whatever that's worth.

I'll dig into the carbs this winter when I pull the bike into the shop and do everything else. For the rest of the autumn though, I don't have a lot of time to mess about with an otherwise good running bike.

I appreciate your suggestions for replacement jets, I'll definitely keep that in mind for later in the year. While I consider myself a half assed competent wrench, I admit my limitations when it comes to carburetors!

Retcol: no dice... the previous owner knew nothing about the bike. Middle aged dad-type, apparently he bought it from a buddy, had no street riding experience, put 400 miles on it over the course of 3 years and left it in the corner of his garage the rest of the time. From seeing his garage (very Dodge/mopar oriented mancave, no other m/c stuff at all) and talking to him for a while, I believe his story of relative ignorance for the bike.

Cheers!

[Pat Conlon]

Yes, I remember you lamenting about the K&N pods, and I remember our advice to you about them.
That's the beauty of not having the air box, you can remove, rejet and replace the carbs in 1 hour, 2 hours working very slow. It's the carb cleaning that takes time, not changing the jets.

I would not wait. Fall is a beautiful time of the year to ride, and life is short.

[Country Joe]

I would not wait. Fall is a beautiful time of the year to ride, and life is short.

Very true and very well said, Pat!

[RobbieKNobbie]

I would not wait. Fall is a beautiful time of the year to ride, and life is short.

Very true and very well said, Pat!

Oh trust me guys, I'm riding the FJ every chance i get... Unfortunately back and forth to work is about I have time for right now. If i had a spare hour or two to pull the carbs, then i have an hour to get a customer's job out the door.

Things always slow down late november or december though...