what size main jet?

[HARTLESS]

Negative ghost rider. Any cone airfilter in a car needs oil, don't know where you got that from. Paper particles have microscopic gaps which can let crap in, hence the oil to keep them moist and close the gaps. Dry paper=uh oh!

So you close up the gaps with oil, how does the air get in?

You don't oil ANY paper filter.

you caught me. To brief. Not necessarily did I mean seal the thing completely, but keeps it moist and sticky and not dried out and brittle. As described before there is gasoline mist that isn't good for them

[thunder1295]

Damn looks like I'm going to only oil 2 of the pods, no one seems to agree on this subject..LOL

Anyways back to the jetting, I went to a local bike shop that does big bore's and rebuilds, you name it they do it, dyno bikes and I got to talking with the guy's up there and they suggest I go with 125 main jets on cylinder 1&4 and 122.5 on cylinder 2&3, right now I just have the 4 single pods on the carbs, the rest of the jets are stock and the needle is on the middle slot. Well I'm happy to say the bike goes like stink, my midrange is back  and once I get to 7 grand it pulls like crazy, purrs of the line and no stumbling or farting anywhere., have my stubby can's coming Fri, so I'll see if that changes anything.
I just did a ride about 120 clicks and I'm pleased with the mileage, didn't really notice a diff.

Jim

[ribbert]

Damn looks like I'm going to only oil 2 of the pods, no one seems to agree on this subject..LOL

Jim

There is nothing to agree or disagree on here. You do NOT oil paper filters, not even a light mist. I believe the confusion is with the third type of air filter, cotton gauze. These are made with a pleated design the same as paper filters and to the casual observer look the same and are common with aftermarket filters. The difference being you oil the cotton ones but not the paper ones.

Noel

[HARTLESS]

Damn looks like I'm going to only oil 2 of the pods, no one seems to agree on this subject..LOL

Jim

There is nothing to agree or disagree on here. You do NOT oil paper filters, not even a light mist. I believe the confusion is with the third type of air filter, cotton gauze. These are made with a pleated design the same as paper filters and to the casual observer look the same and are common with aftermarket filters. The difference being you oil the cotton ones but not the paper ones.

Noel

yup. that confusion is my bad

[fjpaul802]

different size jets on 1&4 and 2&3?? I have never heard of that. But then again  I dont know shit about these bigger motors. I just got my fj and re-jetting the carbs is one of my first priorities. I guess I should just order a pair of 122.5s and 125s. has anyone else tried this combo??  I just was thinking that the difference could cause possible stress on the crankshaft and possible damage to the motor. Anyone out there who actually knows what their talking about? I would appreciate your input

[Arnie]

There are quite a few here that know what they're talking about, you just have to decide which of the responders they are. :-)
Those jets, if they are Mikuni jet numbers are way too large for any FJ engine that is close to stock.  While you might find the need to have differing sized jets in an engine, the middle cylinders are amost certainly the ones that need the larger ones.  It is unlikely that you'll damage your engine with these oversize jets, but you won't make more power, and will use more fuel with them installed.  Do proper plug chops and then decide what if any jetting changes you need.

Arnie

different size jets on 1&4 and 2&3?? I have never heard of that. But then again  I dont know shit about these bigger motors. I just got my fj and re-jetting the carbs is one of my first priorities. I guess I should just order a pair of 122.5s and 125s. has anyone else tried this combo??  I just was thinking that the difference could cause possible stress on the crankshaft and possible damage to the motor. Anyone out there who actually knows what their talking about? I would appreciate your input

[FJmonkey]

I am running the RPM recommended main jet at 112.5, I have UNI pods an SupperTrapp slip on exhaust. They seem to work quite well with the needles up one clip. Runs like stink....

[Dan Filetti]

I am running the RPM recommended main jet at 112.5, I have UNI pods an SupperTrapp slip on exhaust. They seem to work quite well with the needles up one clip. Runs like stink....

And Mark get's like, 92mpg too... 

[FJmonkey]

I am running the RPM recommended main jet at 112.5, I have UNI pods an SupperTrapp slip on exhaust. They seem to work quite well with the needles up one clip. Runs like stink....

And Mark get's like, 92mpg too... 

Dan, I am falling off my chair 

My AVG is 44.6 for the WCR, over 1400 miles over 4 days. The Monkey is the MPG envy with Kookaloo....

[RichBaker]

The stock paper filter does NOT need oil..... Just like a car filter. Oil will make it more restrictive.

Negative ghost rider. Any cone airfilter in a car needs oil, don't know where you got that from. Paper particles have microscopic gaps which can let crap in, hence the oil to keep them moist and close the gaps. Dry paper=uh oh!

I said STOCK!!!! NOT A STUPID CONE FILTER!!!!!!!!!!!!!!!!!!!!!!   Do we have an IGNORE function on this forum??

[RichBaker]

There are quite a few here that know what they're talking about, you just have to decide which of the responders they are. :-)
Those jets, if they are Mikuni jet numbers are way too large for any FJ engine that is close to stock.  While you might find the need to have differing sized jets in an engine, the middle cylinders are amost certainly the ones that need the larger ones.  It is unlikely that you'll damage your engine with these oversize jets, but you won't make more power, and will use more fuel with them installed.  Do proper plug chops and then decide what if any jetting changes you need.

Arnie

different size jets on 1&4 and 2&3?? I have never heard of that. But then again  I dont know shit about these bigger motors. I just got my fj and re-jetting the carbs is one of my first priorities. I guess I should just order a pair of 122.5s and 125s. has anyone else tried this combo??  I just was thinking that the difference could cause possible stress on the crankshaft and possible damage to the motor. Anyone out there who actually knows what their talking about? I would appreciate your input

Go too rich, and there is a possibility of washing the oil off the cylinder walls, and that WILL damage a cylinder....

Some of us DO know what we're doing, but there are enough idots that THINK they know better giving very BAD advice.

RPM Randy KNOWS his stuff, as do several others on here.

[thunder1295]

Ah, ya that's Canadian, lets not get into name calling here,  I'm just telling you what they told me and Im sure they know there shit.
Yes the bike is running way better then stock jets, I can't see going up from 110 to 112.5 going to make much of a diff. when 110 are with a stock air filter and what the diff with the air restriction using pods?
After looking at other big engine bike, yes they are all diff. but they are running main jets all the way up to 132 and average around 128..
Anyways I don't want to get into a pissing contest here, I just passed on what they told me to do and it work on my bike.
They been in business for sometime so I'm sure they know what there talking about or they wouldn't be around.

Jim

http://www.cycleimprovements.com/

[Bozo]

I'm not going to say who is right and who is wrong but when I had a stock motor with K & N filters (cleaned and oiled using K & N filter cleaner) I ran 110 mains needle clip up slightly (2 x 3mm washers add underneath)all else was standard.
After fitting a piston kit with higher compression, street cams and a 4-1 exhaust - mains 112.5, pilot 42.5, air jet standard and the needle third slot from the top (leaner) BBBUT it is cooler in Perth at this moment so during summer I expect the mains/ needle setting to change (at present the bike pulls very well at all revs and plugs look good). Also I now have uni filters.

Remember Perth (Australia) is not far from sea level so if you live higher the settings will change.

As Arnie stated check the plugs and if you run different jets the two inner cylinders would need the larger jets as they run hotter.

I suggest you slowly go down in jets till the plugs look good and the performance is good (or most likely even better). Good luck.

You are correct some bikes run 132 mains (my Kawasaki Z1R does) but don't compare other bikes and makes with the FJ.

[ribbert]

they suggest I go with 125 main jets on cylinder 1&4 and 122.5 on cylinder 2&3,

Jim

Firstly, as Arnie said, the bigger jets would go in the middle. Their suggestion is based on a generalisation that 4 cyl, air cooled in line motors run hotter on the middle 2 cyl's.

The FJ's, for reasons I've mentioned here before, appear to be an anomaly with the ducts forcing air directly down on the centre of the middle cyl heads providing better placed cooling than the outside cyl's.

The fact you say your bike goes like the clappers is only relevant if you have a benchmark. We have occasionally had people here in awe of the FJ's power when they first get on it only to discover later it's running on 3 cyl's or has chronically slipping clutch or some other performance inhibiting issue.

Jet size and bent crankshafts aside, their suggestion is true in theory but has little or no merit in practice, particularly on a road bike.

The FJ's tuning parameters are very generous before a significant change in power will be noticed and while running 2 different jet sizes won't harm your motor, neither will it improve it's performance, IMO.

A plug chop, as Arnie suggested, should answer this, if everything is as it should be I think you will find the plugs are all the same.

"They been in business for sometime so I'm sure they know what there talking about or they wouldn't be around." - not necessarily!

As has already been covered by a few people, but I will say it again. There is a staggering amount of FJ experience, general mechanical expertise and peripheral knowledge here.
If I was looking for information and had the choice of the collective knowledge of this forum or the local bike shop that "knows their shit" it would be a no brainer ( err, that would be the forum)

Noel

[jscgdunn]

  Thumbs up on your comments Noel.... My observations:
This forum ranks as one of the best;  in my experiance another very good one is the boats.net mercury outboard forum for the carb motors.  I think the reason that these these two are so good is because in both cases the power plants (mine is a 200 BlackMax) have been around along time and have been used for racing.  The reason for that is because they are engineering marvels.  There are real racers on both fourms who really know their stuff and have a great interest in getting "newbies" up and running.