Re: Recommended Jetting

[Flying Scotsman]

What jets etc should be in my 85 FJ1100.As far as I know its only mod is the air box is removed.I think that the way it has been runing the past owner didnt rejet when he put the pod filters on.Carbs might be way out of sinc but I might as well take a look at the jetting and see if its right.

[SlowOldGuy]

Factory jets should be adequate, but you definatly need to shim the needles.

DavidR.

[Flying Scotsman]

Never worked on this type of carb what way do I shim them.Should I buy a kit with adjustable needles.

[Flying Scotsman]

She has a dynojet kit in her.I think I am rich but running quite good.I need to fix a pinhole leak in the carb slide diaphragm before I do anything else.I went to there website for 1985 fj1100 and set up per there recomendations.

[RichBaker]

What do you have in her now? Where is the clip on the needles?

[Flying Scotsman]

Found out I have a Kerker 4-1-2 exhaust on her.
I have the clip in the top slot now I still think I am a little rich but she starts easy idles great and  runs smooth at any throttle position.Runs great compared to when I bought her.Still seems a bit lazy at lower rpm's.

[fj1289]

Scott,

I'd recommend lowering the clip 1 or 2 grooves (probably will end up in the middle groove or the one above it) and see how it responds.  The laziness at lower RPMs is probably being lean on the needles. 


Chris

[Flying Scotsman]

Chris,I did try raising the needles and it got worse.My mpg now is 30-32 mpg when I tried the second or third slot.I saw as low as 24 mpg you could smell gas in the air big time.I need to measure the float height I know there all even I just need to see where there at and  check what jets are in there.(If I can figure out what each jet is).I need to see if its jeted for a pipe.I may have to jet her different than they say for a pipe because my pipe is a 4 into 1 into 2 so its a lot like the stock pipe but different.After I lowered them the first time I went back and raised them to make sure I was going in the right direction then lowerd them again.
I can blip the throttle and return to idle no problem and my choke works as it should.I think im real close and all I need is a few degrees of timing to wake her up.I need a new chain mine is stiff in spots that might be hurting mpg and I have a weird shift patern because I need 2nd and 3rd gear fixed so my trans might be costing me mpg too.I hear 40 mpg is do able I would be happy with 35 mpg.FJ is running good I think she can run a little better thats all.

[fj1289]

Sounds like you are in the hunt.  Since you already know you're rich with the clips in the top groove, lowering the float heights sounds like a good move.  You may have to adjust the idle and needle afterward, but I'll bet it gets you where you want to be.  I'm sure that 4-1-2 pipe flows at least as well as any 4-1 - you've got twice the muffler volume so it should be LESS restrictive! 

[WestOzFJ]

How many miles on the emulsion tubes? What needles are in? Should be a part number on the needles. Sounds like maybe tubes could be worn over size.

My pods equipped '87 was a DOG to ride down low. So I re-built the carbs off my airbox '86 and transferred to the '87....

I suspected these emulsion tubes are worn as the '86 ran rich in the mid range (yet the needles are standard) and I wanted to find out how the pods engine responded with this fatter mid range set up BUT also changed to a different main and pilot jet combination - both engines have the same 4 into 1 and I always run 98 octane fuel.

I believe it's accurate to summarise the pods differing fuel curve requirement by saying; individual pods interfere with the idle vacuum signal's interaction with the pilot fuel circuit whilst the airbox with it's effect of signals from all 4 cylinders dampening the pulses (so to speak), therefore the pods and the pipe seems to require 1 step richer on the pilot jet (which made a massive difference to driveability) YET a very similar to standard needle position and slightly richer top end/main jet.

I drilled my pilots from the 1200 standard #40 to one number drill size up which dropped my fuel/air screws back into a tuneable range.

It's recommended to select the correct main jet first because this will change the needle/emulsion tube requirement - if you decide to go "fine tuning" the main jet later then you'll be back to re-covering old ground with the low to mid range tuning...

As a footnote, after I got the carbs on and running well, (only this week) I modded the ignition baseplate to run an extra 5 degrees of timing which did soak up some of the richness and made the engine sharper - especially in the 2000 to 3500 rpm range.

Hope that all helps.

Victor.

[Flying Scotsman]

Sounds like you are in the hunt.  Since you already know you're rich with the clips in the top groove, lowering the float heights sounds like a good move.  You may have to adjust the idle and needle afterward, but I'll bet it gets you where you want to be.  I'm sure that 4-1-2 pipe flows at least as well as any 4-1 - you've got twice the muffler volume so it should be LESS restrictive! 

Thanks for helping me I dont think the float height will make a big difference but its worth checking.
Thanks for helping me think this through

[Flying Scotsman]

How many miles on the emulsion tubes? What needles are in? Should be a part number on the needles. Sounds like maybe tubes could be worn over size.

My pods equipped '87 was a DOG to ride down low. So I re-built the carbs off my airbox '86 and transferred to the '87....

I suspected these emulsion tubes are worn as the '86 ran rich in the mid range (yet the needles are standard) and I wanted to find out how the pods engine responded with this fatter mid range set up BUT also changed to a different main and pilot jet combination - both engines have the same 4 into 1 and I always run 98 octane fuel.

I believe it's accurate to summarise the pods differing fuel curve requirement by saying; individual pods interfere with the idle vacuum signal's interaction with the pilot fuel circuit whilst the airbox with it's effect of signals from all 4 cylinders dampening the pulses (so to speak), therefore the pods and the pipe seems to require 1 step richer on the pilot jet (which made a massive difference to driveability) YET a very similar to standard needle position and slightly richer top end/main jet.

I drilled my pilots from the 1200 standard #40 to one number drill size up which dropped my fuel/air screws back into a tuneable range.

It's recommended to select the correct main jet first because this will change the needle/emulsion tube requirement - if you decide to go "fine tuning" the main jet later then you'll be back to re-covering old ground with the low to mid range tuning...

As a footnote, after I got the carbs on and running well, (only this week) I modded the ignition baseplate to run an extra 5 degrees of timing which did soak up some of the richness and made the engine sharper - especially in the 2000 to 3500 rpm range.

Hope that all helps.

Victor.

I will look at the needles for a # next time im in there to check everything out.The guy I bought the fj from didnt even know how to take the seat off and he only had it a few months  so I dont know when the emulsion tubes went in there.I am sure 5 deg of timing would be a big gain on my 85.
Thanks for helping I am still learning these carbs.

[WestOzFJ]

Reading some of the other members' previous posts on the subject, there's a difference between 1100 and 1200; needles, emulsion tubes and slides. So it's not inconceivable a mismatch has occurred in previous "tuning and maintenance"...

And hey, there's some really great carby description and tuning manuals in the library which made it a breeze to understand a carby type that I sure as heck never worked on before either....

Victor.

[fj1289]

Sounds like you are in the hunt.  Since you already know you're rich with the clips in the top groove, lowering the float heights sounds like a good move.  You may have to adjust the idle and needle afterward, but I'll bet it gets you where you want to be.  I'm sure that 4-1-2 pipe flows at least as well as any 4-1 - you've got twice the muffler volume so it should be LESS restrictive! 

Thanks for helping me I dont think the float height will make a big difference but its worth checking.
Thanks for helping me think this through

Well, if you have the idle right, and you're rich at low throttle settings, and the clip is on the highest groove of the needle, and you have a free flowing intake and exhaust, I'm out of ideas to lean it out otherwise (other than emulsion tubes, but I'd figure it's better to recommend a free adjustment before $100 parts swap).

Good luck.

[Flying Scotsman]

I have heard of shorter and longer needles I wonder if I have short ones.How long are factory pro needles compared to Dynojet needles ?.And are the emulsion tubes where the needle slides in ?