FJR1300 05 gen2

[dougindoors]

Well today I set up the balance gauges and the bodies were well out no.3 was really low and out between 1-2and3-4. I checked the balance from cold noting if there was any changes as she warmed up, this was all done with the air screws right in and the main idle air screw backed of, when hot was idling at 1200 even with the main idle adjuster backed out. To get 3 and4 right the butterfly screw is screwed right down same thing on the screw for 1-2 and 3-4 readings about 230-240 but now idling just under 2000 rpm, squeezed all the vacuum hoses on the bodies no difference apart from the one to the vacuum sensor that stalled the engine, the cold start is not hanging up, I have also had a good spray round for vacuum leaks none found. any pointers? Runs sweet but a tad to fast, time to remove the bodies again for a nosey? I dont know

 

[audiowize]

What kind of balance gauges do you have? Before using them, it's nice to use some "T" fittings and some extra hose to plumb all the gauges to the same vacuum port so that you can check them against each other (you can also use a mighty vac for this purpose). Otherwise, gauge consistency can have you chasing your tail.

 

[dougindoors]

I use a bank of 4 dial type gauges and as you say I always check each one on one cylinder to confirm the same readings.

 

[dougindoors]

I did say vacuum was low, its not its high sorry for misleading every one 1,2.and 4 read10" vac and 3 reads 15" vac idle speed is 1300rpm and can not be lowered, the rest is in the original post

 

[audiowize]

Have you started by adjusting #3 to 9.8" Hg? Generally, you are supposed to attempt to get 9.8" Hg and ~1000 RPM idle at the same time.

 

[dougindoors]

I cannot get the idle down to 1k that's the problem, had a play tonight all gauge needles level and raising and lowering together but still at 1200-1300 rpm idle. I did find if I force the twist grip to close the butterfly's I can get it down to 1k but number 3 goes out of balance until I release the twist grip and the rpm goes back up. I think there's a problem with the throttle bodies, or at least number 3, the history on this bike is the cct failed took out all the valves, I bought it off a pal after the bike shop fitted a new chain and cct, then told him sorry you have no compression, when I purchased her she was still stripped, so I was left to change the head for a used low miler and put it back together from a box of bits, starts and runs sweet no noises of smoke, just won't tick over at a 1000 rpm.

 

[audiowize]

OK, this is good information. I suspect that you have butterflies that aren't well synced up. If a couple of them are open too far, then your RPM will always be too high, and the vacuum measurements/idle screw adjustments will be worthless at idle.

There are throttle stops between throttle bodies 1 and 2, as well as 3 and 4. The throttle should close and hit all of these at the same time, and this would be the next think that I'd check. If one has been adjusted on accident, this could keep your idle too high.

With the idle speed adjusting knob all the way down, you should adjust and even out the idle stop screws to get a low idle of 750 RPM, then you nudge the idle up with the little adjustment wheel by the clutch cover.

If you can get to here, then you can set the vacuum on #3 and balance out the rest of the air screws. Some folks will progress on from here to balance the butterflies at 4000 RPM, then go back and re-balance the air screws at idle after this procedure. With what you're describing, getting the idle set properly seems like a higher priority. (Note - if you've mucked around with the butterfly screws and the air screws, it would be worth mentioning that)

 

[dougindoors]

Thanks audiowise just before I read your post I put more slack in the pull cable on the aduster by the twist grip and set the centre aduster screw and the 3-4 screw midway now the butterfly's are hitting the stop screws, thought I would mention my main idle adjustment is not mechanical it is an air screw as on the later models, you refer to 9.8 Hg my gauges only show inches vacuum or mm vacuum do you know what that would convert to is that 9.8 inches? that's what happens when Europe try's to take over lol. Dammed metric.

 

[audiowize]

It's damn near 100mm.

I wasn't aware that any pre-Gen3 FJR's didn't have the idle adjustment screw, I would be concerned that you may have a throttle body rack off a gen3 by accident.

 

[dougindoors]

No it's correct I have the 2005 supplementary manual which covers this and other uk updates for 2005

 

[mcatrophy]

... you refer to 9.8 Hg my gauges only show inches vacuum or mm vacuum do you know what that would convert to is that 9.8 inches? that's what happens when Europe try's to take over lol. Dammed metric.

"9.8Hg" means "9.8 inches of mercury". It is the same unit, more simply expressed.

Or, of course, 9.8 x 25.4 = 248.92 mm of mercury.

You can translate that into other units such as 0.332 bar, 4.8 psi ...

 

[audiowize]

No it's correct I have the 2005 supplementary manual which covers this and other uk updates for 2005

Hmm, there's also the wax motor that keeps the idle high when cold, have you observed it actuating before moving along to set the idle?

 

[dougindoors]

Yes the cold start is coming off, tonight I had another go got the idle down to 1100 rpm but 3 reading ok but 4 would not balance without rpm raising and could not get 1-2 to balance with 3-4 unless the rpm went up. I have just purchased another set of bodies from El Paso USA at a good price from a 2007 with 37 k let's see if they make any difference, if not she's running fine I'll sell and keep the vmax she don't give me any trouble, lol.

 

[audiowize]

If the RPM's go up when you balance, that's not necessarily the end of the world, you may just need to lower the idle more.

 

[dougindoors]

I think I must be missing some thing, no air leaks, clearances done, was running fine before the cct let go, so what has changed, maybe I'm barking up the wrong tree, would 1 tooth out on the valve timing give this fault. Now I'm no doubting my own work, was checked and triple checked on assembly.

 

[dougindoors]

Going back to the beginning throttle bodies off waiting for the replacements, having a set of blanking plates made to remove the air system, so while I'm there off with the rocker cover and recheck valve timing and clearances, researching things a high vacuum reading on one cylinder points to that cylinder is Beining carried by others and not working as hard, possibly a tight clearance? Well all will be revealed. I could sell it as is and bodge the idle speed by adjusting the throttle stops, but I could not live with that knowing I was selling it with a problem.

 

[RossKean]

The cylinders should be balanced via the air screws. However, you can achieve the balance with almost any starting point on #3. If the starting point is "off" by too much, you will find that you don't have enough range in the idle adjustment to get the idle speed where you want it.

Redo the TBS. Gently screw all the adjusters in until they are lightly seated. Open all of them about 3/4 of a turn and then start to balance. Don't worry about the initial vacuum and don't worry about matching everything to #3 (or any other). If you can't get a balance, you might try starting with one full turn out.

Obviously, you need to make sure that the air passages aren't blocked and that you do not have a vacuum leak somewhere.

Good luck.

 

[dougindoors]

Pulled her apart again valve timing and clearances ok, so must be a prob with the throttle bodies, wait for a replacement set, next week I hope unless customs hold them up, coming from El Paso to UK.

Cheers ross

 

[dougindoors]

New throttle bodies on and all is well, running like a Swiss watch.