Trouble Getting Going

[ChrisK]

I'm going to try it out again today. It's 20 degrees warmer than it was last night when I was testing, so I may actually be right where I need to be.

If I'm not, I may try switching back to my original 60 slow jets, and tweaking from there. If that seems too rich then you're right Koko, I may need to order 57's or 58's, whatever they come in.

I still haven't had an opportunity to cruise at highway speeds. I've ran it up that far, but it wasn't exactly legal...    I'd like to get on a highway, cruise along, and see how it performs. As well as how it decelerates and pulls from highway cruising speed.

[ChrisK]

Screwed the air screws in an 1/8 turn. Bike immediately started at push of button after a slight twist of the throttle. Stayed idling too.

Ran alright across town to lunch, but when I got here and was backing into a parking spot, it died on me at idle.

Edit: Yeah it's still not running great. Will die at idle, seems like after the bike is warm? Still feel some stumbling at cruising speed.

This is the thing I'm worried most about: Seems like when I take off from a stop there is a pretty bad vibration from the bike and a rattle noise from the air box vicinity. What does that mean?

[Rudemouthsky]

I've never seen anyone have this much trouble getting FCR's to behave reasonably well out of the box. Bike ran good before?

[ChrisK]

Yeah, it's getting pretty frustrating for a $900+ investment.

Yes, the bike was running good before the FCR's, but I've had so much bad luck with it, some caused by me some not. Right before winter the rectifier went bad, that's been replaced. Over winter I lightened the flywheel. When I put it back in to test (before FCR's) I made a mistake reinstalling the starter clutch. The bike ran beautifully before that mistake showed it's face. That's all been fixed since. Most recent was the first half of this thread: broken wire at the ignition pickup and then me having to reset the timing.

[ChrisK]

After work today I tried the following setup:

6th needle clip
165's
55's
4 turns fuel
7/8 turn air

Okay results, but still died at idle after being warm. Also a friend said he smelled a rich smell while riding behind me taking off from an intersection, and maybe once in the highway.

My most recent try:

4th needle position
165's
52's
2 turns fuel
1 turn air

The bike didn't die at idle, but idle didn't sound very good either. Very choppy. At highway speed there's still that raspy, whistly noise from the airbox. Cruising at 35 in 3rd gear I can consistently feel a hiccup in the performance.

I still have that very fast vibration right when I takeoff. It happens very noticeably in 1st at the point of dropping the clutch, and I can feel it a little going from 1st to 2nd. It's very brief, but it's there and it feels terrible.

Please, anyone have suggestions?

[Speeddog]

Off the top of my head, stop changing 4 things at once.
Change one setting at a time, and see what it does.
Write down the settings, change one thing, write down the results.
Then try another change, continue writing it down as you go.

And I don't think leaner is the direction you should go.

[koko64]

Speeddog is right, one change at a time.
I believe that rich smell your buddy noticed is the No#6 needle position (oh and 4 turns out on the idle mixture with a rich SAJ setting). Sheesh, one change at a time .

Ok, go back to a baseline and change only one thing at a time from there (after this  ).
Try this setting and only change one aspect after that, remembering to write it down.
Keep the 165 mains
#5 on the needle
try 1 1/2 turns on the slow air jet screw
Try your 60 slow fuel jet.
1 turn out on the Idle Mixture Screw
Write it down.

Now we need to settle on the Slow Fuel Jet, and we will know by your idle mixture setting. Try and tune the idle only with that idle mixture screw. Go for the fastest, strongest idle and let us know how many turns out it takes. One turn is a 360 degree turn by the way.

So have a coffee break  (or stiff drink) away from the bike and start with a fresh mind.
Only try to tune the idle for the fastest, strongest idle and tell us what happened. Don't even ride the bike yet, just idle tuning. Warm the bike up and go for the fastest idle, then if it goes over 1250, set it to 1250 with the idle speed cable and then keep tuning to get it the fastest, strongest idle until it's as good as it gets. Only the idle mixture screw . Hey, leave that air jet screw alone! Try and improve the idle speed until you can't, only using the idle mixture screw, resetting it to 1250 on the idle speed knob if you get it higher. Oi! don't touch the needle! .
Tell us how many turns out and anything that was noteworthy or strange.

About the noise, FCRs twitter even though I don't tweet (too old). A harsh raspy, higher pitched noise and high frequency vibration can mean too lean somewhere and a gluggy, lower frequency, dull vibration can mean too rich. Reading them and where they are in the rev range is the trick without getting confused. But just so you know, FCRs sound like four and twenty blackbirds twittering away under load.

As you can tell, we have done this before and learned the hard way .

[brad black]

every fcr bike i've had has run happily with the idle mixture screw full in.  they idle much richer than i normally set things up, so i had to give up using the gas analyser and going 5% co.

they can also be a little lean on the needle root diameter.  try using an ems or emr needle.

[koko64]

I changed needles in the end. I got hold of both EMR and EMS needles and used the richer of the two. I didn't need to with other bikes that weren't ported which was a relief. My mate did a great job porting the heads which made them very efficient requiring a 50 slow jet (maybe 48) in the end, but with a richer root diameter for the transition to the needle taper.
I know of another guy that needed another needle in the states, it may have been Juniorvarsity.
Hard to know with these W heads, but gotta start somewhere.

[koko64]

every fcr bike i've had has run happily with the idle mixture screw full in. 

Definitely with the 60 slow jets they come with ime, usually too rich. Only dealt with a handful of 900V motors. I want to see what happens when the IMS is adjusted and if the Slow Fuel Jet needs changing without other circuits like the needle or Slow Air jet Screw being involved. Curious too as to the requirements of the W heads.

But one step at a time.

[ChrisK]

Thank you all.

I have a rainy day here so I think it will actually be a good day to tackle this... after work... 

I will try the baseline setting Koko described above, and try to tune the idle to be its most efficient, then go from there. Documenting every change.

This is similar advice to what I found on this tutorial by Patric Burns: http://www.factorypro.com/tech/tech_tuning_procedures/tuning_FCR_Burns,Pat.html

[koko64]

Yep, that's the bible that one. He's a good guy.

[ChrisK]

Yep, that's the bible that one. He's a good guy.

Unfortunately much of that tutorial is written with the assumption that you have access to a Dyno.

The beginning of it confuses me a bit, because he says that tuning will go much faster if you follow his 5 steps which are:

1. Main Jet and Main Air Jet
2. Needle
3. Slow Fuel and Air Jets
4. Fuel Screw
5. Accelerator Pump

But then he goes on to begin his tutorial by addressing synchronizing and the fuel screw first?

[ChrisK]

I forgot to post this a while back, but does this look like a rich plug to you guys?

[Howie]

Yep, rich.  You need to get the main correct first or nothing else will be correct.  Proper wide open throttle full load operation tells you this is correct.  Next comes needle because that is your part throttle operation.  Slow fuel and air have a lot to do with transition from idle to part throttle.   My guess, since I have not read what he wrote is fuel and synch first because how are you going to run it on the dyno if you can't get it to idle?  Then back to idle when you get everything else correct.

Have you done a compression check, valve clearance, checked for vacuum leaks and checked for proper timing yet?  This is a must!