I've used a soldering iron to heat bolts that were red loctited. The stuff is pretty tough but far from permenant. I had a loctited bolt work its way loose from an AK trunnion twice before i stuck that thing in there with JB weld.

 

Thanks mate. Yeah, I do agree that the spigots are wrong and that my adapter may not be exactly the same size as yours. I actually did try checking the Sudco catalog to get an idea of what I should be aiming for with dimensions. That's why I think I got the engine side about right, but there is nothing I can do about the airboot side one being oversized other than push the boot on as far as I can.

Nice to know I'm not the only one with the tank touching problem. Similar to you, I have put in a spacer (2 washers totaling 5mm) under the rear tank mount to hold the tank off the carb so there are a few mm clearance now. The seat just fits on now, but it fits! So I have clearance all around - tank, header, and starter.

Noted. I have just check tightened the clamp so hope it will be secure now.

Cool. Once I get the bike running properly on the carb I will try sorting that out.

Thank you! My trials continue...

 

as others have said, when you get it sorted out, it's a pretty cool mod if you ride off road - makes the throttle response so much sharper. Maybe we both ought to just carry the other cable in our packs when we ride out in the sticks, just in case? dunno. I've had my FCR fitted for > 1000kms and it's working pretty well.

 

OK, got to test run the bike this afternoon.

Starting the bike cold (35C/95F ambient temps) was difficult as there is no choke and pumping the accelerator to make the AP inject extra fuel (like a choke would) got the engine close, but wasn't close enough. Push starting the bike was successful though. That leads me to believe I am pretty close with the jetting.

When cold, I can set the idle to a reasonable level (1500rpm-ish). The bike accelerates decently - not too snappy, but it doesn't bog either. That leads me to believe the AP is not pumping too much fuel into the cylinder on initial acceleration. To this end I am debating increasing the amount of pump to help me cold starting and to improve low end response. Is my logic correct, or am I off the mark?

Now, when the bike gets up to a running temp (coolant temp over 65C) the problems begin. The bike runs fine in the mid to high throttle openning, so without checking spark plug colour I believe I cannot be too far off the mark on the main jet and needle clip side of things. However, when I pull the clutch in after going around 4000-5000rpm mark the engine stalls. Even after being at low rpm's and just letting the engine return to idle it stalls.

After reading the Jetting 101 thread on the DBW forums (http://www.dirtbikeworld.net/forum/s...ad.php?t=26074) I am tempted to believe my air fuel mixture is too rich and/or my pilot jet is too big. That would explain the engine running fine when cold, as if I had a choke on. When the engine is warm, I think the over rich mixture is then choking the bike to stalling. Does that sound about right?

I plan to try and turn the a/f mixture screw in (clockwise) 1/4 turn at a time to see if that improves things. If I have to go less than 1 turn in I plan on trying a #50 pilot jet. Only once I have the idle when warm do I plan on playing with the AP length of pump on acceleration.

Do you guys think I am on the right track with my thinking, or do I have it all wrong? Any help would be great, thanks.

 

*sigh* I ended up aborting the FCR this afternoon and putting my stock carb back on. Turns out through my testing I fouled my already 4500km old spark plug to the point it would no longer work. It was only when I put the stock carb back on I realised that though, so I replaced it but didn't have enough time to put the FCR back on and carry on testing. Oh, and I may have run out of fuel without realising it as I was so focused on the carb

In my testing I started with the a/f screw 1.5 turns out. It wouldn't start with estart, even when pumping the throttle to emulate a choke. So I push started it and rode till the engine warmed up (coolant temp around 65C). Rode with the throttle only slightly open to hold revs at just over 2000rpm till she died. And die she did, with a nice big exhaust pop at the end. Isn't that a symptom of it being lean?

Turned the a/f screw out another half turn to 2 turns (in total) - still no estart success so push started. Rode a bit down the road then changed idle to around 2000rpm. Rode back home and let the bike idle till it died. Took about 10-15 seconds at idle till she spluttered out - but no pop this time.

Turned the a/f out to 2.5 turns and the bike idles nice and stable at 1800-2000rpm odd, but as soon as I slow it to around 1500rpm she slowly dies again. But I think the crappy plug was starting to be the cause of poor running. Also, I think I was running on fumes by this stage which obviously makes the bike lean and gave me false "lean" symptoms.

I then went out to 3 turns and the bike basically wouldn't run. that's when I went back to the stock carb and realised my plug was stuffed and I was out of fuel.

So next weekend I will give the FCR another crack and hopefully nail it. I am more confident that I am close now that I know the false lean reads I got with the screw at 2.5 and 3 turns weren't coz of the carb. Hopefully I will have positive reports from that. Of course, it just means I need to then work on testing the main jet and needle position for top and mid range... and then of course there's the AP.

 

Only my thoughts.
By your description above adjusting the idle mixture screw will not help, you are not even in the ball park. Its WAY too rich or lean at idle.

David

 

Thanks David. Fair enough - care to elaborate at all? And advice on which way I go?

 

is the carb new or used?
Have you checked all the jets to be sure they arent varnished over if the carb is used?
while it is out and on the bench check it out.

 

It is a used carb. Before fitting it I took it apart and gave it a good clean with carbie cleaner - so no varnish. Replace the gasket at the top and rubber seal on the float bowl at the same time.

 

Arctra,

You need to establish a solid baseline and start doing incremental changes from there. With all the fouled plugs and bike running out of gas, it's a total crapshoot where your jetting is now and which way you should go.

You had the bike idling already at the beginning, right?
Bring back all settings to the starting point, or better yet to settings that are known to work for someone else on a comparable bike.

Have you found any info here on this board what jetting anyone else might have used for FCR35?

Then once after you are on at a known spot, bike maybe even idling when hot or cold, THEN start incrementally searching for best idle.

Take careful notes of what you're doing and change only one thing at a time. Make sure things like plug, air filter, gas etc. are not interfering with your work.
At first it's best to make pretty big changes to get a clear response which direction you need to go to. For example, turn the pilot screw in/out by 1/2 turn and do a repeat test run. A pattern will emerge.

After you have the idle tuned, then search for right main jet.
The airbox lid makes a huge difference in WOT jetting. When searching for best MJ, I find it easiest to try a given jet three different ways:
- with snorkel in place
- lid in place but no snorkel
- lid out
That will quickly tell you if the MJ is small, perfect or too big.

But during those airbox experiments the mid-range will be hit and miss, ignore that. Just focus on the top end with WOT and get that done.

After the idle and WOT are as good as they get, then fiddle with the needle height and AP to get the on-off-on throttle response and steady cruise optimized.

--
Mikko