Yamaha TRX850 Enthusiasts Forum

was getting on with fitting the FCR's when I noticed that the bottom of the right hand carb is hard up against the oil filler, any one had this problem and if so what is the fix?

Making up the cables and made stupid error of soldering on the nipple before I had put on the adjusters - duh

now waiting on new 6mm nipples from Venhills, luckily the weather has turned really shit and I have mega hangover after gig, loads of booze and drunken dancing, woke up feeling like I had been beaten up. Will now quietly watch an afternoon film - luckily the wife was similarly affected

YES, I did! The supplied collars are wrong, not long enough for purpose.
I don`t know where the mistake has been made but I went to some lengths to try to stop it happening at least through the main UK supplier Allens.
I sourced threaded blanks from Allens, finished them both to length by taking off the minimum of material but matching their overall lengths (obviously) and then matching their internal diameters to the carb mouths and putting the lip on the collars O/D`s to locate in the rubbers.
There is a thread here about it all I`ll see if I can find it again, only had it posted somewhere in the last few weeks too.
Edit:

Here you go:

viewtopic.php?f=5&t=7330&p=78440#p78440

From that thread there are links to others too, all on a similar subject matter.

Just had another look, the mani cuse of fouling in the protruding allen bolt on the accelorator pump, I reckon if I replace that with a comntersunk screw and maybe wind the threaded collars out a bit I may get the clearance I need

DO NOT wind the collars out, they will `chatter` in their threads in use and damage WILL occur over time. The collars must be fully seated in the carb body.

Ok, just been fettling my FCR`s while Dawn watches shite telly in the background and I can confirm the overall length of my threaded alloy collars as 47 mm give or take 0.5 mm.
I`m going to take some piccies in a bit but can also confirm:

The mains as 170`s, and the slow running jets as 200`s.

The pilot screws were at 1 turn out from lightly seated and the slow air screws were 1.5 turns out from lightly seated.

They were very clean internally, I`m not going to use my ultrasonic cleaner this time round they are not unduly dirty, nor showing any signs of oxidisation.
Edit:

Oh and the spacing is definately very close to 98 mm centre to centre.

Ok, check these out:
Now they are the collars / stubs I made, they are 46.5 to 47 mm long and have a FULL threaded section, the O/D has only been turned over enough of it`s length to suit the rubbers and the radiused grove to suit has been machined into them too.
Now for the patriotic shot for you Aussies :
A Union Jack tea towel I`m now using for rag, one of my old Mums R.I.P. I found hundreds of new and unused tea towels after I cleared her flat, most are now destined for clean rag use on the bikes.

I know of one fellow who took a dremel to the oil filler tube, no problem

Yes there IS enough meat in the oil tank filler neck wall to do that but I`ve also found that the longer inlet length actually suits the bike and when the FCR`s first went on the bike made a shade under 89 bhp at the wheel with stock headers!
I do not plan on shortening them any time soon.

That was me that did the dremel trick.

You're right, it is the bolt on the accelerator pump that fouls on the oil filler tube. In my case it was touching without any pressure, but I didn't like the idea of the carbs vibrating against the tube.

The walls of the filler tube are quite thick so you can excavate a reasonable sized divot. Obviously you need to go carefully and keep an eye on the progress. I also ground off the head of the bolt on the accellerator pump a little bit.
The result is about 3mm clearance.

I didn't want to use longer spigots as that would affect the fitting of the airbox (although I will eventually have a different air filter arrangement).

Here's my divot, it's not visible unless you go looking for it

my mounting will be a bit different.
Having 4 carbs to choose from helped!
I am running short 11mm extensions from the carbs -see pic

then- The accelerator pump will run on the left hand cylinder (no fouling of oil filler)
I will use shorter bolts on the accelerator pump bowl for extra clearance, there is only a mm or so with the standard bolts.
I have to block off a couple of the accelerator fuel supply lines though.

cheers

Thanks Guys, will try replacing allen bolt with counter sunk screw and maybe relieving the filler neck a tad if I have to. As I no longer have access to a lathe, machining up newcollars will be a real pain in the a**e - though maybe Kayla could give me a price? I hope the F'ing FCR's are worth the bother!

You`ll never go back to Micky Mouse asthmatic CV`s again I can assure you!

what ^^^^ said


Mince mate was that T towel flown at see?? If it was you are correct if it wasnt then it is a Union Flag sorry to be pedantic lol.

Do you know Kenny it`s never even been unfolded since it was bought! My old Mum hoarded tea towels and never used them, I hoard all kinds of useful `stuff` myself hence a flat that`s like a bike breakers with dust.

SDN wrote:Thanks Guys, will try replacing allen bolt with counter sunk screw and maybe relieving the filler neck a tad if I have to. As I no longer have access to a lathe, machining up newcollars will be a real pain in the a**e - though maybe Kayla could give me a price? I hope the F'ing FCR's are worth the bother!

Don`t go bothering Kayla for those she couldn`t easily do them (screwcutting required) plus she`s VERY busy just now.
Allens will supply machined and threaded blanks, you simply turn them down or even hacksaw them down to the length you require and finish them with a file to keep them square dimensionally end to end.
You will require to turn the O/D to fit the rubbers and add the wee radiused groove too by the way.

Mincehead wrote:

SDN wrote:Thanks Guys, will try replacing allen bolt with counter sunk screw and maybe relieving the filler neck a tad if I have to. As I no longer have access to a lathe, machining up newcollars will be a real pain in the a**e - though maybe Kayla could give me a price? I hope the F'ing FCR's are worth the bother!

Don`t go bothering Kayla for those she couldn`t easily do them (screwcutting required) plus she`s VERY busy just now.
Allens will supply machined and threaded blanks, you simply turn them down or even hacksaw them down to the length you require and finish them with a file to keep them square dimensionally end to end.
You will require to turn the O/D to fit the rubbers and add the wee radiused groove too by the way.

Ahem! Just how do you know what I can and can't do? Just because I'm busy and we have stuff everywhere doesn't mean I can't do some work (or get it done). I'll say 'yes' or 'no' I can't do something if that's ok.

SDN- Send me a sketch and I can ask my man with a CNC lathe to do them