Eddieb's DR build thread.

[marks]

I took the DR out today for a play

Glen and I spent the day in the Mungy's yesterday on the klr and dt - you would have been welcome to join us. We need some way of letting local plp know about 'arranged the night before' type of rides. a txt group or something?

[NordieBoy]

While I was putting the bike back together last night I found a loose plug under the rear end of the tank. It has a red and a black wire. Is it supposed to be loose? anyone know what it's for? I couldn't find a mate for it.

Yep. It's a loose plug.
Mine has a little cap over it.

[Eddieb]

Glen and I spent the day in the Mungy's yesterday on the klr and dt - you would have been welcome to join us. We need some way of letting local plp know about 'arranged the night before' type of rides. a txt group or something?

Yes I'm keen to go up there, yesterday though I had a pillion on board.

Even posting up on here would be a start

[Eddieb]

While I had the seat off last night I also removed the airbox snorkel. It simply pushes into the top of the airbox so no cutting or modification is required, you just grab the snorkel and pull and it comes out. It's a free mod and easily restored to stock in minutes if you don't like it.

The butt dyno indicates the bike is a lot smoother and stronger at low revs now, it's removed a lot of the chugging at low revs which has made morning traffic much nicer to negotiate. For me it's been a much worthwhile mod and I'll be leaving the snorkel out.

For those who may be concerned about losing any fording depth you only loose about 2cm.

I forgot to take any pics so next time the seat is off I'll try and remember to take some.

[gav24]

While I had the seat off last night I also removed the airbox snorkel. It simply pushes into the top of the airbox so no cutting or modification is required, you just grab the snorkel and pull and it comes out. It's a free mod and easily restored to stock in minutes if you don't like it.

The butt dyno indicates the bike is a lot smoother and stronger at low revs now, it's removed a lot of the chugging at low revs which has made morning traffic much nicer to negotiate. For me it's been a much worthwhile mod and I'll be leaving the snorkel out.

For those who may be concerned about losing any fording depth you only loose about 2cm.

I forgot to take any pics so next time the seat is off I'll try and remember to take some.

Yeah that whole fording depth thing is a bit of a myth I reckon, Cut the whole top off the airbox and get even more flow going on. If you are riding through water that is the height of the base of the seat then well done! The bow wave created by riding pushes water away anyway.
If your pushing through then the water will be as high as the muffler opening so you probably wouldnt do it anyway without taking some steps to block off a few other oriffaces. Ooo errr!
My aftermarket foam air filter just about refuses to get dirty anyway - even pretty dust proof! Good design suzuki (yes it is oiled! I double checked that one when it stayed so clean!)

[gav24]

The air cut valve is on the side and is missing from that one.

Thanks Nordie, I'll keep looking for the YFZ ar the KTM one instead then. Good ol' ebay!

Back to Eddies DR - normal service can resume!

[Eddieb]

http://www.kiwibiker.co.nz/forums/sh...post1130010923

$2500 with Acerbis tank, in auckland

[NordieBoy]

$2500 with Acerbis tank, in auckland

Acerbis tank?

Looks like a Clarke with Acerbis steekers.

But it's got the cool purple frame for bonus cool points.

[GSers]

The 39 flows better than the BST 40 as there's no butterfly in the way of the flow.

That cable out the top is the hot start cable.
The air cut valve is on the side and is missing from that one. The accel pump bleed valve is closed on that one too but if you put on an adjustable one then you're meant to block it off anyway. If you run without it, it'll bog heavily on slow throttle openings and at low speed will stall (as the YZF riders will attest). The bleed valve shunts more of the flow back to the float bowl at slower openings.

It'll work but backfire more than one with the air cut valve.

I've got one the same one on the shelf for parts that I may convert one day.

Nordie, you now have me confussed what is the difference between the hot start cable and the air cut valve. From what I have read on forums and in the earlier YZ manual it looks like exactly the same thing but a later version.
From what I can see the earlier model with the red button on the side had a manual decompression lever on the bars. This was done away with on the later models as the decompression was installed in the exhaust cam with a centrifugal mechanisim and the hot start valve / air cut valve was relocated to cable operation on the bars to make clutch and hot start an easier operation. I have read that this is a lean out operation or air bypass to avoid flooding after you fall off.I have not looked inside it at all. But could be tempted.( Fuel injection rules bloody things keep running even if they are upside down.)
GSers

[NordieBoy]

Nordie, you now have me confussed what is the difference between the hot start cable and the air cut valve. From what I have read on forums and in the earlier YZ manual it looks like exactly the same thing but a later version.
From what I can see the earlier model with the red button on the side had a manual decompression lever on the bars. This was done away with on the later models as the decompression was installed in the exhaust cam with a centrifugal mechanisim and the hot start valve / air cut valve was relocated to cable operation on the bars to make clutch and hot start an easier operation. I have read that this is a lean out operation or air bypass to avoid flooding after you fall off.I have not looked inside it at all. But could be tempted.( Fuel injection rules bloody things keep running even if they are upside down.)
GSers

The air cut valve is on the choke side and on that one is a circular indentation with 2 blind holes.
On the "proper" carb theres a diaphram, spring, cover and 2 screws on there too.

[GSers]

The air cut valve is on the choke side and on that one is a circular indentation with 2 blind holes.
On the "proper" carb theres a diaphram, spring, cover and 2 screws on there too.

Nordie, you are correct that diaphragm is missing of the side of it. I wonder if it was not required on the carbs with throttle position feedback because the probably altered the timing to overcome this issue IE retard the timing at low throttle openings which would help with back fire and low down surging
GSers

[Team Buffoon]

Eddie you were after some weren't you.

http://www.trademe.co.nz/Trade-Me-Mo...-360473527.htm

[NordieBoy]

Nordie, you are correct that diaphragm is missing of the side of it. I wonder if it was not required on the carbs with throttle position feedback because the probably altered the timing to overcome this issue IE retard the timing at low throttle openings which would help with back fire and low down surging
GSers

All the FCR's have the throttle position sensor.
In a race situation, no one cares if it backfires on the overrun. Trail riding they do.
YZ's are race bikes after all.

Similar with the missing leak jet. Race bikes are not usually ridden off idle with slow throttle openings.

With the carb size, the 725 and 780 may benefit from a 40 or 41mm pumper but mxrob has tried them on the 644 with high comp piston and 223 webcam, with performance drops.

The 650 port sizes and combustion chamber are very old tech.
Even a mid-80's Yammy 600 had bigger valves.

[Woodman]

Do these carbs actually increase horsepower on a standard engine? or just help with throttle response?
I spose if you are doing a lot of hp mods then the cv would have to be replaced.

Apparently they are a dismal failure on klrs.

[Eddieb]

Do these carbs actually increase horsepower on a standard engine? or just help with throttle response?
I spose if you are doing a lot of hp mods then the cv would have to be replaced.

Apparently they are a dismal failure on klrs.

From what I have read the carb and a pipe can add ~10% to peak HP

Here's some dyno graphs from the Guru, MX-Rob, http://mxrob.com

1) Pipe comparison with stock carb


2) GSXR pipe with FCR carb