Carb tuning after fitting a Wiseco 1085 kit?

[John Kat]

Would fitting a Wiseco 1085 kit to a GS 1000 ET require any change to the carb settings?
I had spent many hours tuning the carbs before the conversion and now I feel like I'll have to restart from scratch.
Above 1/4 throttle the bike hesitates while accelerating and the exhaust pops on the overrun???
I checked for air leaks from the exhaust gaskets and double checked the valve clearances as they are new.
Any ideas?

 

[posplayr]

Would fitting a Wiseco 1085 kit to a GS 1000 ET require any change to the carb settings?
I had spent many hours tuning the carbs before the conversion and now I feel like I'll have to restart from scratch.
Above 1/4 throttle the bike hesitates while accelerating and the exhaust pops on the overrun???
I checked for air leaks from the exhaust gaskets and double checked the valve clearances as they are new.
Any ideas?

Yes it will change. Considering your interest in the sport, I would invest in a O-2 sensor with data logging. It is really the only way to go. Of course you do need to be able to get a constant load from a long hill to make good use of the instrumentation. Too fast of acceleration does not really let the conditions settle enough to really see what is going on.

I would guess the main will go up 2-4 steps, which will throw everything else below off.

 

[ozman]

Would fitting a Wiseco 1085 kit to a GS 1000 ET require any change to the carb settings?
I had spent many hours tuning the carbs before the conversion and now I feel like I'll have to restart from scratch.
Above 1/4 throttle the bike hesitates while accelerating and the exhaust pops on the overrun???
I checked for air leaks from the exhaust gaskets and double checked the valve clearances as they are new.
Any ideas?

more cc usually means jetting up, the popping on overrun can be a indication of running lean
do a plug chop and check it out

ozman

 

[John Kat]

I followed the advice and upped my main jet from 137.5 to 147.5 ( Mikuni sizes).
The bike will now take full throttle but still hesitates at mid throttle.
It's my fault as I had lowered the needle 2 slots...
I plan to participate in the next Olympics in the category "Needle and Jet changes" on CV carbs!

 

[posplayr]

I followed the advice and upped my main jet from 137.5 to 147.5 ( Mikuni sizes).
The bike will now take full throttle but still hesitates at mid throttle.
It's my fault as I had lowered the needle 2 slots...
I plan to participate in the next Olympics in the category "Needle and Jet changes" on CV carbs!

The main is the first step, so after that change none of your previous settings are relevant. Generally on a main change set everything else to the middle (needle, pilot if there is a mid size and idle doesn't matter till the end)so you have split the difference already in your binary search.

AFR is a pretty dynamic quantity which is why the RECO for the data logging AFR meter.

 

[John Kat]

AFR is a pretty dynamic quantity which is why the RECO for the data logging AFR meter.

What's your recommendation?
The Innovate product line looks interesting?
I cringe a little to have to solder a bung on my chromium plated exhaust....

 

[posplayr]

What's your recommendation?
The Innovate product line looks interesting?
I cringe a little to have to solder a bung on my chromium plated exhaust....

I struggled with the Innovate LM-2, and that is when there was a forum and some form of experts on that website. It seems long gone. You can get an extension (3ft or so) sniffer and run it up to the collector and get good readings.

The bare minimum you need is AFR and RPM and ideally it is recorded. You might be able to use a small spy camera and not have to deal with the whole data logger hassle (and that is my business). No cute graphs but you probably don't need them. However, I did find my clutch slipping just before redline and I would not have been able to do that without the data logger (comparing speed and RPM) under full throttle.

My Innovate system worked well after I got it all sorted, (but I'm an EE ). Part of the solution to get speed and RPM to run together was to open up the boxes, read the data sheets for the parts and design external circuits to overcome the internal design defects. It has been a while yet but I have a pile of stuff still. LM-2 and LMA-3

AFR
RPM
Wheel SPEED
EGT
MAP
G's
http://www.thegsresources.com/_forum/showthread.php?164565-AFR-Info&highlight=Innovate

http://www.thegsresources.com/_foru...LM-2-Firmware-Upgrade-1-14&highlight=Innovate

http://www.thegsresources.com/_foru...itoring-for-CV-CARB-Tuning&highlight=Innovate

There are other options.

http://www.ebay.com/itm/Zeitronix-Z...tem-/261706261324?hash=item3ceee8a34c&vxp=mtr

This is not to dissuade your anything but the Innovate stuff. They seem to purposely construct their products so that you have to but one of these to get that and oh, so you want that also well you need one of these........

 

[John Kat]

The most interesting part you mentionned in one of your threads is this:

• 1 notch rise in needle ( e.g. 4 to 3 from bot)at 1/2 throttle will lower AFR 1 full point (e.g. 14.0 to 13.0).
• A drop in Main by 2 sizes (e.g. 140 to 135) at 1/2 throttle will raise AFR 1 full point.(e.g. 13.5 to 14.5)
• A drop in Main by 2 sizes (e.g. 140 to 135) at WOT ------- will raise AFR 1/2 a point.(e.g. 11.0 to 11.5)

SUMMARY: @ 1/2 Throttle: 1 needle notch = 2 jet sizes


The good news is that by restoring my needle to the 2nd slot from the bottom with the 147.5 main jets the bike goes like a charm.
Of course as I'm still running the engine in, I haven't really tried WOT at high rpm but it looks very promissing.
Stangely, the exhaust still pops sometimes on the overrun???

 

[posplayr]

The most interesting part you mentionned in one of your threads is this:

• 1 notch rise in needle ( e.g. 4 to 3 from bot)at 1/2 throttle will lower AFR 1 full point (e.g. 14.0 to 13.0).
• A drop in Main by 2 sizes (e.g. 140 to 135) at 1/2 throttle will raise AFR 1 full point.(e.g. 13.5 to 14.5)
• A drop in Main by 2 sizes (e.g. 140 to 135) at WOT ------- will raise AFR 1/2 a point.(e.g. 11.0 to 11.5)

SUMMARY: @ 1/2 Throttle: 1 needle notch = 2 jet sizes


The good news is that by restoring my needle to the 2nd slot from the bottom with the 147.5 main jets the bike goes like a charm.
Of course as I'm still running the engine in, I haven't really tried WOT at high rpm but it looks very promissing.
Stangely, the exhaust still pops sometimes on the overrun???

If you think about it, those properties are what force you to pick the main first and then the needle. The needle doesn't effect the WOT AFR, but both needle and main do affect 1/2 throttle AFR.

So until you pick your main, the rest doesnt matter.