BDT 38mm carbs on a GS 1150

[posplayr]

Thats interesting.
I always found it difficult to do proper main tuning on the street because I would have to find a place with a long enough straight, no people. And I was told years ago to try to find a slight uphill grade, if you can, but it all had to be long enough to stay near or at redline for 10 or more seconds to really get a the proper main jet. Just trying to hold it near redline in 4 or 5th for 10 sec is hard enough and frankly a bit dangerous on the street. Dyno tuning is the way to go but I think you need the right operator some of the kids I have seen on the dyno's here scare me worse than WOT on the street

Anyway my last go around with the 38mm cv's I ended up with 150 mains but it was weird it would stumble at 8500rpm then it would pull really hard. 145 mains the stumble wouldn't be there but it would not pull as hard or reach the speed at the same point on the run as the 150's. It also now wants the needle all the way down to the leanest setting. It made me want to try the power jet system that is on the 38's that is blocked off at the factory. I talked to Marc the owner of Factroy Pro and he said it wouldn't work anyway and I think he may know a bit more than me! Marc suggested trying a slightly larger air jet to compensate for the stumble. I may try it.

Right now Im sticking with the 145 mains, the needle is still all the way down. This winter I will rebuild, nickel plate the tubes, and have at it again next year.
I am actually hoping the nickel plating will restrict the needle jets to lean it out a bit on the needle, but the research I have done on it suggests I would need 4 or 5 mils of plating which from what I have read is a lot. And theres are small holes in the needle jet and that much plating inside those might be to much. I am willing to wreck a set of tubes for the experiment so we will see what happens when I do it!

I think no matter how you do it, trying to measure WB02 at past redline needs a data logger. However, holding a 1100 past redline but in steady state is a challenge.

[posplayr]

Posplayr I am a big fan of Innovate products. I have a LM2 which I used to DL on my 08 Corvette when I was chasing a moderate throttle surge problem. I have a 03 HD Dyna superglide with a S&S 124 C.I. motor that I use a Innovate digital air fuel gauge on to tune with (no data logging) and use Dynojet's auto tune modules on my Yamaha & Honda to fine tune the FI. High tech products like Innovate make the tuning process much faster and more precise.

I assume you are using the LM-2 with OBD-II? If you have fuel injection and OBD-II then the OT-2 is all you really need unless you are trying to get individual port AFR measurements and need the LM-2 WB. Obviously for CV carbs on a GS there is no OBD-II and although the LM-2 and LMA-3 do pretty much most of what they say, there were chronic issues with timing signal. I'm not sure if they ever fixed them since 2010 when I think I was doing this. There were circuit problems in the I/F modules on teh LMA-3 and the LM-2's RPM did not seem to want to work anyway you used it. Even after I got everything working, it was pretty disillusioning to have Innovate shut down the Support Forum. So I really can't claim to be a fan, nor even recommend the products. Without the website, forum who knows?

10 years ago I bought a Unitek A-100 elapsed timer to use on my Harley. This is a digital programmable timer that measures the ET between two programmable RPM settings with a resolution of .01 seconds. The timer is really useful in setting the main jet size based on real world conditions. When used in conjunction with the Innovate Digital A/F gauge I found the 124 C.I S&S motor produced the fastest ET's at 12.8/1 AF ratio. I haven't been able to use the A-100 timer on any other bike I have owned because all of them had stick coils except the Harley. The A-100 timer uses an inductive pickup that clips on a spark plug wire. It will work on the GS 1150.

With a data logger you should be able to derive similar information just counting integrated RPM's (or speed) over a period of time. The RPM is time tagged and so if you compute average cycles per sec for say 10sec as the integrated RPM over a selected period it is basically the same thing done without any timer. You do need clean timing signal though.

This is a plot of showing comparison of SPEED and RPM from the LMA-3
RPM_ACCURACY.jpg

[jstewart]

I am not going to use this system (LM-2) on the GS 1150. I only used it on the 08 Corvette. I am going to stick with the old fashioned way for setting jetting on the 1150 plus the A-100 timer to get the main jets close. If this proves insufficient to identify problems I will use the local Ducati/MV Agusta/Suzuki shop's Dynojet 250I load control dyno. This shop has a service manager who is very experienced and talented at dyno tuning motorcycles both carbureted and fuel injected.

I assume you are using the LM-2 with OBD-II? If you have fuel injection and OBD-II then the OT-2 is all you really need unless you are trying to get individual port AFR measurements and need the LM-2 WB. Obviously for CV carbs on a GS there is no OBD-II and although the LM-2 and LMA-3 do pretty much most of what they say, there were chronic issues with timing signal. I'm not sure if they ever fixed them since 2010 when I think I was doing this. There were circuit problems in the I/F modules on teh LMA-3 and the LM-2's RPM did not seem to want to work anyway you used it. Even after I got everything working, it was pretty disillusioning to have Innovate shut down the Support Forum. So I really can't claim to be a fan, nor even recommend the products. Without the website, forum who knows?



With a data logger you should be able to derive similar information just counting integrated RPM's (or speed) over a period of time. The RPM is time tagged and so if you compute average cycles per sec for say 10sec as the integrated RPM over a selected period it is basically the same thing done without any timer. You do need clean timing signal though.

This is a plot of showing comparison of SPEED and RPM from the LMA-3
[ATTACH=CONFIG]41688[/ATTACH]

[Joe H]

I am not going to use this system (LM-2) on the GS 1150. I only used it on the 08 Corvette. I am going to stick with the old fashioned way for setting jetting on the 1150 plus the A-100 timer to get the main jets close. If this proves insufficient to identify problems I will use the local Ducati/MV Agusta/Suzuki shop's Dynojet 250I load control dyno. This shop has a service manager who is very experienced and talented at dyno tuning motorcycles both carbureted and fuel injected.

Any progress with jetting, how about the 38's?

Just wondering

[Joe H]

Here are some pics of the needle jets from the 38mm cv's
Notice the wear inside the tube, you can only see it under magnification, looking at it with my old eyes I couldn't see it. These Needle jets have at least 15,000 unfortunately I don't have a exact milage count on them

The ones I have in the carbs now have about half that much wear in 2000 miles.


.




The wear is at the top of the picture inside the tube

[jstewart]

Thanks for the pictures Joe. Now I know for sure the emulsion tubes in my carbs are stock and not dynojet. They have exactly the same stamped numbers as the one in the pictures. This set of BST 38mm carbs has a mishmash of stock & dynojet parts. The needles, mainjets & pilot jets are dynojet while the emulsion tubes are stock. The slides have the dynojet restrictor installed in one slide lift hole. According to dynojet the dynojet emulsion tubes should have been installed for both a stage 1 & stage 3 kit. I should have the bike finished tomorrow using the stock carbs, airbox and exhaust system. I am running a K&N filter in the stock airbox without the top of the airbox installed. Curious to see how the bike performs with the 1229 kit, Web 340 cams, ported head, dyna ignition & 2 ohm coils and the stock exhaust system. After I break in the new rings and run enough miles to get this setup right (jetting & ignition settings) I will move on to the V&H header and larger carbs. Hopefully I can dyno test each setup for comparison.

John

Here are some pics of the needle jets from the 38mm cv's
Notice the wear inside the tube, you can only see it under magnification, looking at it with my old eyes I couldn't see it. These Needle jets have at least 15,000 unfortunately I don't have a exact milage count on them

The ones I have in the carbs now have about half that much wear in 2000 miles.


.




The wear is at the top of the picture inside the tube

[Joe H]

I hope you get to test each setup also it will be an interesting comparison. When I bought my 38's they came with Dyno-jet needles and stock needle jets also. This discussion we have been having has made me go back and look at all my old carb parts….just WOW …way to many! And on top of that I am now collecting a lot of mikuni VM jets for my H2 project!

I may try the euro needles for the 38mm cv carbs, they are adjustable and they have two different sizes available I just need to find out which one is leaner and which is richer, I am hoping I can find the specs on them for taper to compare them to what I have already.

[jstewart]

Joe I seem to take two steps forward and then one step back. I had the bike running (stock dynojet kitted carbs, stock airbox with K&N filter & stock pipes). Everything seemed fine and I went for a short test ride and got 2 miles and the bike sputtered and died. It would crank but not re-start. Called the wife to bring the truck & bike trailer and hauled it home. Found the stator had one open winding and was not charging. The Dyna 2000 ignition shut down when the battery voltage dropped even though the battery was still charged enough to spin the motor. Ordered a Rick's motorsport stator today which will be here next Tuesday. This restoration project has been like peeling an onion. The bike was in beautiful cosmetic condition except for some rust pits on the stock center pipes (#2 & #3). All the motor work was my choice as there was nothing wrong with any of the stock internals when I tore it down. Electrics were another matter. The module that checks everything from low battery acid level, head & taillight bulbs, side stand position, ect was bad. The self cancelling turn signal relay module was bad. One ignition coil was intermittent and more than a dozen wiring connectors and the fuse box had corrosion that had to be cleaned. Both of these components are listed as no longer available but my dealer found both in two separate Suzuki parts warehouses. I am going ahead and replacing the stock voltage regulator with a Compufire unit next week when the new Rick's stator arrives as a precaution. I think these two items are the last of the problems keeping me from moving on to enjoying this bike and further experimenting with carburation and pipes.


John

[posplayr]

If you were not aware, there is a link that will solve many if not all of your charging problems.

http://www.thegsresources.com/_forum/showthread.php?152769-GS-Charging-System-Health&p=1138531#post1138531

I'm not sure how low the Dyna 2000 shuts down but I can't believe it is at 12.8V as if it would not run on battery [power the bike would never start. That leads me to think you have power distribution issues; do you have a Ignition Relay Mod installed?

[Joe H]

I kinda agree with posplayr, I have had my bike fire up with nearly no battery both with the starter and by bump start and I am running the Dyna 2000.

I have had MANY electrical problems over the years, most of the time it was bad/dirty connections. I have replaced the R/R 3 times finally went with the Compufire this summer. I also think my stator is a bit weak, unfortunately Im not bright enough to follow most of the electric stuff so I am left replacing things when they fail and leave me stranded!
That black box I have replaced once. I did have to have Dynatek replace the Dyna 2000 I bought when they first came out, I was getting bad detonation and I couldn't figure it out so I sent the Dyna 2000 in to have it tested and they sent me a new unit free… but that was when they first came out. I have had NO problems with this one for many years and would recommend them enthusiastically from my experience with it.

Its so freakin' frustrating, problems like that have kept me up at night! It drives my wife crazy

Im sure the new parts will get you going (hows your starter clutch, your in the neighbor hood now).

And get this… my self canceling turn signals NEVER worked…until this summer after I put in the Comupfire…. I know this is a fluke and has nothing to do with it but I found it comical !!!!! Must have bumped something!!

I have a plan to someday go thru the entire thing and re-do, clean up and check all the wiring…. someday after I get stranded…LOL

[jstewart]

I feel really stupid but I know why the bike would crank over but was not firing the plugs after a short ride. The Dyna 2000 plug was not fully seated. I noticed several times before the bike quit running that the tach would drop out and then start working again and It was right after I turned around to take the bike back to the garage to investigate that it quit running. The stator was bad and I replaced it with a Rick's and replaced the RR at the same time with a Compu-fire #55402. This winter I plan on replacing the fuse box with Posplayr's solid state box if he is still offering them for sale. Everything is now functioning and I am taking short rides (30 to 40 miles) to break in the rebuilt motor.

If you were not aware, there is a link that will solve many if not all of your charging problems.

http://www.thegsresources.com/_forum/showthread.php?152769-GS-Charging-System-Health&p=1138531#post1138531

I'm not sure how low the Dyna 2000 shuts down but I can't believe it is at 12.8V as if it would not run on battery [power the bike would never start. That leads me to think you have power distribution issues; do you have a Ignition Relay Mod installed?