Suzuki GT750 Neuvo Retro Cafe Racer

[tz375]

And I know how that will end

[tz375]

Just a quick FYI.
I opened the garage doors today just before the snow started for real and fired up the Phat Trakka. After it warmed up I was seeing an A:F of 14.7-14.8 at idle. When I blipped the throttle the ratio bounced from 12.5 at 6k to around 17-18:1 in between. That was just blipping the throttle and not under load so it doesn't tell us mush about anything but it was eye opening.

That was on an Innovate MX-L digital meter with Bosch LS-2 ultrawideband 5 wire sensor. Now I really need to add on the TPS and an Aux-Box to collect data on TPS RPM and Lambda to see what this beat is doing.

[CJF]

Have you seen any issues with the sensor going bad due to the 2 stroke oil/exhaust? I read a few things about the eg sensors having issues on a 2 stroke. I thought about trying one on my bike, but ended up going with a CHT gauge instead.

[tz375]

You are correct that they don't do as well in an oily atmosphere. Mine is in there for testing and jetting and after that it comes out.

[Rassie]

Just a quick FYI.
I opened the garage doors today just before the snow started for real and fired up the Phat Trakka. After it warmed up I was seeing an A:F of 14.7-14.8 at idle. When I blipped the throttle the ratio bounced from 12.5 at 6k to around 17-18:1 in between. That was just blipping the throttle and not under load so it doesn't tell us mush about anything but it was eye opening.

That was on an Innovate MX-L digital meter with Bosch LS-2 ultrawideband 5 wire sensor. Now I really need to add on the TPS and an Aux-Box to collect data on TPS RPM and Lambda to see what this beat is doing.

That is interesting indeed. So it went from (rounded numbers) 15 to 17-18 and then 12.5 at 6k rpm. I am sure there is an indication in there. It would lead me to think larger main jets and no lean condition on part throttle. That is if the base is correct. Would be totally off if the start is say supposed to be around 18 and then run to 20 or so at 6k rpm. Speculative I know but it does make you want to do something with those numbers.

[tz375]

It should theoretically be 14.7:1 but needs to be richer when accelerating at say 11-12:1. 15 is fine in an EFI car in cruise mode.

I have the rest of the Innovate data logging gear on order and when it gets warmer, I'll see what happens on the street. I also designed a TPS arrangement on the oil pump so I can plot A:F against RPM and throttle position and it comes with MAP which might be interesting.

we need the snow to go though. I can't ride with salt and slush on the roads.

[Rassie]

It should theoretically be 14.7:1 but needs to be richer when accelerating at say 11-12:1. 15 is fine in an EFI car in cruise mode.

Gotcha so there is still the indication of a lean mixture mid throttle/rpm then. I hope your weather gets better soon...so we can get some facts

[Rassie]

No further development here, but got some publicity today..
http://silodrome.com/suzuki-gt750/" onclick="window.open(this.href);return false;

[Rassie]

Finally got around to doing the "surge mod" and install the larger size 122.5 jets. Ringding was at my place on Saturday working on his RD400 project, so he motivated me to get the Threesome sorted. I did the airjet mod with the .80 jets. So here is the setup now.

Main 122.5
Pilot 47.5
Airjet mode with .80
Needles on the lowest clip and one small washer underneath which is about half a clip width. I expect it will run the same without the washers, since I could not detect any difference after I installed them.

The result is just what I was looking for. I took her out for a spin this afternoon and there is absolutely no surging whatsoever now. She also revs out much better and my seat of the pants says she is running a little faster. In conclusion then if you are running open filters and some Jemco pipes then this is the setup you need to run or at least start off with when tuning. I should be able to get a longer ride in next weekend and will report back on how it runs on the highway and at wide open throttle. Based on the short run I did today I expect it to run perfectly.

[cruisingram]

Hey- beautiful build. What fairing and tail piece are those?

I see you used the rickman and the Ducati SS stuff- but did you order them new or get them off e-bay or something?

[Rassie]

Rickman tail and Center fairing section is from Airtech. The sides of the fairing are OEM sections that I trimmed to fit.

[Suzukidave]

You know you are big time when your bike is displayed in a Google search https://www.google.com/search?q=suzuki+ ... 20&bih=993" onclick="window.open(this.href);return false;

[Rassie]

Believe what you see on the internet

[cruisingram]

Rickman tail and Center fairing section is from Airtech. The sides of the fairing are OEM sections that I trimmed to fit.

You have any shots of how you did that front fairing mod?

[Rassie]

Here you go. Basically i took to plastic tops from a container that was about the same size as the lights and mounted them on a flat plate with the correct spacing using a nut and bolt in the center so they can rotate. I made a hole on the one side so I can slide a sharpy or other marking pen through the hole. Then I traced the hole by rotating the disc. Use dots and not a line, if you try drawing a line it will go out of round, just place dots about 1mm apart as you slowly rotate the disc. Then cut on the inside so it is a bit smaller and use sandpaper attached to a pipe of similar but smaller diameter to sand the hole to an exact fit.