GS1100E modif and Mikuni

[Guest]

Hello

I`m going back to carb solution on my light modded GS1100E, from some years with aftermarked injection .
Has anyone a GOOD experience for first choice of jets and repair kit to my original Mikuni carburator with the following engine upgrade:

4 pcs sportfilters +
WGS348(168) (70-112)
.348"
257° Dur @ .050
Hot street & strip big bore motors. Strong mid range and top end. APE valve springs required.


Engine comp: 10.2 : 1

I just looking for a kit to start with. ( I know there has to testet before it got OK )

Regards
Knut

[posplayr]

I assume pods and 4:1, 36mm bs36? I would figure 140-142 mains with dynojet needles and the 47.5 pilots.
With 4:2:1 my experience has been you can lower the main and pilot from that and gain mid range. With 340 webcams but fairly aggressive porting I have 135 mains and 45 pilots all jetted at sea level with an innovate SB o2 sensors and a big long hill.


I was wondering if you could describe you fuel injection system and why you are going back to carbs?

[gsx1100norway]

Thanks a lot Posplayr for your advice and info.

Regarding converting back to carbs....
The main reason is that my trottlebodies and injectors start to be worn together with my experience of this Megasquirt system ain`t that good.
I have also had some rides with electronic failures that ended up on a truck back home... ( Broken temp sensor and blown fuse.... )

Costs and experience tell me that : Happy driving = Good shape carbs !

KnutK

[posplayr]

Thanks a lot Posplayr for your advice and info.

Regarding converting back to carbs....
The main reason is that my trottlebodies and injectors start to be worn together with my experience of this Megasquirt system ain`t that good.
I have also had some rides with electronic failures that ended up on a truck back home... ( Broken temp sensor and blown fuse.... )

Costs and experience tell me that : Happy driving = Good shape carbs !

KnutK

I am actually contemplating designing an EFI system. I guess you could characterize it as being similar to a Mega squirt but more specific to motorcycles (i.e. smaller), more robust and easier to integrate. It would be an extension of (integrated with) the electronic ignition I'm working on. Obviously the ignition would need to be sorted first and the EI is really more of an add on to the EFI.

My question is from a drive ability and horsepower standpoint, what improvements can be obtained from a basically stock 16V GS by adding EFI? Do you have any O2 data or other performance data or just subjective thoughts would be nice as well.

If it was not for the reliability issues, would you stay with EFI v.s a Carb setup?

[ArttuH]

My question is from a drive ability and horsepower standpoint, what improvements can be obtained from a basically stock 16V GS by adding EFI? Do you have any O2 data or other performance data or just subjective thoughts would be nice as well.

Here are a couple of old dyno graphs from my GS1100.

Carbs, stock engine except K&N filter in the stock air box and aftermarket 4-1 exhaust (quiet): http://www.amh-sivut.net/mopo/dyno_ennen.jpg

EFI, pod filters and more free flowing exhaust: http://www.amh-sivut.net/mopo/dyno_nyt.jpg

Please note there are just few actual measurement points on both graphs so curve shapes are slightly weird. But they show well difference in top end power and midrange torque.

Subjective change was also quite significant. EFI pulled much more smoothly and strongly at all revs and especially at low/mid range.

I have been quite happy with reliability too. But I have been using my own ECU designs (Megasquirt based) and reliability in bike use has been one important design criteria.