Announcement

Collapse
No announcement yet.

Mounting EFI throttle bodies directly to the engine.

Collapse
X
Collapse
 
  • Page of 2
  • Filter
  • Time
  • Show
Clear All
new posts
Previous 1 2 template Next
  • #1

    Mounting EFI throttle bodies directly to the engine.

    I'm currently working on two different project one is a 1982 xj650 maxim/turbo and the other a 1978 XS1100. Both bikes are getting fuel injected using Microsquirt. I would like to make my own throttle bodies and mount them directly to the engine without using rubber boots. The reason for this is to save space and also be able orient the fuel injectors so they squirt more directly toward the base of the intake valves. Also I could easily machine the faces of them to accept Viton o-rings and almost eliminate the chance of vacuum leaks.
    My main question is has anyone here ever tried mounting carbs or EFI throttle bodies without using the rubber boots and if so did it pose any problems?
    80 MNS; 80 F; 82 Maxim 650
    Tags: efi, vacuum leaks
  • #2
    I only know of one person who fuel injected an XS with a Megasquirt and I don't think it was a huge success.

    I applaud the effort and watch expectantly, but after just running 2700 hard, fast miles with regular carbs at a constant 33 mpg its hard to improve on that.

    John
    John is in an anonymous city with an Alamo (N29.519227,W-98.678980)

    Go ahead, click on the bikes - you know you want to...the electrons are ready.
    '81 XS1100H - "Enterprise"
    Bob Jones Custom Navy bike: Tkat brace, EBC floating rotors & SS lines, ROX pivot risers, Geezer rectifier, new 3H3 engine

    "Not all treasure is silver and gold"

    Comment

    • #3
      I have full confidence that the EFI system Itself will work fine, and I am no stranger to converting and tuning engines to EFI.
      The main question is about mounting by bolting directly to the heads vs using the standard rubber boots.
      I have researched the hell out of this subject and cannot find a reasonable answer to why rubber compression boots are used vs mounting directly to the head. The only problems I would expect would be from thermal expansion and thermal conduction to the fuel in the float bowl if carbureted.
      80 MNS; 80 F; 82 Maxim 650

      Comment

      • #4
        Yes. Those carburetors would get very hot mounted directly to the cylinder head.
        Marty (in Mississippi)
        XS1100SG
        XS650SK
        XS650SH
        XS650G
        XS6502F
        XS650E

        Comment

        • #5
          A fella I bought a parts-bike from near Jackson ran a fuel-injected XS1100 with a Megasquirt, with great success. I had the throttle bodies in my garage.
          1979 XS1100F
          2H9 Mod, Truck-Lite LED Headlight, TECHNA-FIT S/S Brake Lines, Rear Air Shocks, TKAT Fork Brace, Dyna DC-I Coils, TC Fuse Block, Barnett HD Clutch Springs, Superbike Handlebars, V-Star 650 ACCT, NGK Irridium Plugs, OEM Exhaust. CNC-Cut 2nd Gear Dogs; Ported/Milled Head; Modded Airbox: 8x8 Wix Panel Filter; #137.5 Main Jet, Viper Yellow Paint, Michelin Pilot Activ F/R, Interstate AGM Battery, 14MM MC, Maier Fairing, Cree LED Fog Lights.

          Comment

          • #6
            I`ve EFI`ed two bikes; a 1980 XS1100 and an 82 XJ1100 using Megasquirt. I've got over 40k miles on them in 9 years and they still run great. Even with alcohol fuel. I let one sit in the garage for over a year and it started right up. In my mind, EFI`ing these bikes was the best mod I ever made. The other mod was swapping out the differentials. I will never use carbs again; too much maintenance.

            I posted my work on the XS11 forum under fuel modifications, but the web host I was using closed down earlier this year. I'll rework the write-up and make it into an attachment.
            '80 XS1100LG Midnight Special
            Looks like an '82 Maxim, Fuel Injected
            '82 XJ1100J, Fuel Injected
            Stan Hutchison

            Comment

            • #7
              It was a great write-up Stan. I looked into your webpage a few times, and ultimately found it outside my skill-set. I do believe there were a few other members on here who did a Megasquirt EFI setup, and it was found through their comments on the build that the mpg's were not significantly different between an EFI bike, versus a factory carb setup.
              1979 XS1100F
              2H9 Mod, Truck-Lite LED Headlight, TECHNA-FIT S/S Brake Lines, Rear Air Shocks, TKAT Fork Brace, Dyna DC-I Coils, TC Fuse Block, Barnett HD Clutch Springs, Superbike Handlebars, V-Star 650 ACCT, NGK Irridium Plugs, OEM Exhaust. CNC-Cut 2nd Gear Dogs; Ported/Milled Head; Modded Airbox: 8x8 Wix Panel Filter; #137.5 Main Jet, Viper Yellow Paint, Michelin Pilot Activ F/R, Interstate AGM Battery, 14MM MC, Maier Fairing, Cree LED Fog Lights.

              Comment

              • #8
                I've got to agree with the other EFI reports, my gas mileage has never been as good as my original website ride report. I believe I know why. I was using premium 93 octane pre-alcohol fuel with an advance timing curve and some lean setting. Also, my XS has never gotten as good of mpg as the XJ. The XS has a full windjammer fairing and hardbags. I've got over 10k miles on the EFI XS using 86 octane and alcohol fuel and get a consistent 34.5 mpg. The XJ gets 38 mpg. We government's fuel policy was a mistake.
                '80 XS1100LG Midnight Special
                Looks like an '82 Maxim, Fuel Injected
                '82 XJ1100J, Fuel Injected
                Stan Hutchison

                Comment

                • #9
                  After dwelling on this subject longer. I think what I'm going to do is machine 1/4" thick spacers out of Teflon sheet and sandwich it between the head and the throttle bodies. The Teflon is stable up to 450 degrees so it shouldn't break down and this should insulate the throttle bodies and injectors from excessive heat.
                  80 MNS; 80 F; 82 Maxim 650

                  Comment

                  • #10
                    Interesting solution.
                    1979 XS1100F
                    2H9 Mod, Truck-Lite LED Headlight, TECHNA-FIT S/S Brake Lines, Rear Air Shocks, TKAT Fork Brace, Dyna DC-I Coils, TC Fuse Block, Barnett HD Clutch Springs, Superbike Handlebars, V-Star 650 ACCT, NGK Irridium Plugs, OEM Exhaust. CNC-Cut 2nd Gear Dogs; Ported/Milled Head; Modded Airbox: 8x8 Wix Panel Filter; #137.5 Main Jet, Viper Yellow Paint, Michelin Pilot Activ F/R, Interstate AGM Battery, 14MM MC, Maier Fairing, Cree LED Fog Lights.

                    Comment

                    • #11
                      I would be

                      very interested in seeing that write up when you do it again.

                      Not sure if the front end investment is justifiable but if getting rid of carb fiddling is the end result that's something I would go for as that seems to be a major time sink on these bikes.
                      79 SF & 80 LG MNS
                      73 & 74 RD 350's
                      73 Honda CL 450
                      Graveyard - '81 XS850 Special

                      All of my bikes are projects, maybe one day I'll have them running.

                      Comment

                      • #12
                        Originally posted by Joe Bartelt View Post
                        After dwelling on this subject longer. I think what I'm going to do is machine 1/4" thick spacers out of Teflon sheet and sandwich it between the head and the throttle bodies. The Teflon is stable up to 450 degrees so it shouldn't break down and this should insulate the throttle bodies and injectors from excessive heat.
                        considered carbon-fiber?.
                        81H Venturer1100 "The Bentley" (on steroids) 97 Yamaha YZ250(age reducer) 92 Honda ST1100 "Twisty"(touring rocket) Age is relative to the number of seconds counted 'airing' out an 85ft. table-top.

                        Comment

                        • #13
                          Originally posted by motoman View Post
                          considered carbon-fiber?.
                          Never thought of that. I wonder how the binder would hold up to modern gasoline.
                          80 MNS; 80 F; 82 Maxim 650

                          Comment

                          • #14
                            Any link or attachment for fuel injection write-up?

                            I plan to microsquirt another XS11 I'll be getting and turbo it hopefully,
                            but I am very eager to find throttle bodies with fuel injectors and an acceptable mounting option that can hold some boost, and hopefully a more reasonable option than what I've found available new [~$820 in (4) 34mm throttle bodies w/ 248g/min fuel injectors] http://www.ecotrons.com/files/ECOTRO...cal%20spec.pdf

                            Comment

                            • #15
                              Originally posted by shutchis View Post
                              I`ve EFI`ed two bikes; a 1980 XS1100 and an 82 XJ1100 using Megasquirt. I've got over 40k miles on them in 9 years and they still run great. Even with alcohol fuel. I let one sit in the garage for over a year and it started right up. In my mind, EFI`ing these bikes was the best mod I ever made. The other mod was swapping out the differentials. I will never use carbs again; too much maintenance.

                              I posted my work on the XS11 forum under fuel modifications, but the web host I was using closed down earlier this year. I'll rework the write-up and make it into an attachment.
                              I made a copy of Stan's website a while back in case it went down as it is at this point. If you are interested in Stan's website pioneering into the world of XS1100 fuel injection, you can download the zip file containing the full site rip I saved in 2012.

                              http://xs11.planneddigital.com/wp-co...FI-Project.zip

                              The zip file contains a XJ1100 EFI Project directory that contains the full site rip with all of the images, etc.

                              82J · 81SH · 79SF Fire Damage · 78E · 79F Parts Bike · 04 Buell Blast
                              Website/Blog

                              Comment

                              Previous 1 2 template Next
                              Working...
                              X