Tag: 1989 Honda PC800 Pacific Coast

PC800 re-measured: 36mm inner, 42mm outer.

V-Strom 1000: 45 mm throttle bodies

V-Strom 650: 39 mm throttle bodies (or are they 42mm TB’s? seems they are 39mm…)

Moto Guzzi Breva: 37 mm?

Kawasaki Vulcan VN1700: 42 mm? (note that this looks really nice because the connection between the engine and the throttle bodies can be removed and replaced with something different that I machine myself. downside is it’s fairly rare.)

Honda VT-1300: 38 mm (only one on the bike!?)

Honda VT-750 Phantom: 32mm (only one on the bike?!)

CAN AM 800 (2009 model) ATV with some sort of throttle body that might work…

Sportsman Polaris 800 or 850

Dodge Neon has a 50 mm TB.

Fuel Pump stuff:

Seems like just about any 80s Toyota or BMW fuel pump will work because they’re all external pumps. Like a Toyota Celica pump. You can get them on EBay for 45 bucks in the right flow rate.

Note: Derek Duncan has a MegaSquirt simulator I can borrow.

Need to find a proper tilt sensor for motorcycle fuel injection pumps.  Might be able to scavenge one off of a motorcycle harness.

Will have to decide between modifying the fuel tank to accept an internal pump or having an external pump after the existing pump (low pressure then high pressure pump) with a surge tank.  Also should put in an accumulator or something similar which can be done with a T off the fuel line past the high pressure pump and some rubber hose.

Looks like the V-Strom 650 throttle bodies have dual butterfly valves.

how to do IAC valve control with an MS-I http://www.msextra.com/doc/ms1extra/MS_Extra_Hardware_Manual.htm#Fidle

The spare set of carbs from Phil came in the mail yesterday.  They are making my lab smell pleasantly of gasoline and solvent.  One of my labmates is also a gearhead.  He’s loving it.  The others aren’t saying anything yet.  I guess that gas smell hasn’t traveled all the way down the lab.

Taking some measurements from the carbs, I found the following:

Throttle body outlet measurements:

• Outer diameter: 40mm
• Inner diameter: 37mm

Throttle body inlet measurements:

• all wonky because they are tapered to receive the plastic airbox

I’ve been poking around looking for 37mm inner diameter throttle bodies with sensors and fuel injectors already installed but have come up short.  It seems like the Moto Guzzi Breva 750 throttle bodies might be the right size.  There is an auction on ebay for a set.  They have a sensor but don’t have any injectors as far as I can tell.  There is also a Suzuki Burgman 400 throttle body that ebay indicates might be the right size.  Looking at the microfiche, the Burgman does have fuel injectors.  I wonder if anyone on the IPCRC might have an extra set laying around…  The microfiche doesn’t tell me enough to figure out what angle the injector body is at compared to the throttle body and if the throttle body has any strange turns like the fuel injected VT750 throttle bodies do.

My google-fu is obviously weak because I haven’t had any luck finding a list of throttle bodies for common vehicles and their dimensions.  Does anyone know where I might be able to find such a list?

A friend recommended I pick up a copy of Four-Stroke Performance Tuning as I get ready to put fuel injection on my PC. That’s the book that he used 10 or so years ago when he put FI on a Datsun engine. He also suggested that I might point the injectors up toward the plenum to improve atomization.

One person on the IPCRC suggested that I fit a vacuum-operated fuel regulator to decrease flow to the injectors at high vacuum (low RPM). I need to investigate this more to see if this would be worthwhile to pursue or if modern injectors can give me precise enough fuel delivery for lower RPM operation.

It seems that there are two types of injectors. One is standard and the other is a pico injector. Picos use less power according to someone on the IPCRC. That is good for our power-starved PCs.

This project will be taking a back seat for the next month or two as I have several conference papers to produce in short order. Hopefully by June I will have some plans put together and parts ordered. I’d like to go to next year’s TGPCHPCMY2KMR+11 ride with working fuel injection. And a rear rack. 🙂