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Discussion Starter · #1 ·
Will someone please help a biker in South Africa? I've got this 1983 CX 500 Turbo and well, if they are rare in the USA then you can imagine they are even more so here.

The bike has various faults (although it looks great), most of which I can fix, as the local mechanics don't want to touch it, but for some reason the turbo doesn't kick in like I think it should. It's like riding a normal 500.

The turbo itself has been overhauled and I have fixed various exhaust leaks. The motor idles beautifully, you can hear the turbo spinning, and the turbo indicator on the dash shows boost but there isn't any to speak of. The muffler is non standard but I can't imagine that's a problem. The turbo repair guy reckons it's maybe fueling that is the problem but I do not know enough to believe him or not. Anyone help?

I also need a new ignition switch. And it's slightly overheating but I imagine that's the fan switch or Thermostat. Help please! Oh and by the way Honda SA do not seem to be equipped with diagnostic equipment.
 

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Will someone please help a biker in South Africa? I've got this 1983 CX 500 Turbo and well, if they are rare in the USA then you can imagine they are even more so here.

The bike has various faults (although it looks great), most of which I can fix, as the local mechanics don't want to touch it, but for some reason the turbo doesn't kick in like I think it should. It's like riding a normal 500.

The turbo itself has been overhauled and I have fixed various exhaust leaks. The motor idles beautifully, you can hear the turbo spinning, and the turbo indicator on the dash shows boost but there isn't any to speak of. The muffler is non standard but I can't imagine that's a problem. The turbo repair guy reckons it's maybe fueling that is the problem but I do not know enough to believe him or not. Anyone help?

I also need a new ignition switch. And it's slightly overheating but I imagine that's the fan switch or Thermostat. Help please! Oh and by the way Honda SA do not seem to be equipped with diagnostic equipment.


If the fuel system light is coming on the dash it goes into "safe" mode. You need to read the codes on the computer while leaving the key on. Once you know the codes you can fix the problem and achieve full power.



PK
 

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Discussion Starter · #3 ·
If the fuel system light is coming on the dash it goes into "safe" mode. You need to read the codes on the computer while leaving the key on. Once you know the codes you can fix the problem and achieve full power.



PK
Thanks for this. When I turn on the ignition I get a neutral light and an oil light, which obviously goes off when starting, and I presume this is correct. The fuel system light does not come on at all. Please see above, no-one in this country seems to have diagnostic equipment for this bike, or is it the same equipment that current Hondas use?
 

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Thanks for this. When I turn on the ignition I get a neutral light and an oil light, which obviously goes off when starting, and I presume this is correct. The fuel system light does not come on at all. Please see above, no-one in this country seems to have diagnostic equipment for this bike, or is it the same equipment that current Hondas use?


Check the fuel filter and petcock to make sure fuel is flowing out properly and not clogged...
 

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From his thread in another forum it sounds like the wastegate is stuck open.



I know nothing of the turbos CX's, can someone explain to him how to check for that?
 

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The diagnostic equipment consists of a pressure pump/gauge, a vacuum pump/gauge, a wire harness to test the sensors, a multi-meter, and one other thing I can't remember off the top of my head.



Mity Vac makes compatible pressure and vacuum gauges. Any multimeter will work.

I can e-mail you a copy of a sensor testing harness that HomerRod made.

Those tools should be more than enough to get you through 90% of the problems you can face with the bike.
 

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The fuel system light is supposed to turn on for 2 or 3 seconds when you turn the ignition key to on. If your bike has the emergency cut off switch as used on US models, it also needs to be on.

If it doesn't light up then the bulb is out or a wire is cut. The ECU in the tail piece has LEDs on one side that report faults. When a fault occurs it tells you by turning on the fuel system light. If the fuel system indicator bulb is out you may have a fault code and not know it.
 

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Discussion Starter · #8 ·
Hi Guys, I'm back. OK the fuel light comes on for maybe one second when the ignition is switched on with the engine kill switch in the "run" position, and I can hear the fuel system pressurising, so I take it that is all correct. Also with the ignition on none of the lights on the control unit light up (W 1 2 3) except that the W lights up for about a second when the ignition is turned on also, which also seems correct.



Am I right in thinking that this all points to a stuck waste gate and if so is there a way of checking/fixing that without fairing removal or have I got to do that again:-(



Thanks for the help so far! I would really like to get it on the road while it's still summer here!
 

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"A bottle of Mouse Milk from Aircraft Spruce, a squirt bottle to shoot the Mouse Milk at the wastegate armature, (soak the armature and let it sit overnight if you can), and an open end wrench that fits over the armature, work it back and forth for a while, and you can cure it permanently. You don't even have to take the fairing off to do this (just the screen that protects the radiator)."



Solve a stuck wastegate
 

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Hi Guys, I'm back. OK the fuel light comes on for maybe one second when the ignition is switched on with the engine kill switch in the "run" position, and I can hear the fuel system pressurising, so I take it that is all correct. Also with the ignition on none of the lights on the control unit light up (W 1 2 3) except that the W lights up for about a second when the ignition is turned on also, which also seems correct.



Am I right in thinking that this all points to a stuck waste gate and if so is there a way of checking/fixing that without fairing removal or have I got to do that again:-(



Thanks for the help so far! I would really like to get it on the road while it's still summer here!




If you have a stuck waste gate the bike will give you the ride of your life the first time you roll open the throttle after starting it. The raped ape ride will last a few moments then you'll see the far end red bars on the boost gauge light up and the word turbo will start flashing. At that point the fuel light will turn on, a fault code will be set in the computer and performance will be lost as the bike goes into fail safe mode.



If none of that is happening then most likely you don't have a stuck waste gate. I say most likely because there could be a chance it's stuck open but I've never heard of that happening.
 

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One of our turbo owners here in Oz had a very similar thing happening to his turbo - turbo obviously OK, but no boost.

Check that ALL the pipes and hoses from the turbo's compressor to the inlet manifold, resonator box and impulse-damper box are properly connected, and that ALL hose clamps are tight.

These hoses are not easy to check (you certainly have to take the fairing off for this check, and may need to take one or more of the internal heat shields off to check every connection).

In this guy's case it was a displaced pipe from the compressor to the main air-chamber on the inlet system - one of the short rubber joints had become disconnected, due to the clip not being properly placed.

Some people replace these clips with worm-drive hose clamps, and the "all stainless steel" variety are much preferred here.
 

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If that wastegate stuck open....well it could stick closed too if you dont get it free/hence overboost...I would take the "c" clip off of the arm and work the turbo bypass back and forth and inspect the actuator.
 

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I don't have a turbo cx but i have a turbo mazda mx6.....



I had a turbo that had a bad bushing in the exhaust flange causing the turbo i rebuilt (except that part) to have a stuck wastegate. I torched it thinking it was rust causing the linkage to stick and then i would oil it down. This would work for about a day and then it would do it again. I was at the turbo shop having another assembly balanced and mentioned this issue and they said the bushing due to heat and age was probably bad.



Thankfully that turbo never made it on the car but if your wastegate is frozen open your instantly going to take a while to reach full boost since it will have a leak causing the turbine not to spin fast enough. I'm sure instantly it will reach full potential but i'm sure it would take a long WOT for it to spin up. But then these are small turbo's so maybe i'm full of ****. But the mx6 turbo uses a IHI VJ11 which is pretty small as well so i could see this a little.
 

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What with the non-stock muffler and various exhaust leaks, are you sure all the pressurized plumbing on the input side is present and accounted for? If it isn't a seating problem with the waste gate and the turbo is pumping, where is the pumped air going? Check the pressure and volume of your fuel pump output to see if it is up to specs.
 
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