GPz 550 D1 carb choke flaps

Just got myself a GPz550D1 from a mate who got sick of it 'cus it has severe starting trouble from cold. He had been using the bike for a couple of years but previous to that it had sat for nearly 10 years, without being started and having been drained of fuel, after being imported into the UK.

I had a look over it and found it had sticking float valves. So I droped the carbs off and disasembled cleaned and reassembled the float valves and jets but while I had them off I noticed all 4 choke flaps were missing, I can see the end of the springs poking out the holes but no sign of any of the flaps.

The bike starts from cold now if I restrict the air intake with a rag while starting it and it seems to run well once warmed up. I have orderd some carb service kits and will do a full rebuild on the carbs when I have a bit more time.

My questions are, where can I get replacement choke flaps from and should I worry about where the other ones went if the bike runs OK? Do you think it is likley that the flaps were removed or that the engine has eaten them? If the latter what sort of damage would I expect to see if I do strip it down?

TIA for any help you guys can give.

B

Post edited by: bigbrett, at: 2005/11/27 17:41

Post edited by: bigbrett, at: 2005/11/27 17:42

I would like to know too, my 550 is missing them as well. Starting on a warm day is ok, but on a cold morning it is a pain.

Not sure where you guys can get flaps other than getting some 550 carbs on ebay. They have to be the TK-22 carbs. They were only on limited years.

I suppose you could also try making something, but that seems iffy at best.

If you get the flaps working, there are some tips for the 550 D1 on my website. One includes a mod on how to make the high-idle adjustment accessible from the side of the bike. This lets you change the high-idle with two fingers instead of taking the tank off etc. You can adjust it while running and change it as needed.

Now that I think about it, if you just block off the choke flap openings most of the way permanently, you might be able to get a decent cold-start and play with the choke lever (and aforemetioned high-idle adjustment) to get the bike warmed up. It would just take some experimenting.


www.geocities.com/loudgpz

Post edited by: loudhvx, at: 2005/11/27 23:28

Does anyone know what the choke gates are made out of? I have an aluminum welder at work, if they are aluminum I could fill the space with weld and leave a small opening at the bottom.

Not sure what they are made of, but the flaps were stainless I think. The gates might be some aluminum alloy or pot-metal casting.

You'll want to experiment with taping different size plates over the opening on the gate.

My GPZ550 was also missing the choke flaps, I picked up a rack of carbs off ebay for $15.

word of advice..don't get these things hot..they will turn to a molten mess. I guess I need to find a rack of used carbs that I can dismantle.

DasTeufel wrote:

word of advice..don't get these things hot..they will turn to a molten mess. I guess I need to find a rack of used carbs that I can dismantle.

Uh oh! Those sound like words from experience.

lol yes it is. I was attempting to solder a piece of thin metal to the pin, next thing I know the bottom edge of the gate vaporized. I only tried it on one, wasn't about to ruin the rest. It is definitely pot metal.

If you can't get a set of gates with flaps and you still want to try tinkering with sealing the gates up, I have a spare gate I can send you (no flaps though).

Thanks man, I appreciate it. I'm trying to find a rack of carbs right now, there is one on ebay right now, but I'm not paying 50 bucks plus shipping.

Here's a thought (uh oh)

Would it be possible to make a casting of the gates then cast your own? If so, how should I go about this? It could prove invaluable to owners of KZ/GPZ 550's with missing choke flaps, should it work. Since pot metal has a relative low melting point (trust me, I know :pinch: ), I was thinking of making a casting with plaster of paris, split it, then make my gates using molten pot metal (where I will find this, I dunno). Worth a try?