04 Derbi GPR Nude

[Basscor]

Hmm after thinking it over, I think that I want to get it back to stock rather than upgrading. I like having the low fuel light since there is no reserve.

Looks like this is what I want from Easy parts: http://www.easyparts.nl/showdrawing/166 ... 30-d211120

Unless there us a US source for OEM parts?

[toratora]

Yeah some of the modern improvements aren’t always for the best.

Easyparts is a great place to find the oem parts. They are on the list of good venders. Usually when I order from them I’ll get a bunch of stuff. This helps mitigate the expense of the shipping. They also offer shipping it to a local pickup spot which lowers the shipping cost a little bit. I’ve found EZ to be very responsive to questions, and customer service. I highly recommend them.

[jkv357]

That's what I was afraid of, I already tried sucking on the bottom one. No fluid out either hose

As for a replacement, the OMG one looks alright. If I choose to go for the screw operating version, what do I need to do to the vacuum barb on the carb? Take it out an replace with a screw I suppose? Or just save the hassle and stick with a vacuum petcock?

You found your problem.

Does anyone make a rebuild kit for the petcock?

Do you have ethanol-free gas available? I do, and always avoid ethanol in all my cycles and small engines, but I realize it's not available in some areas.

I agree to stay with the stock petcock if you can. They really put a fuel gauge in the petcock? First I've heard of that.

[Basscor]

Its less of a gauge and more of a warning light

[toratora]

It appears that Racing Planet stocks these petcocks in an aftermarket version.

[Basscor]

Life has been a bit hectic lately so I haven't made as much progress as I wanted.
I did order the petcock form easy parts and got it installed. I now have fuel getting to the carb and through it.

The next problem is that it will still not start. My next step was to check for spark. biggest problem is that the starter motor system seem to be intermittent or shot. At this point it will usually spin but not engage with the "flywheel" (seems to be the magneto cover). So my current method to turn it over is to bump start it, which isn't working and is exausting.

Next concern is that the piston seems to be intermittently locking up. I'm hoping at this point I have just accidentaly flooded it.

[toratora]

When you have more than one issue the best method is to work on them one at a time methodically plodding through each one until you solve them all.

From what you are saying I would inspect the cylinder first. It isn’t very difficult to remove the cylinders on these bikes. My project threads are full of such efforts. If you have seized the engine, then none of the other issues will matter until the top end is properly set up. After pulling the top end make sure to do a leak test after reassembly.

Other options include employing a bore scope, or even pulling off the pipe, and inspecting via the exhaust port.

Sometimes with the starters the battery is too weak to engage them. This usually happens on these bikes because the stator doesn’t produce a good enough charge. Presently most of my GPRs have the starter removed. I GP start all the time.

But also, things get dirty, and just removing them, cleaning them, lubing them, etc. has a tendency to keep things working properly.