Support GPR Camp!!

Derbi GPR 50 Belson project

Create a thread about your bike.
User avatar
Berkeley
Posts: 297
Joined: Sun Sep 02, 2018 5:24 pm
x 332
x 147

Re: Derbi GPR 50 Belson project

Post by Berkeley » Tue Nov 06, 2018 10:21 pm

Hi mate.. I'm upgrading a 2018 rs4 50 and selling all the standard parts including a bunch of indicators etc. If you need any then drop me a line cheers
1 x

User avatar
toratora
Posts: 3161
Joined: Wed Oct 11, 2017 1:05 am
Location: San Francisco
Replica: Derbi GPR
Cagiva Mito
Cobra CX65
Aprilia RS50
x 1768
x 1977
Contact:

Derbi GPR 50 Belson project: The Air Box

Post by toratora » Wed Nov 07, 2018 12:23 am

Berkeley, pretty much everything that you are replacing wont work on his bike. The models change significantly in 2010. The engine is fairly similar, but the Euro4 stuff changed many things that might have been interchangeable. I would also caution you to keep spars laying around. They can come in very handy!

Mace, I finally figured out what you were talking about. This is why photos are so valuable. :?

The part of the air box you are talking about is removable. The stock 50 wont run if you remove it. However, if you kit the bike you have to change it. One way is to get the part from the 125 2T bike. I've done this, and somewhere in the DRP thread there is information on it. But if you don't want to get that part you can do what I initially did with my bike.

Remove the plug, and replace it with some radiator hose. You can get some that will snuggly fit the hole in the air box. I then employed a zip tie to keep it in place. It worked quite well, and there might be a photo of it in the DRP thread, but I probably had upgraded the air box by then. I'll hunt around for photos, and update this post if I find them. ;)

For jets just buy the Polini ten packs. They are high quality parts, and when tuning they make you life much easier. They make them for the PWK style, and the Dellorto style.

I am so envious that you have a friend with a dyno to tune your bike. :shock:

Oh yeah the petcock. I've not had this problem myself, but I remember Patrick talking about it on AF1. It seems that some of the tanks were made poorly, and had an issue with that plastic part failing. From what he said there was no way to replace it. But I can't really believe that there wouldn't be a way. Some sort of sealer should do the job. That or pick up a used one. I actually bought a brand new tank with your bike's livery when my bike was run over. I've never used it because it's yellow, and I found removing the gas cap difficult. However, for the same reasons I mentioned to Berkeley you never know when spares will come in handy. ;)
1 x

User avatar
mace
Posts: 60
Joined: Fri May 04, 2018 3:27 pm
x 1
x 24

Re: Derbi GPR 50 Belson project

Post by mace » Wed Nov 07, 2018 1:20 am

Berkeley wrote:
Tue Nov 06, 2018 10:21 pm
Hi mate.. I'm upgrading a 2018 rs4 50 and selling all the standard parts including a bunch of indicators etc. If you need any then drop me a line cheers
Cheers mate, I'm pretty much sorted on the parts now, thankfully. :)
0 x

User avatar
mace
Posts: 60
Joined: Fri May 04, 2018 3:27 pm
x 1
x 24

Re: Derbi GPR 50 Belson project: The Air Box

Post by mace » Wed Nov 07, 2018 1:35 am

toratora wrote:
Wed Nov 07, 2018 12:23 am
Mace, I finally figured out what you were talking about. This is why photos are so valuable. :?
Image
2006 Derbi GPR 125 2T Air box
Yeah yeah, I know. It's just a bit of a pain to upload photos, so I didn't. :D

There you go. Part #9 on that diagram (this is the 125 version). Thanks for the pointer, I'll try and find one of those. :)

Part numbers for posterity. 50cc diaphragm is 00H01800621, 125cc is 00H01801621.
toratora wrote:
Wed Nov 07, 2018 12:23 am
The part of the air box you are talking about is removable. The stock 50 wont run if you remove it. However, if you kit the bike you have to change it. One way is to get the part from the 125 2T bike. I've done this, and somewhere in the DRP thread there is information on it. But if you don't want to get that part you can do what I initially did with my bike.

Remove the plug, and replace it with some radiator hose. You can get some that will snuggly fit the hole in the air box. I then employed a zip tie to keep it in place. It worked quite well, and there might be a photo of it in the DRP thread, but I probably had upgraded the air box by then. I'll hunt around for photos, and update this post if I find them. ;)
Good idea.. I'll try that if I can't get the stock part, ta.
toratora wrote:
Wed Nov 07, 2018 12:23 am
For jets just buy the Polini ten packs. They are high quality parts, and when tuning they make you life much easier. They make them for the PWK style, and the Dellorto style.
I'd already ordered some from a UK supplier before I saw your reply. They claim to be UK made to some half decent standard, we shall see, the fact the packs are 10 jets with no gaps (ie. 95, 96, 97, etc) suggests they have at least a small amount of confidence in their tolerances–most kits I've seen are 95, 100, 105 etc.
toratora wrote:
Wed Nov 07, 2018 12:23 am
I am so envious that you have a friend with a dyno to tune your bike. :shock:
Have to pay for the pleasure, but yeah, it was useful to see the fueling, even if overall it was fruitless (until I get more parts to swap about). Long ride on an unhappy bike in the rain/dark to get back though :(
toratora wrote:
Wed Nov 07, 2018 12:23 am
Oh yeah the petcock. I've not had this problem myself, but I remember Patrick talking about it on AF1. It seems that some of the tanks were made poorly, and had an issue with that plastic part failing. From what he said there was no way to replace it. But I can't really believe that there wouldn't be a way. Some sort of sealer should do the job. That or pick up a used one. I actually bought a brand new tank with your bike's livery when my bike was run over. I've never used it because it's yellow, and I found removing the gas cap difficult. However, for the same reasons I mentioned to Berkeley you never know when spares will come in handy. ;)
I read something about it somewhere, but failed to find the right search terms to find the topic again. Wasn't even sure which forum I'd seen it on. The plastic part can be removed/replaced, as I've had mine out (don't ask). It's a bit fiddly to tighten back up if, like me, you can't remove the filler assembly because the captive nuts are insufficiently captive now and spin. :lol:

You lock the internal nut using a large hex key–I used a hex socket on a universal joint and socket extension in order to reach in through the filler hole. Tight, but quite achievable.

There are two o-rings in the tank fitting from memory. Suspect the smaller of them has had it in mine, but I'll try replacing the petcock with a new one I have waiting (don't ask :lol:) in case the o-ring on that was damaged on last assembly.

Don't suppose you want to part with that tank to the UK? :lol: Mine has definitely seen better days, paint is cracking on it etc. :(
1 x

User avatar
mace
Posts: 60
Joined: Fri May 04, 2018 3:27 pm
x 1
x 24

Re: Derbi GPR 50 Belson project

Post by mace » Wed Nov 07, 2018 5:45 am

Took the tank fitting out again, cleaned the o-rings, soaked them in boiling water so they could regain whatever shape they could, lubed them with petrol and reassembled with the new petcock. So far, dry.
1 x

User avatar
toratora
Posts: 3161
Joined: Wed Oct 11, 2017 1:05 am
Location: San Francisco
Replica: Derbi GPR
Cagiva Mito
Cobra CX65
Aprilia RS50
x 1768
x 1977
Contact:

Derbi GPR 50 Belson project: Fiddly

Post by toratora » Wed Nov 07, 2018 11:39 am

There is a tutorial on how to do photos. ;)

Shipping the tank over here from Europe was rather expensive. It would probably save you lots of euros to find one on that side of the pond. I just bought a white tank in Japan, and that shipping was more than the cost of the tank.

I ended up getting the whole 125 air box because the first 50cc air boxes used snaps to hold the cover on to the box. They didn't function very well at all, and the 125 box employs screws. They work much better.
0 x

User avatar
mace
Posts: 60
Joined: Fri May 04, 2018 3:27 pm
x 1
x 24

Re: Derbi GPR 50 Belson project

Post by mace » Thu Nov 08, 2018 5:56 am

Hi Toratora,

I was mostly joking re tank. :)
The hard part of image posting is me having a camera in the right place at the right time, then getting time to get the photos off the camera and on to my online photo hosting. :lol:

My 50cc air box has screws; I guess they must have changed the design at some point?
No luck yet in finding one of these plugs on ebay.. the hunt continues.
0 x

User avatar
toratora
Posts: 3161
Joined: Wed Oct 11, 2017 1:05 am
Location: San Francisco
Replica: Derbi GPR
Cagiva Mito
Cobra CX65
Aprilia RS50
x 1768
x 1977
Contact:

Derbi GPR 50 Belson project: The Image

Post by toratora » Thu Nov 08, 2018 11:39 am

For nearly all of the photos I post they are taken with cell phones. Sometimes I will post images made with the bore scope, and very seldomly I'll employ a "real" camera. Sometimes I may get stills from an action camera like a GoPro, or Contour, but for the most part it's all cell phone action. :?

It is nice that they upgraded the air box on the 50s. I doubt that you'll find the adapter part on eBay. Maybe a 125 air box will show up. Easy Parts should be able to source it though, have you tried them? Yup they do, it's even in stock for only 5€.
0 x

User avatar
mace
Posts: 60
Joined: Fri May 04, 2018 3:27 pm
x 1
x 24

Re: Derbi GPR 50 Belson project: The Image

Post by mace » Mon Nov 12, 2018 7:29 am

toratora wrote:
Thu Nov 08, 2018 11:39 am
For nearly all of the photos I post they are taken with cell phones. Sometimes I will post images made with the bore scope, and very seldomly I'll employ a "real" camera. Sometimes I may get stills from an action camera like a GoPro, or Contour, but for the most part it's all cell phone action. :?
Ok, so I'm just lazy :lol:
toratora wrote:
Thu Nov 08, 2018 11:39 am
It is nice that they upgraded the air box on the 50s. I doubt that you'll find the adapter part on eBay. Maybe a 125 air box will show up. Easy Parts should be able to source it though, have you tried them? Yup they do, it's even in stock for only 5€.
I was hopeful that they had new stock in, but that part is actually the 50cc version.

I have a love/hate relationship with easyparts.. I like their site mostly and the selection and prices are good, but why they can't show the manufacturers part number I don't know. You have to view the HTML source on the part you're interested in, and dig through for the actual part number, which is insane.

125cc air box adapter
0 x

User avatar
toratora
Posts: 3161
Joined: Wed Oct 11, 2017 1:05 am
Location: San Francisco
Replica: Derbi GPR
Cagiva Mito
Cobra CX65
Aprilia RS50
x 1768
x 1977
Contact:

Re: Derbi GPR 50 Belson project

Post by toratora » Mon Nov 12, 2018 8:39 am

I agree on that criticism. It's rather frustrating when you know the part number, but also it would be nice if they would just show it. I didn't realize that it was in their HTML though. It appears four times in the linked page. Here's a code snippet. It probably wouldn't bee too difficult to create some python code to scrape the page. I'll have to think about it a bit, but we could always just start writing to EZ and ask them to display the number. Clearly they already have it. ;)

Code: Select all

 				<input type="hidden" name="extrainfo">
					<input type="hidden" name="extrainfo2" value="">
					<input type="hidden" name="action" value="ADD">
					<input type="hidden" name="modelid" value="2928">
					<input type="hidden" name="partid" value="00150[color=#FF0000]0H01801621[/color]">		
					<input type="hidden" name="grouppath" value="0-4019-1-m414-m1008-m2926-m2928-s2933-d49518">
					<input type="hidden" name="universal" value="">
					<input type="hidden" name="may_not_fit_model" value="0" />
					<input type="hidden" name="submit_in_background" value="1" />									  
				</form>
0 x

Post Reply