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PPMPR: Project Poor Man’s Pro Race

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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:

Project Poor Man’s Pro Race: There was a Visit to Treats

Post by toratora » Thu May 16, 2019 9:39 pm

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The ProRace kit came in so a visit to Treats was in order.


The new kits are very different from the previous ProRace kits. There are some similarities, but it seems there have been slight changes to every part, and the quality seems to have gone down a notch. One nice improvement is the coated piston.


I was happy to see they didn’t employ the evil clips. I know why the non-handle clips are preferred, but I have a hell of a time installing them. These half handled versions are difficult enough.


The heads use to be anodized gold. Now they come in a color that ranks right up there with the Aprilia RS 50 wheels for most like the color of shit. I know these photos don’t really illustrate it, but it really does look like a shade of shit.


They also switched to a five port transfer design. It would seem like less fuel can make it into the chamber. Too bad I didn’t have time to do a port map this time around.


The exhaust port is quite rough, and requires much attention. :paw_prints:

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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:

Project Poor Man’s Pro Race: Going Full ProRace

Post by toratora » Sat May 18, 2019 9:39 pm

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Time for this bike to actually have a ProRace kit!


Setting up the word space.


Removing the Stage6 kit.


Pulling the head and inspecting it revealed why the engine had issues. The head has a manufacturing defect that caused it to split a piece off allowing compression to escape into the cooling system.


The piston had a very nice wash indicating that the tuning was close. This is very interesting because the bore scope showed the piston to have basically no wash.


The cylinder had some slight scoring. Probably caused by hot gases escaping into the cooling system.


The prepped ProRace cylinder going on the bike.


With everything together I noticed that the water pump weep hole was leaking. Could be fallout from cylinder pressure blowing into the cooling system. That will need to be handled before riding the bike. I did try to start it up. It nearly ran, but couldn’t quite fire over. I need to look into that more, but the rain was coming, and I had to button up the bikes.

I also want to check out the top end of the Silver bike to see if it too has suffered from a failed head. That would explain a lot. :paw_prints:
3 x

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kaldis12
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Location: Hungary
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Re: Project Poor Man’s Pro Race: Going Full ProRace

Post by kaldis12 » Sun May 19, 2019 1:30 pm

toratora wrote:
Sat May 18, 2019 9:39 pm

Pulling the head and inspecting it revealed why the engine had issues. The head has a manufacturing defect that caused it to split a piece off allowing compression to escape into the cooling system.
What did I just say earlier? :D
I was right man :D
2 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:

Project Poor Man’s Pro Race: O-Rings

Post by toratora » Sun May 19, 2019 1:39 pm

kaldis12 wrote:
Sun May 19, 2019 1:30 pm
What did I just say earlier? :D
I was right man :D
Somehow I don’t think a new o-ring is going to fix this one!! :scream_cat:

Also, check out the head on the Silver bike. Very similar conditions, and the head looks new. :paw_prints:
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kaldis12
Posts: 260
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Location: Hungary
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Re: Project Poor Man’s Pro Race: O-Rings

Post by kaldis12 » Mon May 20, 2019 2:12 am

toratora wrote:
Sun May 19, 2019 1:39 pm
Somehow I don’t think a new o-ring is going to fix this one!! :scream_cat:

Also, check out the head on the Silver bike. Very similar conditions, and the head looks new. :paw_prints:
Maybe not a new O ring :-D, but I was digging at the right place :D

The Silver Bike looks like what I was dealing with. I took off the head and I saw no indication that the O ring were blown or anything, just on the cylinder wall.
I would say that the Silver Bike has a head issue too. It looks like that Stage6 cannot really make a cylinder head.

Do you have an indicatot gauage? You could check it, if its bent or not. If yes, then a truing can fix it easily.
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:

Project Poor Man’s Pro Race: Vinyl Aspirations

Post by toratora » Mon May 27, 2019 9:39 pm

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This is the look that I’m aiming at. It is the 2001 Ui replica livery. I really wont be able to totally achieve it so I decided to employ my artistic license.


Ed is helping me move forward with this project. He was able to take my modified designs, and cut some vinyl with them. So far it looks like they will work swimmingly! :paw_prints:
2 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:

Project Poor Man’s Pro Race: Cry Me a River

Post by toratora » Tue Jun 04, 2019 2:39 pm

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The last time I had a chance to work on this bike I was trying to get it ready for the 19-19 Redux. I totally failed for a number of reasons. One of which is that I didn’t have the proper resources to deal with the removal of the stock cylinder studs, and install the slightly longer (5mm) Metrakit studs. That issue was ameliorated with a parts order from Treats! :ghost:


Due to the shorter studs I was not able to achieve proper torquing of the head. This created enough of a coolant leak that created a serious dihydrogen monoxide issue as is illustrated with these photos of the River of Chamber.


This meant that I was going to have to remove a bunch of stuff in order to deal with the issue.


All the gaskets and o-rings looked fine, and appeared to have been installed properly supporting the hypothesis that there just wasn’t enough torque on the head.


There was going to be a lot of clean up work! :scream_cat:


Starting with the removal of the stock cylinder studs.


It was quite messy in there! :scream_cat:


I also found some fibaa in there which meant a failed reed valve. Upon removal of the intake it was clear that the Malossi reed had failed. I did’t find all of the fibaa, which means some of it probably made it into the pipe.


The Metrakit cylinder studs are about 5mm longer than the stock studs. They were set with some thread lock, and installed.


The cylinder was installed, and torqued to ~19NM. Then I checked the squish, but the 1.0mm diameter solder I have was not squished at all. So I know it is at least 1.0mm!! :grimacing:


Next up was the leak test. There was a slight leak that could possibly be at the exhaust manifold. Unfortunately I didn’t have the bubbles handy, and it was getting dark so I had to pack it in. Elf needs garage badly!! :paw_prints:
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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:

Project Poor Man’s Pro Race: The Valdez

Post by toratora » Tue Jun 04, 2019 9:39 pm

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After enduring a learning experience with the Cobra I hoped to make some progress with the ProRace.


First up was to see where the pump was losing pressure. None of the typical suspects were in evidence. This could mean that the leak is at one of the main seals. Since I have to fix the water pump I’ll be able to check the clutch side, and the ignition side will require removing the stator, and I’m probably going to have to check that too.


I was able to drain the oil/water mixture, remove the clutch cover, and clean up most of the mess, but then it was getting dark, and I had to pack it in for the day. I should be able to clean up the cover, and replace the pump before going back out to the bike. Then I’ll probably pull the flywheel, and stator to make way to check the main seals for leaks. :paw_prints:
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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:

Project Poor Man’s Pro Race: Repair of the Pump

Post by toratora » Thu Jun 06, 2019 10:39 pm

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Today totally got away from me, but I was able to get the pump repaired, and will now be able to install it.


Usually I would pull the pin out at this stage, but it wasn’t coming out so I was forced to remove it from the outside.


With The shaft and impeller removed it was time to extract the seals. Note that the seals face each other.


This time I employed a MotoForce revision kit. The RM kits that I used in the past had shafts that were just slightly too large in diameter to fit into the cases. This kit did include the brass nut that secures the impeller to the shaft. Also, the impeller doesn't look as nice as the stock one. I probably should have continued to use the stock impeller. All of these replacement kits seem to come with solid pins. I don’t trust them to stay in the shaft. So I try to reuse the stock pin, which in this case I was able to do—eventually!


Note that one of the washers goes between the case and the gear. Also, these kits don’t come with gaskets. Usually you can salvage the case gasket like I’ve been able to do here, but the pump gasket frequently needs replacement. Next up installing the cover, adding some oil, and doing the heat cycles!! :paw_prints:
2 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:

Project Poor Man’s Pro Race: Temporary Defeat!!

Post by toratora » Fri Jun 07, 2019 3:39 pm

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I expected to start this bike up today, but first I had to check the main seals for leakage.


Sure enough there were bubbles. I ordered some replacement Polini seals from Treats. :paw_prints:
1 x

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