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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
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Project Poor Man’s Pro Race: Seals

Post by toratora » Tue Jun 11, 2019 3:39 am


I did a SWAT order for the main seals from Treats. It’s quite a process to change out the seals, so there are a lot of photos for this post. It has been very hot around here recently so I had to avail myself of the umbrella girl again.


The first step was to remove the clutch basket. The Lisel works well for this, because otherwise it’s really easy to strip out the Philips screws. It doesn’t take much force with the hammer. Really it is more about keeping the driver from popping out while it turns.


With the clutch basket removed, and the main pinion gear the seal can be pulled out.


Next up was the flywheel side. About this time German came by with the DeWalt. I really have to get me one of these! Before the puller can be employed the washer needs to be removed. Lightly tapping on the flywheel with a hammer usually is enough to get it to fall out.


It is very important to thread the puller in all the way so as not to damage the threads on the flywheel. To remove the stator the Lisel works great. The the stater plate can be removed gaining access to the seal.


I was quite disappointed to see that the crank had developed some surface rust. Some 400, then 1200, and a green pad cleaned this up nicely. I hadn’t tested the seal on this side to see if it was bad, but since the other side tested bad I didn’t want to take the risk, so I just replaced both. It was extra work, but I was already this close, and it was better to be sure things were proper.


I noticed that the spring of the clutch side seal remained on the crank shaft. I don’t know if that has occurred during the removal of the seal, or was part of the failure. Either way it was nearly time to install the new seals. Again I went with the very expensive Polini seals.


Getting the seals in place.


With the new seals in place I had to test them. They passed. I did find out that my pump is leaking, which I thought was the source of the remaining loss of pressure. I would find out later that were was another issue!


To install the gears I first applied some thread lock. Then put the main gears on finger tight, aligned the marks for the balancer, then put the clutch basket in place. At this point it is all had tight. I would have to secured the clutch basket before being able to torque the main gear.


The clutch basket I was able to torque by putting a socket on the output shaft. For the main gear once the clutch basket was secured I could employ the unorthodox method of locking the gears with a screwdriver. This works well enough, and I’ve never had a problem employing this method. I was unable to locate my piston stop, so I had to get creative. :zipper:


There is a trick to installing the pressure plate. Align the marking to the top spire. If incorrect there will be a large gap, if correct it will sit flush. Then the screws may be installed. I usually use a radial pattern to keep the tension even.


With the pressure plate in place I could then attend the stator. First aligning the mounting plate, then installing the stator.


Then the flywheel could be installed and torqued. Again I used some light thread lock. Also pictured here is the trick of placing a socket on the output shaft. It also helps to hold the front brake when torquing the nuts, as the bike has a tendency to move when a large lever is placed in such a position. Then I replaced the front sprocket. By this time it was dark out, and I had to pack it in. :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 Deliverator

Post by toratora » Thu Jun 20, 2019 3:39 am

It was an incredibly hot day for San Francisco. Way too hot to be wrenching, but the wrenching needed to get done.

Unfortunately getting done wasn’t a possibility for this project—there were just too many things sending it sideways.
.
First up was getting the clutch cover installed.


Then about 650ml of Motul Transoil.


Then the coolant hoses, and adding some coolant—which in this case was distilled water.


At that point it was time to install the pipe. Usually the pipe gets installed a bit earlier, but this time it didn’t because the pipe was in the house. I went to retrieve it to find a water puddle on the ground. Upon inspection I discovered that the water jacket was leaking into the exhaust port, and this was the reason way the expansion chamber had filled up with water.


After speaking with a number of folks it seemed like JB Weld was worth a try. So I went to pick some up at the local auto supply store. After cleaning up, and employing a de-cottened Q-Tip to apply the epoxy the cylinder would then require 24 hours of curing time. So this project was set aside for the time being, and other bikes became the subject of attention. :paw_prints:

Image
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kaldis12
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Location: Hungary
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Re: PPMPR: Project Poor Man’s Pro Race

Post by kaldis12 » Thu Jun 20, 2019 7:23 am

I hope that the JB Weld will work well for you. The last time I tried the JB Weld solution the pressure and temperature just blew it out.
After a lot of messing I just welded it in. I wasnt able to find a better solution.
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jkv357
Posts: 228
Joined: Fri Dec 01, 2017 6:47 am
Location: WI
Replica: '99 GPR EBE-075
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Re: PPMPR: Project Poor Man’s Pro Race

Post by jkv357 » Thu Jun 20, 2019 8:53 am

I can't tell where the problem was.

Was it a crack?
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
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Project Poor Man’s Pro Race: Omizu desu

Post by toratora » Thu Jun 20, 2019 9:39 am

kaldis12 wrote:
Thu Jun 20, 2019 7:23 am
I hope that the JB Weld will work well for you. The last time I tried the JB Weld solution the pressure and temperature just blew it out.
After a lot of messing I just welded it in. I wasnt able to find a better solution.
After I patched it up with the JB Weld I received a message from Bill to braise the cylinder, and had I read that first I probably would have tried that technique.
jkv357 wrote:
Thu Jun 20, 2019 8:53 am
I can't tell where the problem was.

Was it a crack?
There’s a casting error with pores passing through from the water jacket into the exhaust port. The leak can be seen in the photo on the left near mid way of the exhaust port, and then also looking into the water jacket, but it is incredibly difficult to photograph with a cell phone!

At this point in time I didn’t realize that there were also a leak into the cylinder stud hole, but I would learn that soon enough! :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: Another Change in Direction

Post by toratora » Thu Jun 20, 2019 11:39 am

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After sealing up the leak with JB Weld it was time to install the Metrakit ProRace top end—once again. Sadly this would result in the same disappointment, and ultimately the decision made to not use the kit at all! :scream_cat:


Thankfully the heat subsided!


Putting it back together, and prepping for the leak test.




I didn’t see any appreciable leakage, but there was pressure loss, which could possibly be explained by the leak in the pump.


With the rest of the bike put back together it was tested, with the same results. A water wet plug, and wouldn’t run.


A small JB Weld bubble can be seen here. The patch didn’t leak, but as it turns out there appears to be a leak in the cylinder stud hole, which reintroduced water into the combustion chamber. I did check to see if water had gotten into the transmission, and it appeared to be fine.


At this point I completely gave up on this kit. I had an older ProRace kit which was in okay shape. I used the new piston, and installed the old kit. Interestingly the piston o-ring from the new kit doesn’t fit the older kit. This set up started right up—huzzah a running bike! :ghost:

However, I discovered that the clutch cover gasket had dried out, and was leaking. This would need replacement, but that would have to wait. :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 Gasketts

Post by toratora » Thu Jun 20, 2019 1:39 pm


Since the clutch cover gasket dried out, and was leaking I had to replace it. Thankfully I had a new gasket kit laying about!


This isn't a particularly difficult job most of the time, but it is a pain in the ass because you have to drain the coolant, and at least the oil of out the clutch section of the transmission. And placing the cover back on inside the GPR frame can be a bit more difficult since the wiggle room is nearly non-existent. Still it was nice to move past this part of the task.


I upgraded this bike with some clear blinkers from EasyParts, but the quality isn’t so great. They were cool about it and gave me a discount on a future order. There are two problems with these blinkers. First they flop over, and second they fall off the securing bolt. I can’t really do much about the flopping over, but a washer seems to help with keeping the blinker is place. Kind of hack, but will do for now. :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: Return of the Skirts

Post by toratora » Thu Jun 20, 2019 5:39 pm

Image
The ProRace bike with skirts!! :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: Electron Transfer

Post by toratora » Fri Jun 21, 2019 9:39 pm

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I’ve had so much difficulty with batteries on these bikes where pretty much nothing seems to survive. The Shorais failed miserably, the Ballistics were failures too even if they were okay for a very short time, and even the Neptunes proved to be a waste of money.

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Yuasa Yumicron YB4L-B
The stock battery is a Yuasa Yumicron YB4L-B which features 4Ah at 2.8lbs. The dimensions of the stock battery are 120mm x 70mm x 92mm. These are decent batteries, and probably the best way to go, but I’d like to find something that is a step up.

The most current GPRs came with a Yuasa YTX5L-BS, which is probably what I should have bought, but these bikes employ a 4 sized battery so I ordered the YTX4L-BS. The YTX4 and 5 are nearly the same dimensions. The 4 comes in at 114mm x 71mm x 86mm, with the 5 being 2cm taller. The 4 is a 3Ah battery where as the 5 is rated at 4Ah. The 4 weighs in at 3.4lbs, and the 5 at 4.2lbs.

The advantages of the YTX is that they are maintenance free, spill proof, and supposedly hold their specific gravity three times longer than the standard Yumichron. It will be interesting to see if the Ducati ignition in the GPRs can keep the YTX charged.

The setup process is a bit involved so I took a bunch of photos. :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: Shake Down Ride

Post by toratora » Sat Jun 22, 2019 9:39 pm

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The various bikes have been getting their shake down rides, and all of them have proven to need a little something, and the ProRace was no exception.


First up was installing the YTX. This went well enough, but then I discovered that the MyCron wouldn’t turn on. The blinkers, tail light, and horn were working properly so I went and retrieved the multi-meter.

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I found that there was only 2.5 volts being sent to the MyCron, when there was supposed to be 7.5. I also found that the DC to DC converter was way hotter than normal, even when not connected to anything but the battery. So I disconnected it, and ordered a new one from Amazon.


I was hoping to have a tach to watch for this ride, but that was not to be. First stop on the ride was Kent’s Moto Garage.


Then a quick visit to Ocean bikes, and the Target for supplies. The bike is very peaky. No power to probably around 10K, and lots of vibration to go along with it. But when on the pipe it goes pretty well. The new convertor should be here on Monday, and then I’ll find out where the R’s are... :paw_prints:
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