Upgrades - Diablo 500 (1967) to 502/3 (1968-69)

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Re: Upgrades - Diablo 500 (1967) to 502/3 (1968-69)

Post by Go Go Diablo » Mon May 14, 2012 7:37 pm

Bogie Stations -Continued

The suspension arms and all stations are made of 12 Gauge Steel and welded to tubes in a different form to prevent welds from cracking. Rubber springs on side and front bogie stations have been relocated whereas the rear station remains in its original position. In order to reduce wear, all bogie stations are mounted to the frame on large diameter pivot housings which accommodates a reinforced rubber bushing. The pivot pin is held in position by a cotter pin instead of a spring washer. A bogie station limit travel pin has been welded to pivot housing.

Bogie wheel tire will be concentric with center and all shafts will have free and easy rotation in bearings.


The 500 bogie is on the left and the 502/3 on the right. Note how much heavier and wider it is.
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A picture of the spring washers on the 500 which were replaced with the welded washers.
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A picture of the brass bushing in the 500 which were replaced with rubber bushings.
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Like Mike says, all in all, a much better suspension and bogie design in 1968 & 69.
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Re: Upgrades - Diablo 500 (1967) to 502/3 (1968-69)

Post by Go Go Diablo » Sun May 20, 2012 8:48 am

Track Belts

Material used for track belting and grousers will remain unchanged. The rivets and washers have been increased in size (Rivets 9/16" in length, Washer 9/16" in diameter). To eliminate damage caused by the track belts coming off while in motion, track guide rods have been bolted to the inside and outside making it almost impossible to throw a track which has the recommended adjustments.


Track lengths vary and I've always wondered if the original tracks for the 500 were slightly shorter than those made later. An ideal track length measured from rubber to rubber is about 105-1/2" to 106". I have seen some of the original tracks with the smaller rivet washers measure as short as 105". However, I believe the rubber belting is susceptible to growing and shrinking.

Sorry, I don't have any good pictures of the track guide rods. These are the rods bolted on the rear of the chassis between the tubular tunnel and the outward side plates of the chassis.
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Re: Upgrades - Diablo 500 (1967) to 502/3 (1968-69)

Post by Go Go Diablo » Fri Jun 01, 2012 7:57 pm

Handlebars

Material has been changed to 14 gauge from 16 gauge. Upright connections from deck are made with cupped ends in order to allow a stronger weld. For additional strength, tube braces have been added along with triangular braces. Extra support plates are welded to handle bar to attach ignition and light switches. The dash strip is now a continuous welded strip on the handlebar with a rubber grommet and steel insert to accommodate hood lock pin.


500 handlebars on the left and 502 handlebars on the right. Many of the 500 handlebars have been bent as they are fairly light in construction. Bolens offered a reinforcement kit to add gussets behind the dash to add support. Later model 500's had the gussets installed at the factory and they protruded out through the dash back toward the handles.
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The 503 handlebars are shown below.
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Re: Upgrades - Diablo 500 (1967) to 502/3 (1968-69)

Post by Go Go Diablo » Wed Jun 20, 2012 7:41 pm

Dash Panel

All new design with sharp edges and protruding flanges eliminated. A new material, Cycolac "L", is being used and thickness of material is increased almost 60 percent from last year. This new material is guaranteed to resist low temperatures.


Below is a picture from our friend Barrie who shared the three dash designs of the Diablo. The one on the bottom is the original Diablo 500 dash. As mentioned earlier, a later model 500 dash had slots cuts for handlebar gussets and this one is in the middle. The dash at the top is the 502/503 dash.
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This is a photo of Jake's Diablo 503 with a very nice dash on it.
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Re: Upgrades - Diablo 500 (1967) to 502/3 (1968-69)

Post by Go Go Diablo » Wed Jun 27, 2012 8:01 pm

Bumper Assembly

An aluminum bumper is being used with additional diagonal braces. Bumper brackets are secured to the reinforced portion of the deck frame assembly.


If you have an early version of the 500, you would have only two bumper brackets. Later model 500's added the diagonal brackets mentioned above. However even with the additional brackets, the chassis was not solid. So where the bumper brackets mount, Bolens added a rolled angle iron reinforcement to the chassis.
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What is not mentioned is the chrome bumper from the 500 was continued with the production of the Diablo 503. My guess was Bolens decided to pretty up the 503 model.
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Re: Upgrades - Diablo 500 (1967) to 502/3 (1968-69)

Post by Go Go Diablo » Sat Jul 07, 2012 1:29 pm

Gas Tank and Line

Pre-assembly inspection will insure clean and leakproof gas tank. The tank is mounted on a rubber pad fastened to the deck with pop rivets. Gas tank caps have lugs to make it easier to remove in the field. A fuel filter was added in the gas line and the line is secured away from the heat of the engine.


An interesting comment about insuring the tank will be clean and leakproof...... Makes me wonder if the original batch of tanks were not clean and leakproof. :D

Original Diablo 500 gas tanks had brackets on the side so the dash could be mounted to it. Later, I presume some of these tanks were put on the 502/3 until the inventory ran out, then tanks were installed without these brackets. Some tanks have the barbed fitting coming out the back corner of the tank toward the engine and some have the barbed fitting coming out the side. Not sure what was up with that.

Original Diablo 500 gas caps were chrome with no lugs. They were difficult to get off at times. The lugs were an improvement.

Below is a picture of a tank in a 502 chassis. Note it has the brackets mentioned above.
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Re: Upgrades - Diablo 500 (1967) to 502/3 (1968-69)

Post by Go Go Diablo » Sat Jul 28, 2012 10:07 pm

Controls

Model #502 - Manual Starter will remain identical as last year. The throttle on the left-hand side and the brake on the right-hand side.

Model #503 - Electric Start has a thumb throttle control positioned on the left-hand side of the handlebar. The brake control remains in the same position on the right-hand side.


Here is a picture on the 503 handlebar levers.
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I've yet to find a reasonable explanation why the 503 has a thumb throttle. Whether it is the half moon handle or the thumb throttle makes no difference in how the cable controls the lever on the carb. I suspect some crafty engineer said "Lets make this Diablo a little different than the others" and make the upgrade happen. The idea of the thumb throttle is nice at times, but holding it down can give you some thumb fatigue.
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Re: Upgrades - Diablo 500 (1967) to 502/3 (1968-69)

Post by Go Go Diablo » Mon Aug 20, 2012 8:15 pm

Engine and Carburetor Assembly

Model #502 - Manual Starter is the Hirth 054, 300 cc with Tillotson carburetor mounted in a new position to prevent any form of tension on the new, improved shearmounts. This new position reduces engine deflection, due to shock of loading when jumping the machine.

To eliminate vapor lock caused by hot air, a shield has been installed between the carburetor and engine to control air flow.


The comment about the Hirth 054 is interesting. Most Hirth motor tags you see will state something like 54R1, 54R2 and so on. The "R" designation refers to the orientation of the head or the size and shape of the PTO shaft. However, all Diablo 54R motors do not have this "R" designation. I believe that is because the 54R used in the Diablo is a special motor from Hirth and the main difference is the small tapered PTO Shaft and the size of the engine seals. Finding a seal and gasket kit for these motor is virtually impossible which is why I assemble my own kits for you.
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I also like the comment about "jumping the machine". That sounds fun, but my guess is you would only do it once. :D
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Re: Upgrades - Diablo 500 (1967) to 502/3 (1968-69)

Post by Go Go Diablo » Fri Oct 26, 2012 9:06 pm

Engine and Carburetor Assembly

Model #503 - Electric Starter is a Hirth Model 019 engine with a Tillotson carburetor mounted in the same position as Model #502. A Heat Shield is also installed on this model to eliminate all possibilities of vapor lock.


As we know, the Electric Start motor in the Diablo is a Hirth 190R. With that, the statement above can be a little confusing. The starter is a Bosch starter with direct mounted solenoid.
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Re: Upgrades - Diablo 500 (1967) to 502/3 (1968-69)

Post by Go Go Diablo » Fri Nov 09, 2012 10:31 pm

Hood Assembly

The hood has been redesigned with series of supporting braces added at strategic points for reinforcements and to positively hold contour of hood. A 14 gauge strip has been added at the rear of hood and the ends are turned over. Supporting angle brace is used for hood opening instead of slots in hood.

The hood is firmly held down in position by having the pin located through a rubber grommet and steel insert in the dash reinforcement strip.

To allow for correct air flow in the engine compartment, a series of louvers have been added on the hood.

The hood support assembly has been reinforced with triangular braces in order to support the hood correctly in both the open and closed position.


There is no doubt the hood is a much better design!
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