Moto Guzzi National Owners Club
Moto Guzzi National Owners Club
Moto Guzzi National Owners Club
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Tips for Guzzis - 2003/10

Restoring Faded Plastic Taillight Lenses on Ambassadors and Eldorados

After a few years sitting in the sun, taillight lenses fade to a shade of pale pink. In this tip, John Prusnek tells how to restore the original ruby luster:

Having restored a 1971 Ambassador recently, I wasn't happy with the condition of the taillight lens. It had stress cracks from vibration and over torquing, and since it had faded to nearly clear, the previous owner had "fixed" it by spraying the inside with red paint. This cut down on the amount of light that could pass through it, resulting in a very dim taillight. Stripping the paint without dissolving the lens was the first order of business.

Having a wife who is a chemist (and whose bike this is anyway) came in very handy with regards to stripping the paint. Suzanne says that the lens is made of polystyrene plastic and things that normally strip paint (like toluene, xylene (xylol), or lacquer thinner will also attack the plastic. If the label says aromatic hydrocarbons, don't use it.

Things that will work are ketones such as acetone, and MEK (Methyl ethyl ketone), and, ethanol (vodka). Rubbing or wood alcohol works well also. An equal mixture of acetone, MEK, and alcohol works best.

The next part requires a trip to a craft store for a small (1 oz will do ya) bottle of transparent glass paint, the type used to make fake stained glass ornaments. The stuff I used is called Gallery Glass #15118 Ruby Red. I'm sure there are other brands. Follow the directions on the bottle (not rocket science) and you'll be fine. It has the consistency of molasses. You should coat the inside of the lens in quadrants, propping it up on a rag to keep the part you're working on flat. Let it dry for a day or two and do another quadrant. Fill the lines and textures molded into the inside of the lens to just about their highest points, the point being that the coating has an even thickness. Be patient, do several coats... it's a two hour job that takes a few days. An added benefit to this process is that it strengthens the lens if it's cracked. For a final touch polish the outside with a plastic polish such as Maguiars, or if you know what you're doing use rouge and a string buffing wheel. Don't forget that there's a rubber gasket in there, and use a dab of Loctite instead of muscle if you're worried about it coming off. Now get out on the road and let your little light shine.

Right Side Grip Vibrate More than the Left?

In this tip, John Ulrich describes an easy fix for excess vibration in the right grip:

Try moving the master cylinder/mirror assembly forward! Simple and it worked for me. Be sure you can still "grab-a-handful" of brake lever if the need arises!

The #714 style of Pro-Gel grips has a deep dimpled surface that resembles a golf ball, this also helps.

Are Longer Shocks Really a Good Idea?

In this tip, John Chicoine describes his experience with longer shocks on his Eldorado:

In an earlier MGNOC newsletter you ran a piece by a gentleman who was expounding upon the merits of longer-than-stock shocks on his Eldorado.

I once installed shocks that I ordered from a company only to have my universal joint fail after less than 10,000 miles. Upon investigation I discovered that the shocks were not correct. They were 1" longer than the stock shocks. After installing shocks of the proper length and a new U-joint I had no more problems. The same U-joint is still in the bike after more than 25,000 miles.

I believe that the premature failure was due to the swing arm being constantly on a slight angle rather than parallel with the axis of the transmission output shaft.

For what it's worth, I run longer Koni shocks off of a LeMans 1000 on my Eldo. I love the extra ground clearance. I just examined the u-joint after nearly 80,000 miles, and it was fine. That said, I've gone through two carrier bearings in that time, so maybe that's what takes the extra stress on my bike. Also, at 240 pounds, maybe my shocks are sacking back to the stock height when I sit my lardy butt on it.

Bleeding Guzzi Brakes

In this tip, Joe Olde, tells of a gadget that did the job for him when bleeding his LeMans brakes:

I should have known better, but after three hours of trying to bleed the brakes on my LeMans V, I gave up. Tried method of reverse filling the system, which did not work. A searched of the net reminded me of the old Dot 3 method. Baby bottle, with line in fluid, pump the brakes to purge the system, farthest first, hold above master cylinder. In short I went to Auto Zone and for $6.99 plus tax got the perfect tool. One Man Brake bleeder. Started at the front, did rear, finished off with the proportioning valve, ten minutes, done.

Alternative Sources for Shifter Linkage Rod Ends

In this tip, Matt Kesti tells of a cheaper source for the rod ends used in Guzzi shifter linkages:

I have a '98 Centauro GT. It has the GT foot control set up, which includes lowered foot pegs. These lowered pegs mean that the shift and brake lever are longer than the standard Centauro. I have broken the shift linkage on two different occasions to the transmission. This shift linkage includes two ball joint rod ends, with a threaded connection piece between the two. One rod end connects to the transmission arm through a hole with a nut on it. This is a correct application of this rod end. The other rod end threads into the shift lever, with the shift lever being the nut. This is an incorrect application and puts stress on the threads, which are tiny 6 mm, and this causes the rod end to break off in the shift lever. This is a problem on the road because it requires the broken piece to be drilled out and an easy-out to remove.

These rod ends are over $50 from the friendly Guzzi dealer. I have found the exact, (and I mean exact), rod end from a local industrial supply house "McMaster-Carr". It is found under "ball joint rod ends" under the title "boot protected metric ball joint rod ends", part number 6275K11 for $8.25.

These rod ends are used on all Moto Guzzis. I've looked on other Guzzis to see if there was a larger rod end, but this is not the case. I can buy an 8 mm rod end from McMaster-Carr, but there is not enough room on the bike for this. At least I can replace them before any major road trip and carry spares at $8.25 not $50.

Check the Oil-Pressure Relief Valve on Spine Frames

New Mexico Rep Kevin Hamann describes a disturbing incident with a Centauro:

There was a guy named Mark in Albuquerque who had a maroon and silver Centauro he'd bought new 4-5 years ago. Never met him, but saw him at the Cedar Crest Chevron station once. I heard from some of the local "geriatric road racers" that it "blew up" after the oil pressure light came on while riding. So I called Steve Spreeter at Renaissance Motorcycles in Tucson where it was purchased and he said the oil pressure relief valve (OPRV) hadn't been torqued down properly (screws into the bottom of the oil pan) and the engine had lost oil pressure. Steve replaced the scorched rod bearings and perhaps rocker arm bushings and had the bike back for sale under warranty. Mark got another bike. So if your Centauro's got an oil light coming on it might be worth it to drop the pan and check the 19 mm OPRV fitting.

[Ed Note: Long story, so Ill get to the point. In 1981 I rode my '77 T3FB from Kansas to central Ohio. It was early August and very hot, and took I-70 to get there. In other words I wasn't going slow. The idiot lights on those models were so dim you couldn't see them in the daylight. At some point I noticed the oil light was on. I assumed the oil sensor had died (common thing in those days), and I also assumed if the T3 had no oil pressure it would have died long before for sure. The deal is there was no relief valve under the pan. It was gone entirely. The dealer in Ohio reckoned the T3 had maybe 5-8 pounds of oil pressure (at speed) - tops. Again - it was hot and I was going fast. Later, the only sign of damage (I could tell) was the rocker arms looked like maybe they had gotten a little hot. I kept that Guzzi for another 11-12 years, and I never replaced anything due to only running on 8 pounds of oil pressure. Guzzis are tough! -FW]

Better Tires for V11 Sport

In this tip, Mike Bowling tells how a change of tires cured some of his Sport's handling ills:

I own a 2000 V-11 Sport and have experienced the quirky/nervous handling that appears common to these bikes. It was not enough of an issue with me to try to work it out of the bike. The bike was due for tires at 4700 miles and instead of going with the OEM Bridgestone BT-56 I installed Metzler MeZ-4. These had a very calming effect on the bike. I believe if the bike would have had these tires as stock I would not have noticed any problems.

Bosch Regulator and Generator for Loop Frames

North Florida Rep Jim DeGregoria tells of a cheap replacement for the Bosch regulator used on generator systems, and for parts for the generator:

From the TIPS I BOOK, pages 53 and 138 Eldorado voltage regulator replacements are not procure-able any longer but you can get the replacements at the following store at a substantial dollar savings over the dealer prices.

Discount Auto Parts Stores has a replacement which looks like a BOSCH regulator. Cost is $24.99 plus tax Their part number is VR635. It works as and is designed for all VW Bosch systems with an output of 35 plus watts. The same as in the Eldorado book. Also the generator brushes and entire generator is on the shelf for $48 plus tax . This item is applicable to the square back VW's of that era.