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Technical Q and A for classic motorcycle maintenance and repair.


Triumph Bonneville Silver Jubilee Questions

Motorcycle Classics tech expert Keith Fellenstein
Editor’s note: If you’re having trouble with that old Suzuki, BSA or BMW, Keith Fellenstein is your guy. From motorcycle tuning tips to detailed motorcycle engine repair, he can draw from a wealth of experience to help guide you to success. Send questions to: Keith’s Garage, Motorcycle Classics, 1503 SW 42nd St., Topeka, KS 66609, or send an e-mail with “Keith’s Garage” as the subject.

Triumph wiring

Q: I recently acquired a 1977 Triumph Bonneville Silver Jubilee. The engine number does not match the bike. I was able to contact the owner and he told me the engine was replaced by the Triumph dealer under warranty after only 200 miles because of a poor engine case casting causing oil to leak in on the points. Have you ever come across this? The dealer, Free State Cycle in Bladensburg, Maryland, is no longer in business, so I can’t contact them for confirmation. Any help would be appreciated. The bike has been sitting for a number of years and it is going to take some work to get it back on the road. I enjoy the challenge. There is nothing more satisfying than hearing a long dead engine fire up. Also, do you know when Triumph went negative ground?

Chuck/via email

A: At one time, dealers had access to unstamped cases for situations like this, but by 1977, with all the troubles Triumph was having, maybe they weren’t available anymore, or it was just easier and less expensive to do an engine swap. Today, we prize matching numbers, but you have to remember that at the time these were just motorcycles; no one was thinking they would be collectible someday. About the only thing you can do is just ride it and enjoy it. Sorry I can’t be more helpful. As to your second question, it looks like 1979 was the first year for negative ground. Triumph changed the shape of the regulator and they note in the parts list that it is negative ground and not interchangeable with earlier regulators. And I agree: Hearing one of these old beasts come back to life is inspiring. When I work on one for someone else, the look on their face when they hear it start up for the first time is priceless.

Email questions to keithsgarage@motorcycleclassics.com

BSA Spitfire Hornet Oil Pressure Gauge

Keith Fellenstein width=
Editor's note: If you're having trouble with that old Suzuki, BSA, or BMW, Keith Fellenstein is your guy. From motorcycle tuning tipe to detailed motorcycle repair, he can draw from a wealth of experience to help guide you to success. Send questions to: Keith's Garage, Motorcycle Classics, 1503 SW 42nd St., Topeka, KS 66609, or send an email with "Keith's Garage" as the subject.

Q: I have a 1966 BSA Spitfire Hornet (A65) and I want to install an oil pressure gauge. How is that best accomplished and where do I tap into the engine?
— John Damon/via email

A: From my limited knowledge and research, it's not feasible to fit a pressure gauge on earlier A65 cases. You can fit one using an old oil pressure relief body for testing purposes, but you then give up the pressure relief aspect of the valve, so you really can't use it daily.

Triumph Bonneville T140V Hard to Start

Keith Fellenstein Tech Corner
Editor's note: If you're having trouble with that old Suzuki, BSA, or BMW, Keith Fellenstein is your guy. From motorcycle tuning tips to detailed motorcycle engine repair, he can draw from a wealth of experience to help guide you to success. Send questions to: Keith's Garage, Motorcycle Classics, 1503 SW 42nd St., Topeka, KS 66609, or send an e-mail with "Keith's Garage" as the subject.

Q: I am the original owner of a 1978 Triumph Bonneville T140V. For the first four years of its life, it was the focus of most of my attention and I put 44,000 miles on it. Then life came along and the bike sat in the garage for more than 20 years. In 2011 I was given some parts for Christmas and the journey back to life for it began. Since then I have had the engine completely rebuilt, the carburetors thoroughly cleaned and have done tons of other maintenance so now, even after sitting (battery on tender), it starts with usually less than three kicks from cold. My problem is it will not idle when cold, and when hot will idle at a high 1,500rpm, but will die off at an intersection if I do not blip it occasionally. I have the original carbs, but found one to have an oval slide barrel, which I had fixed. I also tried to use another set of carbs but still have the problem. Can you offer some advice?
— Karl Stram/via email

A: I always advise people to not tune their bikes so they idle well cold. They don't stay cold long, and then they're running rich when they reach operating temperature. As for your high idle when hot, a few things can cause this. An air leak leaning out the mixture is one. Another, fairly common issue is a sticking auto advance unit, assuming you are still running points. I'd start by gapping the points and making sure the timing is correct, and confirming that the auto advance is lubed and working. After that, I'd look for air leaks around the carburetors, which you can test by spraying around the carb mounts with water. If the idle changes, you have a leak. In an effort to stop people from distorting the carburetor by over-tightening the mounting bolts, Triumph had moved to cupped washers with O-rings (they called them insulators) under them. If those are missing or flat, there is a good chance for an air leak around the O-ring that seals the carburetor to the manifold.

Triumph Trident Electrical Problems

Keith Fellenstein Tech Corner
Editor's note: If you're having trouble with that old Suzuki, BSA, or BMW, Keith Fellenstein is your guy. From motorcycle tuning tips to detailed motorcycle engine repair, he can draw from a wealth of experience to help guide you to success. Send questions to: Keith's Garage, Motorcycle Classics, 1503 SW 42nd St., Topeka, KS 66609, or send an email with "Keith's Garage" as the subject.

Q: My 1974 Triumph Trident continues to blow the 20-amp fuse located near the battery every time I attempt to kickstart the bike. I have also noticed that the directional lights and brake light don't work. The headlight is working, but I can't switch from low to high beam. Any advice on where one should look for problems?
— Tony Zullo/via email

A: Since it's blowing the fuse when you kickstart it, I'm suspicious that either the rectifier is bad, or the alternator is wired to the rectifier incorrectly. Lift the seat and look for the black multi-plate rectifier. The leads from the alternator should be connected to the left and right connectors. On my 1974 Trident, that's green with yellow stripe on the left, and white with green stripe on the right. Brown/blue is in between, and red is attached to the center top lug. If yours is already like this, then we have to delve further. Disconnect the green/yellow and white/green wires and see if it still blows fuses when kicked. Assuming it doesn't, you then have to test the alternator leads against each other and to ground using a multimeter. There should be small resistance across the alternator leads, and infinite resistance from either of the leads to ground. If that all tests out there is a good chance your regulator is bad. Once you have isolated the fuse blowing problem, you can move on to the indicators and brake. Often the indicator switch is corroded, and they can be tricky to fix. The brake should be easier. For the rear, disconnect the wires leading to the brake switch and jumper the spade connectors with a short piece of wire. If the brake light works now, the switch is bad, which is not uncommon. The front switch gets gummed up by brake fluid leakage, as I just found out when I went out to my '74 to test this answer. Well, that and the rear bulb had vibrated itself to pieces again.

Honda VT1100 Hydraulic Clutch Question

Keith Fellenstein Tech Corner
Editor's note: If you're having trouble with that old Suzuki, BSA or BMW, Keith Fellenstein is your guy. From motorcycle tuning tips to detailed motorcycle engine repair, he can draw from a wealth of experience to help guide you to success. Send questions to: Keith's Garage, Motorcycle Classics, 1503 SW 42nd St., Topeka, KS 66609, or send an e-mail with "Keith's Garage" as the subject.

Q: I have a 1988 Honda VT1100 with a hydraulic clutch. Since I got it last year, the clutch engages as soon as the clutch lever comes off the grip. The previous owner said that's the way it always was. I'm used to my 1972 Honda CB750 cable-operated clutch engaging near the end of release. The VT1100 clutch doesn't drag when fully disengaged. I rebuilt both the master and slave cylinders but nothing changed. I don't have an owner's manual, so I don't know if this is normal. Any feedback would be greatly appreciated.
— Dan/via email

A: Hydraulic clutches sometimes feel odd if you're used to a cable-operated clutch, but what you're describing doesn't sound right. When operating the clutch, does the lever move far before you feel a change in the resistance? As an experiment, while accelerating in 3rd gear on a deserted stretch of road, squeeze the clutch lever and see where it is when the clutch starts slipping. If it doesn't let go until the lever is nearly at the grip, there's more to be done, although you may be at the mercy of the engineers' design of the master cylinder-to-clutch cylinder ratio.

Stuck 1969 BSA Victor Engine

Motorcycle Classics tech expert Keith Fellenstein
Editor's note: If you're having trouble with that old Suzuki, BSA or BMW, Keith Fellenstein is your guy. From motorcycle tuning tips to detailed motorcycle engine repair, he can draw from a wealth of experience to help guide you to success. Send your questions to: Keith's Garage, Motorcycle Classics, 1503 SW 42nd St., Topeka, KS 66609, or send an e-mail with "Keith's Garage as the subject.

Q: My 1969 BSA Victor, bought decades ago and never ridden much (other, better bikes at hand) has been stuck for quite some while. The bike was well stored, the tank is clean, and it ran well when I lost interest in it (it was never an easy starter). How do you think I should proceed in getting the engine turning again? I'm pretty sure I ran some penetrating oil into the combustion chamber many years ago.
— Howard/via email

A: The inexpensive penetrating solvent of choice is a 50/50 mix of ATF and acetone. I'd first pull the left case cover off, and using an appropriate socket and gentle pressure, see if you can't get the engine to rotate a little. If that doesn't work, then pour in enough of the penetrating solvent mix to cover the piston top and let it sit and soak down for a couple of days. Repeat these two steps until you achieve success. You can also try using some mild heat from a heat gun (not a torch!) applied to the cylinder, which might speed the process along, too.

1976 Honda 360T Carburetor Trouble

Motorcycle Classics tech expert Keith Fellenstein

Editor's note: If you're having trouble with that old Suzuki, BSA or BMW, Keith Fellenstein is your guy. From motorcycle tuning tips to detailed motorcycle engine repair, he can draw from a wealth of experience to help guide you to success. Send questions to: Keith's Garage, Motorcycle Classics, 1503 SW 42nd St., Topeka, KS 66609, or send an email with "Keith's Garage" as the subject.

Q: I have a 1976 Honda 360T in very nice original shape with just 13,000 miles on it. I just had the bike tuned up at the local Honda shop (new points and condenser, set the timing, adjusted the timing chain, set the carburetors, new plugs). The carbs were not taken apart and cleaned. Upon getting the bike back it fired right up and idled. Taking it on the road for a good run, however, I noticed it missing on the right cylinder, with a "popping" from the right exhaust. Back home, I took out the plugs. The right side plug was fouled badly with black soot, while the left side was a nice medium brown. I tried a new plug and rode it again, but I got the same result: a fouled plug. Using a "color tune" kit I had gotten from England awhile back I was able to see that the plug color changed with increased rpm, from blue to yellow (hot to cold, hence, the fouling). My question is, what could be causing this? The points are new, as I said. I'm wondering if a clogged jet or other carburetor problem on the right side is the cause.
— Bill/Rhode Island

A: I think you've hit the nail on the head. It sure sounds like carburetor trouble from the symptoms you describe. First, I'd try to drain the right side carb and see if there is any clue there. Then I'd pull the right carburetor and make sure it's set up correctly. Water precipitated out of the gas/alcohol mix we seem to get these days will often pool in the bottom of the carburetor and get sucked into the main jet at wider throttle openings.







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