Trident Troubles and a Hot Firebird

Troubles with Trident motorcycles, a Firebird thats hot to the touch, and tires for a Honda restoration.

By Staff
article image
by Flickr/Neil Randell

Honda tires

Q: I have owned my Honda CB450 since 1970. I have just started working to restore it. This model was the first 5-speed 450 made, and it came out with a 3.25 x 18-inch ribbed front tire. I’m not having any luck finding this size tire on the internet. Do you have any resources that I can contact?

Steve French/via email

A: If you’re set on having the classic tread pattern, try Sirius Consolidated Inc. ( They sell Liberty tires in classic patterns. If modern tread patterns are OK, Michelin makes a Road Classic line that has a tire in that size. You’ll have to ask for 100/90-18 as they don’t size by inch anymore.

Trident troubles

Q: Hello, I am working on a 1974 Triumph Trident. When I received the bike it did not have an auto advance or plate installed so I bought the parts. When I was going to install the auto advance I noticed there is no notch or pin for the auto advance to install to. It’s just a conical shape that has a center bolt as I’m sure you know. It does have a notch on the conical shape of the auto advance piece, but nothing inside the hole of the engine to line it up to. I’m curious how to install the auto advance to make sure it’s in the correct position.

Mark/via email

A: I was going to try to explain this here, but quickly realized it would be a whole column in itself. Instead, I found an online version of the Trident service manual from Classic British Spares ( Scroll down to Triumph and BSA A75 T150 and T160 triples and the information you need is found starting at Page 79. It’s more complicated than the twins, but if you follow the instructions you will have success.

Another Trident question

Q: Keith, I’m not sure if this question warrants publication, but your advice may save me a lot of time. About 25 years ago I purchased a 1974 T150 and drove it regularly during the summer months for 10 years straight with regular maintenance. My trips were always short, never any long rides and I probably put 10,000 miles on it. The clutch was new when I purchased the bike. After that time I would ride it very sporadically for the next 10 years letting it sit for a year or two not starting it but keeping it properly stored. I took it on a 60 mile trip about 5 years ago and the clutch began to slip, mostly in the higher gears. I adjusted the clutch and couldn’t get rid of the slipping so I havn’t driven it since. The clutch probably has maybe 12,000 miles on it. I was talking Triumphs with a few guys at the Mid-Ohio show this year and brought up the problem with my Trident. I’m betting it needs a new clutch but one of the guys in the group told me that before tearing into it, try spraying brake cleaner through a pipet into a little hole beneath the clutch, underneath the engine to attempt to clean out any debris. I’ve never heard of this and cannot recall seeing a small hole underneath. What would this be for? I’m reluctant to try this. I’ve never had the case off and I don’t actually know what the brake cleaner would be hitting when sprayed into the hole. Do you have any advice to offer before I get into putting in a new clutch?

Mike Perozzi/via email

A: There is a hole underneath the clutch housing. It is meant to drain any fluid that might find its way into what should be a dry cavity. I imagine the purpose of spraying brake cleaner in there might be to try to clear any oil contamination off of the clutch plate, but I can’t see it being very effective. The only way to get the solvent to the clutch plate surfaces would be to engage the clutch while the engine was running, and that gets into dangerous territory pretty fast. It also doesn’t cure the root cause of the oil contamination, so it seems like a temporary solution. I’d go with a complete checkup of the cable and adjustments, making sure there is no pre-load on the clutch pull rod that would cause slipping. You can reference the service manual mentioned earlier from Classic British Spares to find the specifications if you don’t have a service manual handy.

Hot to the touch

Q: Hi Keith, I have an issue I hope you can help me with. I recently restored a 1968 BSA Firebird Scrambler with a full engine rebuild. The pistons are +40, with 9:1 compression and stock points. I only have 50 miles on the break-in so far using 10w40 oil. My problem is that after I shut down the engine, the carbs become so hot that I can’t touch the ticklers and the gas seems to be boiling in the float bowls. The timing is spot on and the oil seems to be circulating well. The bike starts first kick and runs well. Any thoughts? I love your column, great magazine!

Peter Reitel/Bedford, Quebec, Canada

A: It sure sounds to me like the insulating washers between the head and the carburetors are missing. There should be a thin paper washer at the head, then a thicker insulating washer, and finally an O-ring between the insulating washer and the carburetor. If the insulating washer is missing, enough heat is transferred to the carbs to cause the problem you mention.

Email questions and feedback to or write: Keith’s Garage, Motorcycle Classics, 1503 SW 42nd St., Topeka, KS 66609

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