Cafe Racer Forum banner

1978 Triumph Bonneville project

12K views 71 replies 11 participants last post by  steveo 
#1 ·
Quite looking forward to this one.
 

Attachments

See less See more
1
  • Like
Reactions: TrialsRider
#6 ·
Yes mate, it is the dealers bike. It looks half decent in the pic, but not so much up close.
First job will be sorting out some wiring, and see if it'll run.
The owner wants the frame painted, tank resprayed in an original colour, silencers, rear wheel rim , and wiring loom will probably need replacing.
Not to mention all the usual service items.
So a fair ammount of work
 
#7 ·
A good few hours spent in the shed today.
After making a rather large bodge with the wiring, all the electrics seem ok, with the exception of the brake light. Even had a spark.
I was just about to give up getting the bloody thing started when it finally fired. It's idling at 3000rpm, but it's a start.
The sump drain plug is going to be a issue, it's been way over tightened, and I've managed to round it off. Tried heat, and hitting it with a chisel, but it won't move.
No real suprise that there's an oil leak or two.
 

Attachments

#10 ·
Is that the factory plug in there? Hard to tell from the photo, but it looks different. ... mine is the first incarnation of the OIF (wish I had a better acronym... something about oil and the floor) , so the plug may have changed by 78. I can use either a 1/2 BSW or 13/16 “normal” socket. Yours looks smaller, with a flange on it. Maybe they reduced the size in a failed attempt to keep folks from reefing the shit out of it. I would be inclined to warn the owner just in case someone jammed something foreign in there and things are going to go south.
 
#12 ·
Sorry about the crap pic it was as good as I could get from underneath the bike.
Can't say for sure if it's the original plug, but it is 13/16ths. My main worry is hitting to hard, and crackiing the case.
The young man who has made me a number of alloy tanks over the years is good at this sort of stuff, so may well give him a call tomorrow.
 
#13 ·
Screw Tool Auto part Cutting tool Screw extractor


Does he have a TIG welder? I did this one a while ago.... it was in something important, so was sweating bullets setting it up, so the drill would be centred and not take out any threads. Works well for small stuff, but with the flange on the drain plug it takes more than these guys to budge it. If he bevels the end of whatever he welds on there, then you can sneak in there and get reasonably good penetration on the backside. Don’t think I would want to use anything other than TIG. Easier to control things and actually see what’s going on. Either way good luck... it is gratifying when the little bastards come out without any drama.
If you lived closer, I could fix you up with a NOS rim, but the catch is it’s amongst a bunch (all unlabelled) and you might go mental figuring out which ones are drilled for conical hubs.
 
#14 · (Edited)
View attachment 98441

Does he have a TIG welder? I did this one a while ago.... it was in something important, so was sweating bullets setting it up, so the drill would be centred and not take out any threads. Works well for small stuff, but with the flange on the drain plug it takes more than these guys to budge it. If he bevels the end of whatever he welds on there, then you can sneak in there and get reasonably good penetration on the backside. Don’t think I would want to use anything other than TIG. Easier to control things and actually see what’s going on. Either way good luck... it is gratifying when the little bastards come out without any drama.
If you lived closer, I could fix you up with a NOS rim, but the catch is it’s amongst a bunch (all unlabelled) and you might go mental figuring out which ones are drilled for conical hubs.
He has a TIG welder, only problem is I'll need to get the engine over to Brightlingsea, which is a bit of a faff.
Not sure what the previous owner was thinking regarding the wheels. Both have stainless spokes fitted, the front rim has been replaced with a newish Hagon, the rear rim however looks to be original, and is as rough as a Badgers arse.
 
#19 ·
I've been using a large wrench on the head of the bolt in an attempt to free it.
Looking at the overall condition of the bike I'd say it's been ridden through a good few winters. Every nut, and bolt seems to be putting up a bit of a fight.
Just out of interest I checked the MOT history. Turns out to be a 1977 model, original colour was blue. Last MOT was 12 years ago, and since 2006 has covered the grand total of 5 miles.
Looks as though the mileage of 11922 miles is probably genuine.
 
#20 ·
I'll give it another go when or if the engine ever comes out.
About 10 years ago I had a similar issue with a front engine mounting bolt on a R100. Ended up having to cut through the bolt, and take the engine to an engineer to drill it out.
Riding through UK winters doesn't do a bike any favours.
 
#21 · (Edited)
I recently had the opportunity to use a friend’s induction heater to remove the spark plugs from the engine in my brother’s Dodge van. He had not changed them in over 90,000 miles of use. I removed the easiest of them to access (with the doghouse removed) and it was TIGHT!!! Assuming that penetrating oil wouldn’t get past the plug gasket (and reluctant to further tempt fate), I borrowed the heater and alternated applying heat to the nut of each remaining spark plug and dousing it with a soybean-based penetrating oil my friend also swears by. It worked like a charm. None broke. Though pricey, the induction heater was safer than an oxyacetylene torch and allowed the heat to be applied to the spark plug, only. If I still did this kind of stuff every day, I would definitely own one.
 
#22 ·
interesting. never thought of one of them.

maybe heat the swingarm pivot pin with a torch, so it conveys the heat down, then fill the recess with penetrant, etc and let it go cold. i recall the old american v8 oil gallery plug trick of heating the plug with a torch until red, then putting a candle on the end of it and letting the wax melt in. then allegedly you could just screw them out.
 
#27 ·
Winter riding here would require studs. They use a liquid brine as well as salt on the roads in the winter to melt ice. I have found if you ride before the rain has had a chance to wash it away in the spring you have a film of the powdery leftovers on the bike. Left on it just eats things.

When I go from winter (steel wheels) to summer tires (alloy) in the spring the wheels are quite often rust welded on. I've gotten so I sandblast and paint the inside of the winter wheels, every summer, where the contact with the hub is made. Brake calipers have become a r&r item the brine eats them so badly. Freeing up rusted motorized shit has become a common spring topic here.
 
#30 · (Edited)
I hate that salt brine so bad.. why cant people get studded tires and learn to drive instead.. southern swedens roads are thick with it all winter, up north it freezes so deep that salt is useless, and their cars last forever..
About that pivot bolt, i would just cut and drill it, get the swing out of the frame and press out all the bushings. If its rusted that stuck youre gonna need new everything anyway.
 
#31 ·
Not much to show for 3 weekends of work.
Still can't get the swinging arm to budge but got a few parts cleaned up/powder coated.
Virtually every nut and bolt has put up a fight so far.
Just a quick question, I've fitted some stainless M6 fixings to the rear mudguard does this mean that I'll burn in hell?
 

Attachments

#36 ·
Take a good look at the area around the swingarm and down tube. If that one was cracked badly you’d know it by now. If I understand correctly, it was the early ones that were more likely to have the problem. Anyway.... better to look now just to make sure.

https://www.triumphrat.net/classic-vintage-and-veteran/635474-t140d-frame-oil-leak.html



Have you been soaking the swingarm pivot bits? I should really take my own advice and go see if I can pull my swingarm spindle without any drama.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top