1967/1969 Bonnie Rebuild Desert Sled Project

Glenn

Bonneville T100
Riding for 63 Years
Local time
Today, 04:17
Joined
Aug 13, 2010
Messages
457
Points
47
Age
79
Location
Gibsonville
First Name
Glenn
My Ride
1979 Triumph Bonneville
My '79 T140 looked almost as bad when I bought it. Parts are easily found through a lot of vendors. Just use a search engine to look for parts vendors. Do yourself a favor and take the bike completely apart. It is easier to work on. Also, get the engine rebuilt. Replace all other parts that are a part of the engine (carb, oil pump, etc.) as well as the brake system. I did none of this and had to go back and do it a short time later. Easier to do it while it is apart. Take a ton of photos as you disassemble it. Looks like you have a lot of surface rust that you can remove. The chrome parts fall in this category. Most of the parts you will be able to clean up or paint and save. Taking it apart and putting it back together will give you an understanding of how your bike functions. For my knowledge's sake that was the best thing I did. It gave me a total understanding of my bike. Have fun.
 

grandpaul

Old Bike Lover
Riding for 52 Years
Staff
Local time
Yesterday, 22:17
Joined
Apr 14, 2006
Messages
3,484
Points
302
Age
64
Location
Leander, Texas
My Ride
2000 Legend 900 Triple, 1969 Bonneville vintage roadracer
I'll throw this in -

Not ALL parts need to be replaced. I've only ever replaced a handful of original oil pumps, out or 40+ overhauls. Also only replaced 3 pairs of carbs for premiers out of at least 60 overhauls, refurbs, etc.

Same goes for connecting rods, cranks, and all manner of parts.

The shop manual includes specifications for allowable wear on ALL parts. In my case, on MY bikes (NOT client builds), if my parts were within 1/2 or less allowable wear, they went back in the bike.

Sleeving Amal carb bodies is still cheaper than buying new Premiers. Of course, in some countries, postage to a rebuilder/machinist can be prohibitive.

Obviously, if you are tearing an engine all the way down to the crank, and you can afford to, go ahead and replace everything that's worn enough to be "questionable". If the clean, undamaged parts measure to the low end of wear spec, it isn't critical. Maybe the only exception is big end shell bearings. I've pulled out some real nice lean ones and replaced them anyway.
 

Sundance

Active Member
Riding for 6 Months
Local time
Yesterday, 23:17
Joined
Aug 2, 2021
Messages
134
Points
27
Age
67
Location
Arlington, VA
First Name
Brian
My Ride
formerly Bultaco Pursang and 2009 BMW K1300S
Rocker arm question. See the photo of one of my rocker arms. The face of the tappet adjuster is banged up so I am intending to replace these. I purchased some adjusters with the mushroom type head. Also see the ball end, mine have the hole in the end. I have been reading about changes made to the rocker arm and the difference between the ball with the oil hole and the ball end without. Is the ball end something I should replace also? If so, since this is a pin I’d appreciate advice on how to the the repair. Thank you.

IMG_2432.jpeg
 

Sundance

Active Member
Riding for 6 Months
Local time
Yesterday, 23:17
Joined
Aug 2, 2021
Messages
134
Points
27
Age
67
Location
Arlington, VA
First Name
Brian
My Ride
formerly Bultaco Pursang and 2009 BMW K1300S
My '79 T140 looked almost as bad when I bought it. Parts are easily found through a lot of vendors. Just use a search engine to look for parts vendors. Do yourself a favor and take the bike completely apart. It is easier to work on. Also, get the engine rebuilt. Replace all other parts that are a part of the engine (carb, oil pump, etc.) as well as the brake system. I did none of this and had to go back and do it a short time later. Easier to do it while it is apart. Take a ton of photos as you disassemble it. Looks like you have a lot of surface rust that you can remove. The chrome parts fall in this category. Most of the parts you will be able to clean up or paint and save. Taking it apart and putting it back together will give you an understanding of how your bike functions. For my knowledge's sake that was the best thing I did. It gave me a total understanding of my bike. Have fun.
Glenn, thanks for your comments and advice. I have the bike, engine and all, completely apart down to the swing arm bushings - and will replace those - getting them out was a tedious job. I do have to get to the wheels and brakes, but am going to take those all apart. Got the photos documenting as much as I can and they have come in handy. I've got my frame parts, and some others, out for powder coating. I thought about attempting to do the paint myself, but live in an apartment so could not find a suitable place to spray. When I took this on, I was thinking like you said, that doing this would give me a total understanding of the bike. I'm replacing all bearings and any worn parts I find. Lot of work but it keeps me intrigued.
 

Sundance

Active Member
Riding for 6 Months
Local time
Yesterday, 23:17
Joined
Aug 2, 2021
Messages
134
Points
27
Age
67
Location
Arlington, VA
First Name
Brian
My Ride
formerly Bultaco Pursang and 2009 BMW K1300S
I'll throw this in -

Not ALL parts need to be replaced. I've only ever replaced a handful of original oil pumps, out or 40+ overhauls. Also only replaced 3 pairs of carbs for premiers out of at least 60 overhauls, refurbs, etc.

Same goes for connecting rods, cranks, and all manner of parts.

The shop manual includes specifications for allowable wear on ALL parts. In my case, on MY bikes (NOT client builds), if my parts were within 1/2 or less allowable wear, they went back in the bike.

Sleeving Amal carb bodies is still cheaper than buying new Premiers. Of course, in some countries, postage to a rebuilder/machinist can be prohibitive.

Obviously, if you are tearing an engine all the way down to the crank, and you can afford to, go ahead and replace everything that's worn enough to be "questionable". If the clean, undamaged parts measure to the low end of wear spec, it isn't critical. Maybe the only exception is big end shell bearings. I've pulled out some real nice lean ones and replaced them anyway.
Thanks again grandpaul. I'm not replacing all parts, but lots. The crank measures good and the rods are fine too. This thing hadn't run for 40 years so there was a lot of corrosion, for example, in the fork sliders and the valving was worn there and the bushings looked like they had been installed improperly. Unfortunately a lot of my fasteners for the engine and frame are worn, very corroded - so I am replacing quite a few of those too. While I haven't got new carb yet, I am planning to as my slides were corroded with holes through them, and there was a lot of corrosion on the bodies. As I go along I find that this machine is a mixture of parts of at least a few bikes.
 

Sundance

Active Member
Riding for 6 Months
Local time
Yesterday, 23:17
Joined
Aug 2, 2021
Messages
134
Points
27
Age
67
Location
Arlington, VA
First Name
Brian
My Ride
formerly Bultaco Pursang and 2009 BMW K1300S
I’ve another ask. I’ve looked at the ball end of the rocker arms and the ball surfaces seem smooth and polished so I don’t believe I need to attempt to replace them. I am curious as to why the adjuster ends are so gouged up and pitted. It would seem to me that they shouldn’t wear in this manner. I’d appreciate any insights as to why these might be in this condition? Thanks.

IMG_2433.jpeg
 

Sundance

Active Member
Riding for 6 Months
Local time
Yesterday, 23:17
Joined
Aug 2, 2021
Messages
134
Points
27
Age
67
Location
Arlington, VA
First Name
Brian
My Ride
formerly Bultaco Pursang and 2009 BMW K1300S
What year are my rocker boxes? So, My engine number is EC 19971 T120R. From my look at the engine year data I believe this means it was built in E “May” of “C” 1969, number 19971. Do I have this correct?

If so, I see that my rocker box assemblies are of the older type with the lubrication hole in the ball end. From my reading (in the tech notes from thebonnevilleshop) it reads, “the drilled hole in the rocker arm to supply oil to the ball end was deleted in favor of a notch at each end of the rocker arm bearing,” and that this happened during the later part of 1968, beginning with engine number DU79965. Have I got this right? If so, it appears that while my engine cases are from 1969, my rocker box assembly is from an earlier time, some time later in 1968 or earlier. My frame on this bike is number DU49062, 1967, so I suppose the rocker boxes could have been from the motor original to the frame. Thanks for any comments/insights. I’m trying to get a full idea of what I’ve got here.

IMG_0883.jpegIMG_0886.jpeg
 

Sundance

Active Member
Riding for 6 Months
Local time
Yesterday, 23:17
Joined
Aug 2, 2021
Messages
134
Points
27
Age
67
Location
Arlington, VA
First Name
Brian
My Ride
formerly Bultaco Pursang and 2009 BMW K1300S
I am planning to purchase some new engine case fasteners as well as engine to frame fasteners. It seems that there is a difference in the fasteners kits I see for engine to frame, like on thebonnevilleshop web site. There is a kit for up to 1968 engine to frame, then a kit that is 1969/1970. So my frame is a 1967 and the engine is 1969. Have any of you had this issue before? I’m trying to determine what might be the best kit/solution for my 1969 engine going into my 1967 frame? Thanks again.
 

grandpaul

Old Bike Lover
Riding for 52 Years
Staff
Local time
Yesterday, 22:17
Joined
Apr 14, 2006
Messages
3,484
Points
302
Age
64
Location
Leander, Texas
My Ride
2000 Legend 900 Triple, 1969 Bonneville vintage roadracer
Only issue you will find is in the rare few instances of a threaded boss on either the engine or the frame, in which case you'll have to match that item's year thread form.
 
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