Hi! Been riding since 1970. Owned to Triumphs back in the 70's. A 1965 TR6 and a 1959 T120. After that rode Harleys until a year ago (arthritis, back surgery, etc) when I had to give up riding long distances. Wanted a British project bike to restore. Found a 1971 Thunderbolt locally. Bike was running and I rode it. Engine really strong and shifted well. So paid $3000 for it. I knew it had a lot of work to restore, but...the guy was restoring a 1968 BSA basket case and needed $3000, so...I understand that...bike really worth $2500 max....but...I have restored bikes in the past so...gave him what he wanted.
The bike: Tank was original but repainted Sterling Moss (green) and white. Very nice tank. Forks were in good shape except the upper yoke was destroyed by someone trying to remove the fork lock. Engine is fine. Frame is okay (rusted a lot). Everything else has to be replaced or re-furbished. If it was painted, it was rusted and chipped. If it was chrome it was rusted and pitted (wheels and fenders). If it had a bolt, it was rusted and most were seized. So far have spent around $5000 on parts (fenders, new repop seat, entire wheels and tires, speedo replaced with a refurbished Smiths, headlight shell, warning lights, cloth harness, every nut and bolt and screw, top yoke, new fork lock, new ignition switch (correct NOS with internal lock with keys), and so on and so on).
I know the bike will not be worth what I am putting into it, but...it is a hobby and keeps me in the motorcycle world that I have been in since I was 15 when I got my motorcycle permit. Can't live without a motorcycle! Has been my life.
Anyway....to my question:
1. As I said, all the bolts on the bike were rusted and most seized. Took me over 2 hours to get the swing arm bolt out!! Had grease the bearings, then spray it with a penetrating spray and wait (multiple times). Finally got it pounded out....now my problem...the "Engine Fixing Bolt" (bolt through the bottom of the frame through the bottom of the engine) is seized...got one nut off, the other close to rounding it before I stopped. Have used liberal penetrating spray (Blaster is the name of it). I tried pounding it through but am concerned about wrecking the cases the bolt goes through. ANY SUGGESTIONS? I took off the front and back engine mounts and tried lifting the engine to take stress off the bolt...nope. I put the front and back engine mounts on and tried pounding the bolt out...nope...at a loss at this point. Any tricks?
If you could get the swingarm pivot out (which is something that most of us cannot do without torches and hydraulic presses!) you'll figure out the engine mounting bolt. That bottom one is always the worst because it's the one most slathered with road dirt and corrosion.
Since the bolt goes through the engine cases and the frame bosses, and since the frame bosses "protect" the cases from twisting and breaking under pressure, I think you'd be safe in (A) trying to get some sort of anti-corrosion 'stuff' in there, like a 50/50 mix of ATF and acetone and (B) patiently "pounding", using some mechanical sympathy but being firm about it, until the corroded-in-place bolt moves. If the steel bolt is in fact "welded" to the aluminum cases so that it won't come out this way, you're looking at a machine-shop repair anyway, so it's worth a try. (Says me who has no skin in that game!) I'd also try a heat gun liberally played on the cases until they're too hot to touch where the bolt goes through, and then whack it .....
You said a mouthful when you said "The engine is fine". To me, the only way I could make that statement is if I was in personal contact with an engine rebuilder of KNOWN competence (and this wouldn't include people who might be experts on Triumphs and Sportsters and small-block Chevys and therefore don't know how to clean a sludge trap, line-ream a crank bushing, or shim the crank end-play), who has given you every detail of what he did to this motor, and you believe him .... If I didn't have all that, the motor would be coming apart down to the crank ....
Good luck with it all! They make nice-riding bikes when you're done, and generally the only one on the block ....
First of all--welcome to the forum--and congratulations on staying with a bike! Not a bad choice of bike and don't worry about paying "too much". As you say it is a hobby and no bike has a "right" price decided by someone who has not bought it. Only the buyer sets the "right" price for that bike in that place at that time. Ref the engine mounting bolt---no short cuts IMHO. Use plenty of PB Blaster, use a lot of heat as the crankcases are real heat sinks and use force. Ref force--no gentle taps or even repeated hard thumps but rather a really good whack with a lump hammer to really shock the corrosion between the aluminum crankcases and the steel bolt--which is holding it in. HTH and best of luck!
Whew! Got it out! Laid the bike on its primary side on a carpet. Took my mapp gas torch and heated the bottom engine cases and frame. About 5-min of heating. Was able to drive it out. Lots of rust and bits came out with it!!
Hope the case bonding is okay (no leaks).
The engine. Not a novice to bike engines and engine rebuilding. Usually restore bikes back to all oem condition with NOS parts. Last one was a Harley 1981 FXS Lowrider. Complete frame/engine build. Sold to a motorcycle shop in Japan. Was in the window of his shop in fact (got pictures) to draw In customers. I did the whole restoration myself. Not doing so with this BSA.
I guess I am saying that after riding the bike and listening to it with my stephoscope I am real comfortable with the engine as it is. I would not have bought it If the engine in my opinion was bad or needed work.
Hopefully I am correct......I could eat my words in the future...hah!?
Lannis, thank you so much for replying to my issue! many thanks! Applying Heat was correct. It was going to be my last option anyway. You saved me time and cases by bringing it up.
Congrats on the bolt removal. heres a coup[le of tips for the 71. Its maybe too late , but the bottom mount has a steel spacers between the frame and motor, if there is anything left of it make a note of the thickness and what side it was on, its easily lost / forgotten, but it stops the frame springing and helps keep the vibes down.
if you are going to repaint the steel side covers , have a good look at the inside top edge, as stock they interfere with the coil brackets, causing beakage and vibration, the inner top edge can be scalloped about 5/16 " to prevent rubbing off the coil bracket. Best to test fit and adjust before painting. It took triumph till 1973 to scallop them at the factory.
The air box lids centre mount is not easy to use as stock, the airbox inner can be fitted with a 5/16 UNF helicoil , makes bolting them back on a lot easier. HTH
Last edited by gavin eisler; 10/10/178:08 pm.
71 Devimead A65 750 56 Norbsa 68 Longstroke A65 Cagiva Raptor 650 MZ TS 250 The poster formerly known as Pod
I hope I did not come off sounding pompous or a know it all or anything like that with my last reply...not meant to.
I will say I did read all of the 611 posts on this BSA forum before I introduced myself. Learned some good things! Years of BSA knowledge here and everyone seems great!!
Thanks everyone! Engine is out...learned in a few posts that you can remove the engine from the frame by laying it on the primary side and lifting the frame off the engine....worked like a charm. I am going to put the engine back in the frame that way. Good stuff here!
I continue to learn about BSAs...I never knew BSA owned Triumph...I thought Triumph owned BSA in the 60's/70's. VERY interesting. What I like about my BSA is....none of the bikers today (unless you are older) even know what a BSA is.
In the middle 70's I rode with 10 Triumph riders and 1 BSA rider. We hung out together as the Harley guys didn't want to be seen with the "slimy limeys" as they called it. My 1965 TR6 blew away most of the Sportsters back then though...hah!
I was never a fan of the OIF Triumphs when they came out. I thought the OIF 1971/1972 BSAs looked so much better. I joined the Navy (late in life...I was 23 at the time....Nuclear powered fast attack submarines) and made it a 20-year career. Once I got to my first submarine, I bought a 1975 Sportster and then owned Harleys after that. However, I ALWAYS had a LOVE for the British motorcycles...dunno why...just thought the engines were beautiful looking and just classic! Great to be back!
Thanks again to all, looking forward to learning more on this forum from the great people here.
When taking the lower engine bolt out, leave the front bolt in, remove the rear bolts/plates and use a pry bar or wood wedges to lift the weight of the motor off the lower bolt. You can fix the side cover bolt by adding a snap ring on the outer side of the bolt from the inner case. That will keep the bolt head from pushing in past the cast-in shoulders. At least put an oil pressure gauge on it to test the hot pressure then you can go back to just the light.