Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board 1967 Bonneville kickstart stop

Can anyone tell me if they make an oversize kickstart stop [Part No. varies...T45 for 1966, 57-0045 for 1980's if that helps]. Its the stepped pin that is a press fit in the inner case.
The bike I am working on kickstart stop almost fell out of the case, the hole is ovalled, and the kickstart stop has been centre punch knurled before. So I can't see Loctite etc working.

If I can't get an oversize one then my plan is to enlarge the hole to true it up then make a press fit steel bush. Then turn the original kickstart stop down to true it up and then press fit this into the hole in the steel bush.

But if 750 ones are bigger or something then I'll rethink the problem. I have a 750cc and a Trident but they are together, not tearing them down to see

Also, I took the patent plate off and two of the pins came out no problem, but one snapped off flush. I tried using a Dremel and grinding some of the case away, but unless I go severe, there is just not enough exposed pin to get a set of sidecutters onto the end.....never had it happen before, bloody frustrating.
TIA

Don't know about the ks pin but a bush sounds favorite.
The patent plate remedy is to plug the original holes and move the plate a little then re-drill
all three. Done that a couple of times, if you're careful you only need to move it a few mill.

Thanks Nick, I actually thought of drilling from the inside of the case until I hit the pin then drive it out from there? But this would require a steady hand on the drill press [I'd need at least a six pack :)]. I assume those 'pillars' correspond to the pin positions?

All the Early ones are usually loose like you say, they re inforced that area on the later bikes. What i do is true up the hole and but a small counter bore in the case. Make any oversize pin, and thread the inside. FLip the cover over and mill a flat area around the bolt hole. Shrink fit the new pin you made in at .0015 and then bolt it in from the rear. Its pulling up against the counterbored area. Its some work, but never had that issue again

JB weld works

I like that idea JakeH...I will do something like that. So a new 3 stage diameter pin that is say 3/8" longer with a threaded section for that extra length - enough so that a thin nut can be used on it.

Hi tridentt150, Regarding kick start stop pin. I checked my spare T140 inner cover. Hard to get calipers straight on pin so these are approximant but will get you close.

The outside of large end gear stops on is .560". The small end hole is .370". Again aprox. I've never had one of these out. Visually from photos it looks same as 650.

Drilling & making new pin is an excellent repair. Also You could drill & tap it & use bolt to secure it from back side. There is room behind the inner cover for this if you use allen head bolt & hardened flat washer. Drill with drill press if possible.

I've done quite a few patent plates. The key is use regular pliers with serrated jaws. Look at serrations. Grind tip of jaws until a nice clean fairly deep serration is at end of jaw. This allows pliers to grip side of head yet not put too much strain on shaft. Side or end cutters will often fracture the shaft.

I then tear off patent plate. Get small screw driver under it & lift. The tear off with pliers. I try to pull such the aluminum tears through at corner so I don't end up with ring of patent plate around rivet.

I thin put pliers on rivet head & look to see how the jaw tip fits. You want the last serration narrow enough to cleanly slip under rivet head, yet leaving as much jaw as possible so jaw doesn't bend or break. The rivet is fluted so it will need to rotate counter clockwise. However you hardly turn it. It only rotates slightly. Turning too much will fracture it. So pull straight out with only a slight counter clockwise rotation. If rivet is stubborn which seldom is, stop! Heat cover with heat gun, then continue.

I have dedicated pliers ground for this & use them for nothing else.

If I had a broken rivet I would personally remove cover & set cover on drill press. Drill through rivet with a very tiny drill right through cover. This will show exact location of rivet on back side. Then drill this pilot hole just enough to get a small punch through to push rivet from back side. I use short length of music wire (piano wire) for a punch. Grind both ends of wire very square. Make length only about 3/16 longer than hole is deep. Even less is rivet is stubborn. Then drive rivet. Make longer punches as needed. I would expect 2 or 3 wire punches. The hole will support wire & give good push so long as wire doesn't stick up too far on back side. I've done this on other rivets to good results, but never on patent plate. Music wire is available online or at hobby shops where they do RC cars & planes. Of course don't enlarge hole for rivet.

I would put new rivet in drilled hole with a sealant. Loctite 243 would work, but sealant 510 or 574 would be my first choice.

The real name of these rivets is drive screws. They can be had larger sizes & in stainless, but you'll need to shop around. As shank gets larger so does head. If worst came to worst you could get 2 correct size rivets & 1 larger. Then reprofile head to match correct size. Never done this though so you'll need to see what's available.

Generally I'll put a tiny smear of water proof grease for boat trailers on new rivet. Helps keeps it from rusting into hole. However a tiny bit only as you don't want to get grease down hole & have it hydraulic against rivet. Same with sealant in blind hole, You can easily split a case like this.
Don

Don, thanks. I've done quite a few pins and this is the first one that I've not been able to extract. Generally they all come out quite easily.. And this one didn't break where I gripped it, it was further down. At this stage I think I will grind more of the case way and try to access the remaining pin and remove it, then weld up the case, reshape, and drill a new hole using the patent plate as a template. PITA, but it can be done.

Drilling through the rivet with a tiny drill ….well McGyver could do it, 007 and Tim the Toolman would also show us how its done, but us mere mortals would see the drill bit snap or skew off into the alloy...….and I have the drills and a drill press, but I'm not McGyver. So tbh O think I would be wasting my time pursuing a futile remedy.

The kickstart pin will be sorted soonish, its no bit deal just another PITA. Be better if these things never happened tbh, but it is an old British motorcycle and these things are expected.

Maybe there's a market for pseudo-stick on plates with rivet head bumps? Just a joke for Xmas, have a good one all!

T150v . i drill and tap the inside of the new pin to 1/4-20 and run a bolt and washer, from the back side. Be sure to make the pin a little shorter then the bore so the bolt is pulling the pin in all the time! About every early one i take apart needs it!

Nice, thanks! I usually just turn up an oversize one but that should put a permanent stop to it.
It's when people kick the engine over and just let the pedal bang back against the stop it happens. If you take a couple of seconds and ease the pedal back it won't.
Changing people's habits won't happen either though! So +1 for that mod, I'm going to adopt it from now on.

SR

SR, Yes your right!! I see guys all the time just slide their foot off the kicker at the bottom and let it slam back !! these bikes are pretty tough, and if you use a little common sense and develope just a little mechanical knowledge they will last a long time!!