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I had a "Goldfinger Sprite" and the pictures shown here are just the standard 125cc Sprite. The Goldfinger had a deep glitter gold fibre glass tank, gold painted frame and the Sach's Sunburst engine with the large radial fins on the head and barrel. It was a brilliant little bike, light as a feather and quite responsive. I have been looking for one for years but they are like Hobby Horse pooh.

Paint shops can usually match a colour by scanning what you are wanting to match

Hi all, Beta Evo 2009 250 2T owner, but too many pies mean I am about 100kg. The shock is almost bottomed out with my weight on it, maybe at 16 years old the spring is tired, as well as being too light for me. I think I can get a 'heavy duty' spring new for around £90, but these are stated as being for 80kg riders. Can anyone recommend what I need, and where from? Ideally... has anyone got a second hand heavy spring I could buy? I am in Scotland by the way - but happy to pay shipping.

Been riding some 40 years had three rmx 250. Ran 50 to 1 all day everyday put a 10 oz flywheel weight rode slow to flat out bike loved every minute. At 68 I am doing trials on a 2003 Beta rev3 270 and have been running 70 to 1 since day one with no issues. Going slow with a blast here and there bike loves it 93 octane with full synthetic. On the flip side running a little rich and fowling a pug is better than running to lean and burning a set of rings

That's a very nice manual! Anyone learning to do maintenance on a trials bike (regardless of brand) would be well-advised to study it. Unfortunately, there is almost no content about the gearbox (see page 49).

SamAs, I don’t think I’ll be much help to you but I have a 23 TXT 250 that does NOT whine when shifting to 4th. I think the engines are nearly the same as the 2017 but I could be wrong. I’m no mechanic and there are others on here that will have better judgement than I, but I simply wanted to let you know that in my experience, on my bike, there is no whine shifting to 4th. If there was I would be worried. So far, working on my own bike, I’ve found it’s simpler than I ever imagined to do it myself. If you’re mechanically inclined and have common sense, I’d say go for it on your own. Just review and follow what you find in the maintenance manual if you have it. I’m all about saving cash too. Good luck! you can download the 2018 manual for free here: https://drive.google.com/drive/folders/1xOzbrZQDO_W_AxpjvHU1xJMOqfRsVfPJ

It should NOT sound like it's going to blow up! But 4th gear is "complicated" and actually requires 3 gear pairs to create the ratio. Here is a link to a YouTube video that demonstrates this, as well as the original GG patent in Spanish: https://www.electricmotiontech.com/home/em-factor-e/clutch-gearbox#h.2ajazdf2rs5

Thanks for that. Managed to split the lot and buy just the spacer. Cheers.

Hi all, Ive recently got a 2017 txt racing 300 and it’s making a noise in the gearbox. There is a ticking noise that im assuming is the chain as it does this in time with the master link. But once I shift into 4th gear the box starts to whine like crazy. I know theyre straight cut gears but it sounds like a race car, it’s almost louder than the engine. I’ve been told that it’s a case of possibly bearings or something in the box but seen on an older post on here that the whine is “somewhat normal” im just trying to figure out if I need to take the engine out or not as I’ve never done it before and dont want to do it if I don’t have to. But I want to do as much as I can myself to save money as the bike cost me a lot. thanks in advance for any help, I might end up taking it out soon anyway it’s just a bit daunting

Erm how somewhat normal is the whine in 4th? Because Ive got a 2017 txt 300 and when I go into 4th It sounds like the box is about to blow up

There is a spacer on ebay.co.uk now with a flywheel and weight £52.49. Did you try the importers they list as around $12.

I have a 2014 evo 300 and want to add a flywheel weight. I have a Hidria weight from a rev 3 but suspect I'd need a cover spacer, which I can't find. Does the S3 weight fit without the need for a spacer?

Often, when assembling Bultaco engines the crankshaft will bind on one crank case half after the case halves have been torqued to specification. Generally speaking the crank can be given a quick swat with a dead blow hammer to “center” it in the cases. It will spin freely once centered. Your crank does need to be repaired. The pin isn’t sitting flush on the one side and it isn’t pressed fully on the other. As well there does appear to be a crack in the one crank half. Good used cranks are easy to find and can be rebuilt with a new rod kit to bring back to oem standard. On the inside of all Bultaco crank wheels are balance factor numbers. Be sure you do not have more than a two number spread between the halves. You had also asked about the rod moving side to side excessively. In the mid 70’s Bultaco was having trouble with Sherpa cranks seizing. Most times this would occur during higher speed applications such as riding a road section for several miles. The crank thrust washers were seizing and causing catastrophic damage. The fix was to remove the washers and use small end spacers at the gudgeon pin between the rod and piston to align the rod on the crank pin. Your crank is this design. It’s normal and desirable. It still is pressed together using 22 thou clearance on the crank bearing, and gives a much more reliable running crank at higher rpm. Steve

I want my 2024 sport to sound like Toni's 4 stroke torquer since I've been inundated with his impossible antics on Instagram. I love the one finger diaphragm clutch but to really get the feel of motor /flywheel inertia, I want a low frequency pop instead of the 'zing' sound which is mainly due to gear train noise. So I took a cheap 12VDC car alarm out of the trash and tapped it across two random AC motor phase leads, just for giggles. And predictably, it first smoked a little, probably the 50+ volts into 12 V circuit thing, no surprise. But then it kept working and would produce an ugly growly sound proportional to RPM. I'm not an Electrical Engineer but no doubt someone with circuit design savvy could use this tiny phase lead signal to trigger a proper .WAV file of a single gas bike pop and make a scalable frequency output to a piezo or a speaker. Has anyone done this? I expect it could have its own little battery. Heh, maybe even BT into my hearing aids. Just dreaming but would love to hear if anyone has done anything along these lines?

Thanks for all your help guys. I think I will have the crank overhauled as a result of this discussion.

Can you feel anything with a sharp-tipped scribe? A crack could explain the problem you are having. Another thing to consider is the history of the crankshaft. After repeated pressings, the pin/crankwheel interference fit can become too loose. If you have a dial indicator and a means of supporting the crankshaft, measuring the runout could tell if the crank wheels have shifted position,

No, doesn't appear to be looking through a magnifier.

Is that a crack?

There you go, it is not pressed all the on the one side

Hi all I guess this has been asked before I love the green colour of my Tr77 however the side panels are in pretty poor condition so I was thinking about replacing with pattern part's any help on the nearest to factory green would be appreciated, I'm leaving the tank as it's got some nice age related marks And the plan is just to clean it And then clear coat.. Cheers

Crank pin position

Not sure if you have sorted this out yet. It looks like a 1981/82 model to me. To be sure you could drop a line to In Motion Trials in the UK 01784 440033 and let them have the engine/frame number.

So I looked at your pictures. Show us how the pin sits in the crank from a side view. Most rods only needed 18 thousands clearance. Granted I have luckily not done a bul.

The service manual mentions 250cc - 360cc rod side clearance should be .022 - .024-inch (.55 - .60mm). Section 6 (16 pages) in the service manual is on rebuilding and alignment of the crankshaft.