stpauls

You take the plug out and kick the engine over. There is a spark. You replace the plug and kick it over repeatedly, but it won't run: Look at the green ignition wire very carefully. It connects to a small bolt on the points via a small brass fork terminal. If that fork terminal is not fitted squarely onto the points connector, then it may/will arc across to the ignition carry plate, or even to the points cover when the spark plug is under compression, in the engine. If the fork terminal is placed on the outside, under the bolt's head, then it WILL arc across to the points cover, when under compression. Put the bike in a dark place - shed or garage. Turn the lights off. Take the ignition cover off. Get someone to kick the engine over while you look closely at the points. The point's contacts may/may not/sometimes spark. Disregard that. See if you can spot a spark elsewhere. That will be your problem.

Forget the price. A 300cc trials bike is much more difficult to control than a smaller bike. 250cc is more than enough for a novice. 200 even better. 125 would also be fine to learn basic trials riding skills. The last thing you need as a novice is too much power.

I wonder if your TL 150 Honda "in a Mick Andrews Tallboy frame" is in fact a TL 150 Honda, in a Sammy Miller Highboy frame? From 1975 to 1980 – THE HONDA TRIALS HISTORY (onlytrial.com) http://onlytrial.com/wp-content/uploads/2020/03/Frank-Brzeski2.jpg

Here in the South West of England, we don't ride Christmas Day or Remembrance Sunday. Other than these two "sacred" days, there will be multiple trials meetings held on any weekend, or Bank Holiday, usually within a 50 mile radius of my home There are even a few trials meetings held mid-week in the summer months! We are blessed!

Tank sealers: I've used Kreem. Rubbish - failed within weeks. Flowliner. Failed after 2 years. This was despite draining the fuel tank after every trial.

"In the slop". There's pretty!

Take it to a bike shop and ask them to sort it out for you,

Don't waste your money. Find something else.

CB125 Archives - Charlie's Place (charlies-place.com) See Honda XL125

I was thinking that before I read your post.

"Did not respond to lanyard". Do you mean that you have a magnetic lanyard cut-out/kill switch, but when you pulled it off the engine kept running? Or, do you mean that it did not respond to the throttle? Important to be clear, because they would have two completely different causes and therefore solutions. I suspect you meant throttle, in which case my best guess is that the throttle cable was not seated correctly into the top of the carburettor, or that the cable was not seated correctly into the throttle. A third guess is that the throttle cable was not seated correctly into the carburettor slide. Engines have been known to race at full throttle even when the kill switch has been off, but this will have completely different causes and solutions.

A trail bike really, not a trials bike. Not the best bike to start learning to ride trials on. Much, much easier to learn on a modern bike.

GET ON AND RIDE THE BLOODY THING!

A view of the other side of the bike would help.

Two main issues with the rear tanker Shercos. 1. The steering stop chops through/dents/collapses the frame down-tubes - look and you will certainly find! This seriously weakens the strength of the tube and the frame. (Some people had new frames from Sherco, but I guess it still happened again). 2. The tank plumbing is overly complicated. The 2 feet of plastic tubing WILL perish/crack/become porous, resulting in all kinds of weird and wonderful issues, until it is completely replaced with new plastic tubing - perhaps every couple of years. Cheap enough if DIY. Other than this they are good bikes!

Honda TL 125 Q1. Has anyone replaced the points ignition on a Honda TL125 to an electronic ignition system? Q2. Has anyone used a Pitbike ignition to convert points ignition to an electronic ignition system on any other make or model? Thanks

NGK BPR4ES 7222 Spark Plug Copper Core (gsparkplug.com)

"We lack the space you guys have". Exactly.

"Some of these older twin-shock bikes are older than me". Some bikes aren't as old as they might appear. You can buy a Drayton C15/B40/Bantam, which was built last week but is apparently eligible to ride in Pre 65 events. Or, what about a brand new Villiers or Greeves - all eligible too, apparently! If you are considering buying a modernish Monoshock trials bike then the newer, the better, because some spares for the early ones are virtually unavailable and costs for rare spares can soon add up and go way beyond the actual value of the bike.

You could remove the spring from the foot-peg, so that you can fold it up out of the way before you kick it. An extra washer will stiffen it up.

The Beta Clutch Fix works for Gasgas too. Best read the article.

Click on the link and read the article.

Clutches on new trials bikes don't USUALLY drag. However as the bike gets a bit older, many/most trials bike clutches drag when the engine is cold. They usually stop dragging when the engine warms up. But, some will drag when the engine gets really hot, then ease off as it cools down to more normal operating temperatures. It must be due to fine tolerances, wear and adjustment. Have you tried the Beta clutch fix?

I admire your calmness, persistence and restraint.

Most people in the use 99 octane in their bikes, not 95 or even 93. Higher octane = smoother running, quicker response and greater power. Use a much higher octane fuel than 93 and don't worry too much about squish bands. I'm guessing that you are not based in Great Britain? If higher octane fuel is not available in your area, then consider using an octane booster or even Avgas.