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If you really want to stick with points you will have to work through this systematically.

Meaning: Make a proper diagnoses before swapping parts.

1. Did it run right before? Y/N
If yes: What changed that caused this behaviour? Perhaps you did some work to the bike and damaged something in the process. If it appeared all of a sudden while the bike always ran fine it's probably due to wear or a faulty part.

2. Check basics first: Compression (you say is OK), check spark: (you are not sure), check air/fuel delivery (you say it's OK), check charging system (you didnt check yet)

If you can eliminate the standard suspects you end up with the culprit.

Unfortunately, as mentioned before, diagnosing these old ignitions can be a real pain. There are many things that can cause your symptons.

- bad spark plugs
- bad spark plug wires
- bad spark plug caps
- bad coils
- bad condensator
- bad points
- bad point vilts
- uneven cam on camshaft/unbalance, but this doesnt happen all of a sudden
- flywheel damage
- rectifier/regulator faulty
- generator faulty
- battery faulty
- bad wiring in/to all of the above
- bad timing

You claim its always the left cylinder and the problem doesnt move to the other cylinder despite swapping points, coils, etc. This makes me believe it's either an ignition wiring problem to the left cylinder or a mechanical problem (cam on crankshaft uneven). As mentioned before, the latter will not happen all of a sudden.

Check your wiring from the point all the way to the ignition coil on the left cyliner, wiggle it a bit while measuring and see if you lose continuity.

Dave

Not to be rude but let my suggestion sink in. Points are outdated technology plus the mechanics/electrics are 50y+ already. They fail and are hard to get back to original condition without spending a fortune and you still end up with suboptimal performance and reliability.

I know its not what you want to hear but if you want to enjoy these bikes without too many worries it is the best option.

Been there done that, after many hours and replacing almost the entire system I chickened out and bought an electronic ignition. Best decision ever and I put it in all my bikes once the points ignition develops issues.

Its not only the points, the charging system is also 50+ y old and bound to fail next, then you can open the next topic wondering why its not charging.

To be honest.. I would just ditch the entire ignition and replace is with a modern VAPE ignition. Yes, its not cheap but the best upgrade for these bikes. I ended up spending way too much time on my historic points ignition. As soon as they give problems imo its better to replace for an electronic ignition.

Oh and ps: ditch the Chinese barrels as well. Get your original cylinders bored to next oversize and put some mitaka pistons in it, they are not expensive. Thank me later.

might want to take the carbs off and make sure the choke passages are clear.

This actually solved the problem! The choke pickup in the fuel bowl was blocked, thanks a lot for this tip!

might want to take the carbs off and make sure the choke passages are clear.

Good one ill give that a try

Choke is working on both carbs (at least the plungers are retracting fully) and I tested the petcock, its really not leaking.

Thanks for the suggestion. A new oem petcock is on the bike and it aint leaking.

It does smoke yes and the first miles its not reviving up throughout the entire rev range (with lot of smoke), after that it runs perfect.

I am the proud owner of a stock TDR250 since a couple of weeks. Bike came as a non-runner but I went through it and it now drives perfect.

The problem I am having is present when the engine is cold: It will start very hand and once it starts it only runs for like 2 or 3 seconds and dies as soon as I hit the throttle. If I dont hit the throttle it will run for a couple of seconds more but eventually will also die. It just wont get going, also not with the choke on. As soon as I spray some carb cleaner in the intake it fires up straight away and there are no more issues, it responds to throttle perfectly and it will idle/run forever. The bike runs like a champ at all throttle inputs and throughout the entire rpm range. It idles perfectly, picks up throttle perfectly and storms to 10k rpm easily.

It sounds like a fuel delivery problem but you would expect this to be present even after introducing carb cleaner, which is not the case as it does keep running.

What I did already to the bike (im not sure if the issue existed before I did these things as I didnt got it to run):

- Compression test (115psi both cylinders)
- New NGK spark plugs
- New OEM petcock
- New fuel lines
- Rebuild both carbs with yambits rebuild kits
- New exhaust gaskets
- New stock air filter

I did notice an intermittent fuel sweat/leak from the left side carb where this hose connects. See red circle on picture.

Thanks for any ideas here

Use twnkcure

Thanks

100km or so

Hi all

For testing purposes I want to temporarily use premix instead of the oil pump. Can I leave the oil pump on or will it be destroyed die to lack of lubrication?

Its a tzr250

Thanks

Thanks, that clarifies!

Hi all

I'm a bit puzzled how the turn indicator light should function. FYI This bike is new to me and the light didnt ever work since I have it.

Situation: All 4 blinkers flash but the turn signal light doesnt flash.
What I checked: Put 12v straight on the wiring to the indicator light (ground + 12v) and the light came up.

I checked the wiring diagram but it looks like there isn't any ground going to the turn signal indicator bulb. How is this supposed to function? From the looks of it 1 wire is for left positive, 1 for right positive, but where does the ground come from?

Thanks for the insights already..

Dont use double washers, they will deform. Use one thick one.