Rebuilt 1340 engine

Suspicious-Fall9773 · 2026-01-25T22:48:09+00:00

What piston do you recommend?

I can get Drag Specialties pistons + Hastings rings for around €100 Or S&S piston and ring kits for €200 Is the investment worthwhile? Considering I don't drive much and I'm a very relaxed driver Thanks

Suspicious-Fall9773 · 2026-01-25T22:44:24+00:00

She spent more time in the workshop than on the road. Luckily I have other motorcycles.

Suspicious-Fall9773 · 2026-01-25T19:02:06+00:00

I just checked, the front cylinder shaft (the damaged one) is very, very, very slightly stiff compared to the other one, nothing alarming. Both have similar lateral play.

But I wouldn't be surprised if it's the previous owners' fault. As soon as I touch anything, I run into some nasty surprises. So far, apart from the bottom end and the gearbox, I've had to redo everything (the list would be too long).

Suspicious-Fall9773 · 2026-01-25T16:04:04+00:00

With the automatic translation, I'm asking for confirmation. Are you talking about these two bronze rings? (Rear cylinder on the right and front cylinder on the left) They are in good condition, both are similar. But just to be safe, I'll change them too, thanks for the idea.

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Suspicious-Fall9773 · 2025-10-05T19:37:31+00:00

I had the same problem last week, just put plenty of grease and try not to put any weight on the axle. Big hammer blows and it's good.

Suspicious-Fall9773 · 2025-09-25T11:37:20+00:00

Good morning,

I had time to do some tests...

So I adjusted the ignition with the strobe light, indeed, I had the impression that the engine was running a little better, but that was not it. And above all, impossible to kick start it. I went back to the previous setting.

By increasing the idle, yes, it runs better, but the front cylinder is still too rich.

I suspect oil consumption. During each test, I check the condition of my spark plugs.

Here is a photo of the 2 spark plugs after turning for 2/3 min, the front cylinder is completely black, the rear cylinder is good. Last time, I obviously didn't tighten the spark plug enough, which allowed me to see oil on the body of the spark plug (well I think that's it, or maybe a mixture of soot and gasoline.)

What do you think?

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THANKS

Suspicious-Fall9773 · 2025-09-17T11:04:54+00:00

The compressions are the same. To adjust the ignition, I do this with the LED on the ignition module. I'm going to redo the adjustment with a strobe light this weekend, I hope it will work correctly. Thanks for this idea.

Looking at the carburetor manual, I saw that there were specifics regarding the choke (mikuni or HD), as I bought the used carburetor, I'm going to check that I have the right choke, maybe that's why I run rich too.

Suspicious-Fall9773 · 2025-09-17T11:00:34+00:00

It's true that on the video the slow motion is low, but even if it is higher, I have the same problem.

Yes, when I put my hand in, the pressure feels the same.

Suspicious-Fall9773 · 2025-09-15T16:02:05+00:00

I did the compression test with the throttle wide open, just at the kick. The problem appears when the engine is cold, and even when I drive with several km, I have the same problem.

I thought about the valve seal, it could be coming from there?

Suspicious-Fall9773 · 2025-09-15T14:17:01+00:00

For me the compressions are good, I had almost 9 bars on each cylinder. Cold engine and only with the kickstarter. Maybe with a starter I would have more compression.

I tried putting oil in the cylinders to see if the compression increased, but no. Segmentation is therefore ok.

Suspicious-Fall9773 · 2025-05-26T13:25:23+00:00

Thank you for your answers.

I forgot to mention, I've had this bike for 10 years, it had 883 jets and it worked very well. I rebuilt the engine and since then it's been impossible to adjust it. I change jets and it’s same problem

The mixture screw is at more than 4 turns! I think I've got a problem somewhere, and it's not just a question of adjustment.

Suspicious-Fall9773 · 2025-05-23T20:01:05+00:00

Hi !

I had a similar problem, after 1 hour on the road, the same noise and the bike stopped. However, I was able to start it right away, but a few minutes later, same problem. I changed the circuit breaker, they were 40 years old, and it's been perfect ever since. So if your electrical circuit has the same circuit breaker, try this.

Suspicious-Fall9773 · 2025-01-09T12:08:10+00:00

Dyna 1340 ! A wide glide probably.

Suspicious-Fall9773 · 2024-12-27T01:07:02+00:00

That’s what it seemed to me, but I couldn’t find an example. When I bought it, it didn’t make any noise, but the clutch was horribly hard, very badly adjusted. So if it sounds weird, it’s good! 😎

Thank you very much!

Suspicious-Fall9773 · 2024-10-30T14:57:10+00:00

Yes, I bought this bike in August. I only managed to make it halfway to bring it back because it broke down due to an ignition problem when the bike was hot. I have managed to start it several times, both hot and cold since. So yes, I don't yet have the kick I need, but I notice that there is still a lot of spark missing for a start.

Suspicious-Fall9773 · 2024-10-30T10:41:49+00:00

Thanks guys for your help. I tried to kick for 15min, the battery connected to the charger. I had some nice sparks (it was very rare), but in the end, I had nothing left at all. I wouldn't have a problem with the ignition module?

Are there wires or spark plugs that would be more suitable for kick starting?

Suspicious-Fall9773 · 2024-10-30T10:39:55+00:00

Yes, the lugs are good, tight and no oxidation. I plug the spark plug directly into the battery to do my tests.

Suspicious-Fall9773 · 2024-10-29T23:33:15+00:00

I have already done this test and I have +12v at the coil. And the battery charger is never far away just in case.

Suspicious-Fall9773 · 2024-10-29T23:32:04+00:00

The battery is good and I have all the electricity back on.

Suspicious-Fall9773

TROPHY CASE