This blog is an archive of DKW related articles, manuals, brochures and posts. It also covers East German successor marques, such as IFA, AWZ, Wartburg, Sachsenring, MZ and IWL.
After taking the bike for quick test ride it was apparent the engine was low on power, especially in first gear. There were a couple of items I decided I needed to check. The first was to clean out the exhausts, which I was certain were carrying some 80 years of baked in oil residue. The exhausts came out easily enough and quick tap confirmed my suspicions.
The lumps that simply fell out of the exhaust pipes were like little lumps of coal!
After a good tapping I had more than a handfull of coal.
A view of the baffles at the fishtail end. Pretty black.
Next step was soaking the exhaust parts in kerosene to loosen the oil residue.
A look down the silencer shows the state of the baffles. After soaking in kerosene I was able to scrub out a lot of the residue. It wasn't perfect but it was enough to clear the baffles.
Someone suggested to me that you could burn out the remaining residue, so I gave that a go. Unsurprisingly the exhaust 'fired up' and burned for about half an hour, relighting itself periodically with a big 'whoop!' After another round of cleaning up and scrubbing off dirt, mud, oil and rust, I reassembled the pipes and refitted them.
I took the bike on a test ride to the Arthur Grady Day on Saturday 17 May 2025. The exhausts smoked a bit and needed some tightening up afterwards. Power is still low, especially in first gear. Next thing to do will be to re-look at the gearbox and clutch lubricant as I think it may not be right. https://heinkelscooter.blogspot.com/2025/05/arthur-grady-day-may-2025.html
I picked up my DKW SB350 at the end of April but I did not get a chance to do anything with until the 1st day of May.
First things first was to try and start it up myself. The choke needs to be on (lever turns towards the rider) and after only a few kicks - during which is made almost no compression noise at all - it fired straight up. The engine quickly settled into a steady idle. Even my 1954 DKW RT250 doesn't idle reliably unless its had time to warm up. After a quick walk around to test everything, it was time to take it for a test ride.
Wayne and Kim had both test ridden the bike as they worked on it and neither had been particularly excited about it. Both reported it was complicated to ride. There were good reasons for this. When Wayne took it for its first test ride, the clutch was barely functional. The clutch has now been recorked. Kim took it for a test ride after reinstalling the clutch, but he found that the replacement clutch cable was about a foot too short, so used the foot clutch. Using the left foot clutch and the right hand gear shifter requires quite a bit of practice on an unfamiliar bike. So I had been prewarned.
I decided to reuse the old clutch cable which, being original, had decent tension adjustors at both ends, so I was able to install and get the correct tension on the hand clutch lever. I must say, I have been very frustrated with many of the reproduction parts, especially the cables. They never fit and are often the wrong length - in this case a foot too short! That's completely unacceptable. This meant not having to worry about the foot clutch pedal. I quickly realised that the foot gear shifter was difficult to use due to its positioning, but the hand gear shifter worked well, so I stuck with that.
My first riding impression was of great instability. This was due to the seat which was not firmly mounted at the front bracket, causing the seat to slip several millimeters each way as you turn. This movement was very disconcerting but was an easy enough fix. I removed the (non-original) bolt securing the seat to the frame and packed in several washers to stop the front of the seat slipping. This allows for the rear-mounted springs to provide cushioning, but not slip from side to side.
The rear wheel foot brake (right side) feels poorly placed. Its obviously placed where it is for heel use, but it needed a lot of adjustment to stop the bike effectively without needing to move your foot too far back. Adjustment was easy enough as the brake rod has a decent adjustor. Fortunately the hand brake was extremely effective and I didn't need to use both brakes on the short, rather slow test ride around the block.
Which brings me to the last thing - power. The engine ran really flat and it was hard to accelerate. There are two things to look at: 1. the exhausts need a damned good decoking. At the silencer end they are completely filled with oil. After another test ride to confirm the brakes and seat issue is solved, I'll remove the exhausts and give them a good clean. And 2. I need to check the carburettor settings and possibly the jet size. By all accounts these bikes will comforably do 110 kph. I think I'd push it to get over 50 kph at the moment.
All in all, a good first test and I think I know what I'm doing now. A big thanks to Wayne, Kim and Gavin for helping get this far.
