#yourProject – Dynastarter – Group 9

The Dynastarter – from charging and starting

In this article we deal with topics such as field coils, anchors, coals, but then also air gap, anchor turning off, collector saw, closed ball bearings, insulator discs, strong soldering iron, counter holder fan wheel, abrasion, 20 amperes… Our thanks go to our 2 Bosch specialists G&G.

Work: 2 – 10 hours
Material: 20/30 – 180/350 Euro
Tool: standard plus soldering iron, mounting mandrel

Dynastarter Overview

Dynastarter Bosch 0 010 350 003 or LA/EJ160/12/3000+R, 14V 20A, 12V 1PS

NOTE: This article is very extensive and is constantly being supplemented in partial steps, also in coordination with our experts and further screwdriver feedback.

What is going on?

The battery no longer charges, but the controller is fine. The boxer engine no longer starts or the starter only turns weakly. Also not by means of a separate battery, ignition on and 2 starter cables? The plus cable directly to the large threaded pin M8 on the dynastarter, terminal 30 (gearbox in idle!). At the latest now it is time for an inspection of the Dynastarter. The alternator has an output of 240 W and requires a controller with 20A. The starting power is given as 1 hp.


We start by loosening the mother of the fan wheel. The fixation is carried out by counterholding with a large screwdriver on the large sprue on the front bearing plate. Depending on the position of the counter-holder, it can already be seen whether a hand has already been applied here. More on that later. The dismantling of the connected cables must be done with the utmost care. The 3 threaded bolts Kl 30, D+, DF must not be turned! At their ends, the wires of the field coils are soldered. Also, the screw M6 of the ground connections should not be too long, at the end a coil package waits for its short circuit. The dynastarter is removed from the engine along with the air guide wheel. On the underside of the Leitrade sits a fixing pin, which later has to intervene again in the engine housing. Now on the workbench we loosen the rear clamping tape. The Dynastarter is connected to the guide wheel. In this clamping belt sits a pin for fixing, which reaches into the housing of the dynastarter. This clamping strap can be mounted in two positions, only ONE is correct. Recognizable by the daring position of the clamping screw. In addition, both clamping screws are inserted from right to left into the belts, seen in the direction of travel. The removal of the starter from the guide wheel to the rear, goes from slightly to hard-necked to not at all. The desired effect is often demonstrated by means of rust removers, the underlay of wooden blocks, a large nut and a plastic hammer. Targeted use of heat can work, the use of a hydraulic press usually costs the guide wheel. Last but not least, we dismantle the carbon protection belt at the end of the starter. The carbon abrasion deposited there on the conveyor belt is an indicator of the previous service.

Let’s go now!

Now he’s there, the heavy dynastarter. What kind of service is required? Is everything glued to carbon abrasion? Are the coals used up? Are the camps running rough and making noises? Is the electrical part defective? 

Replacement of coal

A coal exchange can also take place without further disassembly. However, it is up to each person to decide for himself whether this is a good thing. After all, the abrasion did not dissipate. Also, the career on the anchor has mostly run in. There are generator carbons on the market, but they are not suitable for use in our dynastarter. New coals need to move easily in their guides and require a run-up time on their careers, so there is an increase in spark formation at the beginning. 

  • Coal Old New
  • Bearing shield coal side

Replacement of the bearings

The bearing plates at the front and back are held with small slotted screws. The positions for the reassembly result in the front by the already described counter-holder for the fan wheel and at the back on the carbon side by the asymmetrical hole arrangement. NOTE: The front bearing plate has a symmetrical hole pattern, the counter holder can sit in the wrong position if it is mounted in correctly. The correct position is at 11 o’clock. 

With a suitable pliers, the coal holders must be held against, while the coil flags are loosened with a suitable slotted screwdriver. Only then are the slotted screws of the rear bearing shield dismantled and pulled to the rear along with the coals. The front bearing is fixed with four additional screws in the bearing plate. These are additionally covered with a screw securing varnish. When dismantling, the bearings of the cover discs and rings must be taken into account. There is a corrugated disc in the rear bearing lid. This is not shown on the explosive drawing and unfortunately no longer available. The old, open ball bearings are now removed by means of suitable pullers and replaced with modern closed bearings. The old cover discs are no longer needed, but are required for the maintenance of the axial play. For the assembly of the rear bearing shield, the coals are NOT inserted into the guides. 

Coils and anchors

This is where the part for the pro begins. 

Possible errors:

  • Insulator damage to the connections
  • Wires of the field coils broken
  • Insulation damage of the field coil
  • Dark spots on the collector segment
  • Collector run in

Insulator damage

Often the old insulators are broken. If these need to be replaced, the wires of the field coils shall be soldered with a strong soldering iron. 

  • Field coils
  • Field coils 2

Field coils

The coil packages in the dynastarter each contain one circuit for starting and one for generator operation. The interconnection is visible in the built-in state and on the photos. There are 4 different field coils installed, which are not interchangeable in their positions. The soldering flags for fastening to the coal holder are usually not newly available and must be reused during replacement. The coils are not currently available at Bosch, but often from the relevant Puch spare parts dealers.

The field coils are held in the housing with 4 retaining plates and fastened from the outside with 4 slotted screws. The distance between the retaining plates and the anchor is a crucial component for the performance of the starter. If you look closely at the retaining plates, you can see differences in height. This is due to factory post-processing by means of a cutter after assembly of the coil packages. For removal it is therefore recommended to mark the positions, for example with grain points on the plates and on the housing. An assembly mandrel is required for assembly.

  • Mounting mandrel field coil plates


The anchor is not currently available at Bosch, but at times at the relevant Puch spare parts dealers. That’s why we’re dealing with the used part here. In the case of a large revision, it is recommended to overturn the collector carefully and very low. This reduces the grinding time of the new coals, the initial excessive spark flight and thus the loss of power. The required gap between the segments is cleaned with a collector saw. This can be made from a small, thinly ground metal saw blade itself.

The end of the anchor windings are the collector segments. These can be checked with an ohmmeter. If dark segments occur during a visual inspection, the anchor is usually defective and must be replaced.

  • Turning off the collector
  • Collector saw


Carefully clamp the dynastarter into the vice, provide the battery and two starter cables. Minus to the vice, plus to the plus pole of the dynastarter give standing bolt M8, do not frighten! Without a big spark on the coals, the anchor should move. A professional reports that he lets the coals run in briefly with this procedure.


  • Bearing 6203 2Z (closed)
  • Bearing 6202 2Z (closed)
  • Coal Bosch 2 017 014 105
  • Set of coils
  • Anchor
  • Insulators

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