This “project” bike has over 63,000 miles on it. It’s not uncommon for the timing chain and crankshaft sprocket to wear enough at that mileage to affect valve timing. Too much slack causes uneven timing of the valves. If valve timing varies, then ignition timing will not be optimal. In situations with a lot of wear, the chain can be heard slapping inside the motor. As I’ve never heard this bike run, I do not know if the timing chain is that loose, but that much slop in the timing chain is more common at 100,000+ miles on the chain.

I want this bike to be as reliable as possible because I will auction it for charity to support the Motorcycle Relief Project. So I am replacing the timing chain, the crankshaft timing sprocket, the crankshaft nose bearing, the timing chain tensioner and the slide rail. This requires me to remove all the engine electrical components inside the front engine cover and remove the inner timing cover to get access to the timing chain components. I show how I remove the electrical components in this document.

• 12 BMW 1983 R80ST Remove Alternator, Diode Board & Electronic Ignition Sensor

Tools

I use special tools from Cycle Works to remove and install the crankshaft timing sprocket and the crankshaft nose bearing.

This link shows the three sets of engine tools,  Stage I, Stage II and Stage III., that  Cycle Works provides that include the components above.

• Tools

I also use MAP gas (you can use propane) to heat the inner timing cover so I can remove it.

Parts

All the parts I need for replacing the timing chain components were supplied by Euro MotoElectrics for free in support of the Motorcycle Relief Project. EME provides a kit, EME Part# TCSimplex, with all the parts to upgrade the timing chain components. In addition, I got the crankshaft timing chain sprocket and crankshaft nose bearing. The inner timing cover gaskets are included in EME’s engine gasket kit, EME Part# GSK-EngineKit421

Part #	Description	Qty
BMW Part No 11 31 1 338 185 11 31 1 335 576 11 31 1 335 579 11 31 1 335 584 11 31 1 335 934	EME Timing Chain Kit: -Chain Tensioner -Slide Rail -Piston -Coil Spring -Timing Chain	1 1 1 1 1
11 21 1 335 586	SPROCKET, Crankshaft Timing Chain	1
07 11 9 981 722	GROOVED BALL BEARING – 160 07, Front Crankshaft Nose Bearing	1
07 11 9 932 841	CIRCLIP – D=6MM, Chain Tensioner Pivot	1
11 14 1 338 428	GASKET, Inner Timing Cover (EME Gasket Kit)	1
11 14 1 338 429	WASHER-GASKET, Inner Timing Cover (EME Gasket Kit)	2

Video

Here are some short videos summarizing this work.

VIDEO: 1983 BMW R80ST Remove Timing Chain, Crankshaft Sprocket & Nose Bearing

VIDEO: 1983 BMW R80ST Install Crankshaft Sprocket And Nose Bearing

VIDEO: 1983 BMW R80ST Install Timing Chain

VIDEO: 1983 BMW R80ST Install Inner Timing Cover

Remove Inner Timing Cover

I show how to do this on the 1983 R100RS. In that document I show how to use the Cycle Works tools to remove the inner timing cover.

• 11 BMW 1983 R100RS Remove Timing Chain, Crankshaft Nose Bearing & Sprocket
  • OPTIONAL-Cycle Works Timing Cover Removal Tool

On the 1983 R80ST I use the “heat the inner timing cover” method as described below. The inner timing cover is secured by nine Allen bolts and three special Allen nuts. There is also a thick flat washer under the head of each bolt and under the nuts.

After I remove the Allen nuts and bolts, I put them on a piece of cardboard with an outline of the timing cover and the locations of the blots and nuts. This helps me be sure I have all the hardware. I tape the three washers under the Allen bolts to the cardboard so I have all the hardware in one place.

I heat the inner timing cover boss around the front crankshaft seal. The crankshaft nose bearing is inside the boss and heating the aluminum inner timing cover will expand the boss so I can pull the inner timing cover off the nose bearing.

After heating for about a minute or two, I wiggle the inner timing cover as I pull it off the crankshaft nose bearing.

Components Inside Inner Timing Cover

This diagram below shows the components inside the inner timing cover. The diagram is from a 1983 R100RS that has the same components behind the inner timing cover as the R80ST.

Remove Timing Chain, Chain Tensioner & Chain Slider (aka, Rubbing Block)

I showed how I do this on a previous build of a 1983 R100RS which has the same components as the 1983 R80ST. You can read about that here.

• 11 BMW 1983 R100RS Remove Timing Chain, Crankshaft Nose Bearing & Sprocket
  • Remove Timing Chain
  • Remove Chain Tensioner and Slider

Here are some pictures from the R80ST.

Remove Crankshaft Timing Chain Sprocket & Nose Bearing

I showed how I do this on a previous build of a 1983 R100RS which has the same components as the 1983 R80ST. You can read about that here.

• 11 BMW 1983 R100RS Remove Timing Chain, Crankshaft Nose Bearing & Sprocket
  • Remove Crankshaft Nose Bearing & Timing Chain Sprocket

Here are some pictures from the R80ST.

Install Crankshaft Timing Chain Sprocket & Nose Bearing

The 1983 R100RS uses the same components as the 1983 R80ST. I replaced the crankshaft sprocket and nose bearing. This document for the 1983 R100RS shows how I install the crankshaft sprocket & nose bearing.

• 11 BMW 1983 R100RS Install Crankshaft Sprocket, Nose Bearing, Timing Chain, Front Main Seal, Inner Timing Cover
  • Preparation For Crankshaft Sprocket and Nose Bearing Install
  • How To Assemble The Cycle Works Tool
  • Install Crankshaft Sprocket
  • Install Crankshaft Nose Bearing

Here are some pictures from the 1983 R80ST.

Install Timing Chain

The 1983 R100RS uses the same timing chain components as the 1983 R80ST. I replaced the timing chain, the chain tensioner arm, spring and piston, and the timing chain rubbing block. This document for the 1983 R100RS shows how I install the timing chain.

• 11 BMW 1983 R100RS Install Crankshaft Sprocket, Nose Bearing, Timing Chain, Front Main Seal, Inner Timing Cover
  • Install Timing Chain with Master Link

Here are some pictures from the 1983 R80ST.

Install Inner Timing Cover and Front Crankshaft Seal

The 1983 R100RS uses the same inner timing cover and front crankshaft seal as the 1983 R80ST. I replace the inner timing cover gasket and the two donut gaskets and the crankshaft front seal. This document for the 1983 R100RS shows how I install the inner timing cover and front crankshaft seal.

• 11 BMW 1983 R100RS Install Crankshaft Sprocket, Nose Bearing, Timing Chain, Front Main Seal, Inner Timing Cover
  • Replace Front Main Seal
  • Install Inner Timing Cover

Before I install the inner timing cover, I bead blast and paint the timing cover. You can read about how I do that work here.

• 51 BMW 1983 R80ST Repair, Refinish & Paint
  • Paint Inner Timing Cover

Here some pictures from the 1983 R80ST. These show how I clean the engine block and remove the inner timing cover gasket using a razor blade and 600 & 1000 grit wet/dry sandpaper to remove small bits of gasket stuck on the engine block, and the mating surface of the inner timing cover.

I also make sure I remove the blue shop towel I put in the hole of the engine block when I installed the timing chain.

I replace the front crankshaft seal. Using a 30 mm socket and hammer to remove the seal. I clean the bore with 600 wet/dry paper to remove any rubber bits of the seal before installing the new seal.

I apply engine assembly lube on the timing chain, crankshaft and camshaft timing sprockets and around the ball bearings of the nose bearing. This ensures the timing chain is lubricated during the first engine start so the parts are not damaged due to lack of lubrication.

I clean the engine block and the inner timing cover mating surface with alcohol wipes to remove any oil or grease so the inner timing cover gasket will seal to the block and cover with it’s heat activated glue. Then I put some oil on the outer race of the nose bearing so it will slide more easily into the boss of the inner timing cover.

I heat the inner timing cover in the oven at 250 F before putting it on. I use the Cycle Works tool to press the inner timing cover tightly against the engine block. Then I verify that the two donut gaskets that fit around the top timing cover bolts are correctly in place.

I torque the inner timing cover Allen bolts and nuts to 72 INCH-Lbs (NOT FOOT-LBS) in three stages; 30, 60 and 72 INCH-Lbs. Before I complete the final stage to 72 INCH-Lbs, I use my heat gun to heat boss around the nose bearing for 2 to 3 minutes to heat it and ensure the nose bearing is seated all the way in the boss.

Here is the final result.