The Best "Sachs" I've Ever Had...

Well, maybe not, but you don't have to send it flowers first.

My 79 Sachs Prima-G3, 505 engine, and I go back quite a ways. Several months ago, I lost my main seal in the engine and am now in the process of repair. The engine is off but I can't seem to figure out how to completely crack the case. All of the bottom bolts are out and it doesn't seem to want to seperate. Have I missed something somewhere?

Also, who's best for Sachs parts these days?

Re: The Best "Sachs" I've Ever Had...

Jake Van Order /

without a doubt, it's . although the site is in german, you can use altavista's translator to read the page in english. good luck, I'm interested in cracking my sachs case too, so I'll be reading this thread.


Re: The Best "Sachs" I've Ever Had...

Thanks for the TIP jake. Visited the German Sachs site that you mentioned for parts and it is unbelievably good! Must have everything and anything that one needs. I'll post on my 505 breakdown and rebuild as I go along. Thanks again.

Re: The Best "Sachs" I've Ever Had...

Matt Wilson /

Jake and Denis

To seperate the transmission case you need to remove all of the bolts that you can see, and 3 small screws underneath the flywheel cover.

The screws may be tight...

Mbartell explained this to me in an earlier thread about 2 weeks ago. Also while you have it open, I recomend that you replace the rubber o rings and seal the two halves to prevent the trans fluid from leaking, like mine did.

Here are some pics of my transmission open and one that shows the correct clutch assembly

<IMG src=""> ;

<IMG src=" trans case open.jpg">

<IMG src=" trans case open5.jpg">

Also the has an exploded picture of the clutch.


Re: The Best &quot;Sachs&quot; I've Ever Had...

Jeese, you beat me to it Matt. I guess I'll have to check on weekends now too.

It dosn't look like yours is leaking, anymore, so that's good.

When you re- assemble your motor, use thread-lock on the screws under the flywheel, because they will get loose and make your motor jam. I also like replacing the phillips - head screws with allen head ones, and new lock washers.

Handy Bikes is the best sourse for sachs parts. They don't have much of a web-site, but call and they will know what you need.

Re: The Best &quot;Sachs&quot; I've Ever Had...

Thanks for your help Matt Wilson...

Are you completely re-assembled and on the road?

Re: The Best &quot;Sachs&quot; I've Ever Had...

Thanksfor your help also Mbartell...

Have you ever decarbonized a piston head? If so, what's the best way to do it?

Re: The Best &quot;Sachs&quot; I've Ever Had...

Well, with the Sachs the head and the cylinder are one piece, and you can't really scrape it with anything. I remove the head/ cylinder, put and old spark plug in it, and use a solvent to dissolve any deposits. I use ford engine cleaner part #FMC PM3. It's available at most parts counters, and it comes either pourable or spray.

When re-assembling you case, use automatic transmission sealer on the mounting surfaces fo the case. Silicone dosen't hold up too well. It's Loctite #51813 Gasket Eliminator 518 sealant. I use just enough to coat the mating surfaces.

About the only other advice I give on the Sachs is make sure your decompression valve is set up correctly.

Search for sachs decompression, on this site and see if you can find the picture I put up here months and months ago.

Re: The Best &quot;Sachs&quot; I've Ever Had...

Re: The Best &quot;Sachs&quot; I've Ever Had...

Matt Wilson /

My sachs is all done, and just awaiting pison rings, a new base gasket, and that oild fillter plug. It should arrive either today or tomorrow from handy bikes.

I'm hoping that it will be leak free, but I haven't filled it up with fluid yet....It damn well better be!

I'll post when I get the parts in and let you know how well it works.

Also take a look inside your exhaust port. Mine had some sloppy welds and a very hard carbon deposits. I had to use a dremel to clean and smooth it out


Thanks Mbartell...

Will move forward with your rcommendations.

Matt Wilson...

With your exhaust, you may want to try a complete clean-out, since you have it off the ped. I had a welding shop take a torch to the inside of my exhaust, which burnt out ALOT of the mineral buildup. The welding shop guy said that he had an amazing amount of smoke that came out of the pipe when he torched it. He also said that the smoke stunk to high-heaven and trashed the place for about five minutes.

The only caution would be to torch the exhaust a little at a time, to avoid a meltdown of the exhaust.

When re-assembled, there was a niticeable increae in performance.

Maybe Mbartell or Fred have a little to say on this subject.

Re: The Best &quot;Sachs&quot; I've Ever Had...

Matt Watson,

How's the reassembly of the Sachs 505 going. Have you run into any problelms?

Re: The Best &quot;Sachs&quot; I've Ever Had...

Matt Watson,

How's the reassembly of the Sachs 505 going. Have you run into any problems?

Re: The Best &quot;Sachs&quot; I've Ever Had...

Matt Wilson /

It is completely reassembled still just waiting for the rings.

I talked to BJ at handy bikes and he sent the rings this tuesday because he took a week vacation. I will post with pictures when the rings come.

Maybe today?


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