Sachs 505a Performance

First of all and before anyone says it, yes, i have used the search, for days and hours.

Ive read everything i can find from Will and his knowledge of Sachs and Ron and all his "wisdom" of jetting.

Ive read posts from 2006 while laying next to my gf in bed, crying wondering why im not paying attention to her and if the last few years of our relationship were worth it.

I have a 505a with:

No airleaks

Compression is good

Bolted off decomp

19 BTCD

26mm Header Copper sealed Jammy slip on

15 Bing with a Puch Hi flo

75 jet (barely four strokes if rarely),

2.17 At,

2 band needle at the 2nd richest position.

10-42 gearing

Shinko sr241s (extra beef)

Taillight does not get brighter when I hit the Brakes, I get pops when i switch the gaia? control sometimes. Dim headlight. Could this be the problem?

Hits a quick and constant 24,

I feel like i could get more RPM but its hitting a wall.

Is there any tips anyone can give me to get this damn thing up to 30?!?!

Ive spent about 350 already and ive gotten maybe 2-3 mile increase.

Re: Sachs 505a Performance

shitty pipe, low gears, main jet too big would be my guesses.

i'd try dropping the main jet first, see if it runs better, then gears, then if you still can't get it to sing try a better pipe.

Re: Sachs 505a Performance

> Graham Motzing Wrote:

> -------------------------------------------------------

> shitty pipe, low gears, main jet too big would be my guesses.

>

> i'd try dropping the main jet first, see if it runs better, then gears,

> then if you still can't get it to sing try a better pipe.

Ive ran a 66-75 anything below 75 feels like its struggling, reading threads here folks always mention mid 70s for a 15 Bing.

Yeah the pipe is not doing what i expected it to do.

I was thinking about regearing but I like the torque, I guess i could get a new 11 front and bump it up.

Re: Sachs 505a Performance

yea that gearing sucks, go taller, bigger front smaller rear. by a lot, like 12/34 or 10/28. Also double check that decomp plug. on the pipe check that it's lined right up at the end of the header, the header's not protruding into the chamber and limiting a good back pulse.

the taillight engine popping issue brake thing might be that brakelight=ignition ground issue, i'd just ground the blue/black wire directly from the engine and see if that improves.

and that jet's too big. 75 on stock implies somethings missing, maybe there is an airleak you're missing, maybe the decomp is blowing by or something in the carb's not flowing right I dunno but 75's like where i'd expect it to run on a kit or monster porting, not a jammy pipe w 15 bing.

Re: Sachs 505a Performance

> Born to be WillD Wrote:

> -------------------------------------------------------

> yea that gearing sucks, go taller, bigger front smaller rear. by a lot,

> like 12/34 or 10/28. Also double check that decomp plug. on the pipe

> check that it's lined right up at the end of the header, the header's

> not protruding into the chamber and limiting a good back pulse.

>

> the taillight engine popping issue brake thing might be that

> brakelight=ignition ground issue, i'd just ground the blue/black wire

> directly from the engine and see if that improves.

>

> and that jet's too big. 75 on stock implies somethings missing, maybe

> there is an airleak you're missing, maybe the decomp is blowing by or

> something in the carb's not flowing right I dunno but 75's like where

> i'd expect it to run on a kit or monster porting, not a jammy pipe w 15

> bing.

Ok cool, thanks man, ill start double checking for leaks, yeah I ordered an 11 front sprocket cause i still want that low end pull.

So on the header, i have a bigger one from a Westlake, 26 instead of the stock 22mm, there is a section that tapers after a bit from where the slip on attaches down a millimeter or so, that part goes into the Jam about 5 inches, should i chop it? i know thatll increase my rpm but wont it kill the low end?

Just re did all the electrical according to the Repair Manual.

And as far as the jets Ill keep downjetting, only thing is when i tried a recommended 65, it was sloooooooow. so i guess the sweet spot is in the middle somewhere. The needle is perfect, takes off strong, just tops out at WOT at like 24-25

I went as far as ordering lighter IRC Zaps to replace my sr241s in search of a few mphs.

Thanks man

Re: Sachs 505a Performance

plug your decomp, thats the poppin noise. my 505a does 35.

20171102_145151.jpg

Re: Sachs 505a Performance

line it up off the bike, so the header ends at the the chamber, just leave enough to clamp. if you don't wanna shorten the header, just move the chamber back and rearrange the mounts.

Re: Sachs 505a Performance

♣Slew Foot♣ /

I think that because you switched to a Bing the old one was the square one and it was made for the back Scavenging of the Sachs 505 1A it required a low-flow air filter so that it actually had to suck to work really good it would use the airbox like a boost bottle when it was at wide open throttle top speed it would supercharge the mixture the original Square Bing only took a 54 jet but you can modify it so that you could run an 85 with kit motor

Re: Sachs 505a Performance

hmm Ive never heard of that but it could be!

Well i got down to a 71 MJ, it sounds like its struggling a little up top, but with a 72, it seems to run well and only 4 strokes when Im WOT for a long time.

Changed needles to to a 1 band, seems to be thinner and cleaned up the lower end a little.

Also i checked everywhere for leaks and didnt find one.

Might I add that im also at 950' elevation, North hot Texas

Adding an 11 tooth sprocket and 24 slide today.

Thanks for the input!

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