How do I make the sled shift out higher? I have a comet primary and stock secondary. if I remember right I need more pretension in the secondary spring. There are not many springs available for this will other springs work. Or am I going at this the wrong way. I have purple spring -758 in the primary with n1 notched wieghts. It engages at 5500 but it seems to shift out to low. I'm hitting 9000-9200 top rpms. Should I throw more wieght at it? The belt seems to slip at top end also. Any suggestion are welcome. Thanks in advance.
Changing the shift out on a 79 SRX
- Thread starter Sanka
- Start date
YAMMIEGOD3:16
Active member
SHIFT RPM IS NOT TO LOW, WHY YOU THINK THAT. YOUR ENGAGEMENT IS SPOT ON, YOUR PEAK RPM IS SPOT ON. YOU POSTED YOU HAVE A STOCK MOTOR. WHY WOULD YOU WANT TO RUN IT ANY HIGHER THAN 9000. THATS PEAK POWER FOR A STOCK 79 SRX. 3:16 (yammie tony)Sanka said:
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is the tach rising from your engaement speed to 9000 then falling back and regain rpm after its going down the track?
Yes I believe it is? It pulls hard in the hole but then it appears to slow down from midrange to the finish. I was radared at 73 in 500' is this good? Just seems not to pull as hard on the top end. Could it be my 16 -31 gearing?
Thanx for the help. by the way this is on grass (I grass Drag It)
Thanx for the help. by the way this is on grass (I grass Drag It)
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YAMMIEGOD3:16
Active member
GEARING MAY BE CULPRIT. 16-31 PROBLEY EXPAINS 73 IN 500 WHICH REALLY AINT BAD. TAKE YOUR GEARING UP TO 17-31 , AND TRY IT. YOU HAVE A NICE SET-UP THERE. LET ME ASK YA, WHAT BELT YOU RUNNING. 3:16 (yammie tony)
YAMMIEGOD3:16
Active member
MAX 1106 IS GOOD, MIGHT WANT TO CONSIDER 1049 ( same lentgh as 1106 but slightly wider) OR ORIGINAL YAMAHA 8F2. SECONDARY SETING IS #3 POSITION AT 90 TWIST. SPRING IS YELLOW. NOW IF YOU INCREASE TWIST RPM WILL INCRESE. ALSO 16-31 GEARING IS 1.93 RATIO, TRY 17-31 1.82 RATIO. TELL YA THE TRUTH, I THINK YOU ARE OVER REVING THAT SLED SLIGHTLY. ACTUALL PEAK RPM FOR THAT SLED IS 8800 TO 9000 IF IN FACT YOUR MOTOR IS STOCK LIKE YOU SAY. 3:16 (yammie tony)
how can I bring the top rpm down? I have notched N1 arms. I need more weight in the arms right. What about the curvature on the arms? Do I need to go to a different arm a-25 comet arm? It turns 9000-9200. Its stock also. I'm running with out the power jets and airbox also?
YAMMIEGOD3:16
Active member
BECAREFUL RUNNING ON GRASS WITHOUT SOMETHING ON CARBS. I SUGGEST YOU RUN AIRBOX, BUT GUT IT. GREAT MOVE GETTING RID OF POWER JETS. I ALWAYS BLOCKED MINE ALSO. BEING AS CLOSE AS YOU ARE RPM WISE, YOU CAN TRY BACKING OFF SECONDARY TENSION SLIGHTLY, OR YES LIGHT,IN WEIGHTS UP. BEST WAY TO DO THAT IS WITH A BELT SANDER AND THEN YOU NEED A GRAM SCALE. I NEVER USED A-25 IN ANY OF MY SRX,s. I HAD GREAT LUCK WITH THE N-1, P-1, C s. 3:16 (yammie tony)
YAMMIEGOD3:16
Active member
DUDE, I RUN NEW STUFF NOW, I HAVE A 79 SRX THAT I BOUGHT NEW AND RACED IT TWENTY YEARS AGO. TODAY I USE IT FOR VINTAGE SHOWS ONLY. EVERYTHING HERE IS WHAT I RAN EXCEPT GEARING. 17-31 WORKED GREAT FOR ME. AND YOUR CORECT ABOUT WEIGHTS. 3:16 (yammie tony)
YAMMIEGOD3:16
Active member
PRETTY LOW. I THINK THATS KILLING YA. 3:16 (yammie tony)
opsled
Active member
Tony knows his $hi++ when it comes to dialing these old hot rods so if it won't go with his tips you have something else going on.
I only have one thought on it. Which Comet are you running? 102 or 108. If you have a 108 that could also be your troubles. It's a larger diameter clutch and if you run one with the stock secondary it might not be able to open far enough to allow the 108 to close causing belt slippage and a high rpm, fully shifted bog. It was a common problem with the early Vmax 540's when they were converted from a 102 to a 108 and I have seen the same problem on SRX 440's using a P-85 Polaris clutch which is the same diameter as a 108 comet. If you are running a 102 none of this applys.
Good Luck, opsled
I only have one thought on it. Which Comet are you running? 102 or 108. If you have a 108 that could also be your troubles. It's a larger diameter clutch and if you run one with the stock secondary it might not be able to open far enough to allow the 108 to close causing belt slippage and a high rpm, fully shifted bog. It was a common problem with the early Vmax 540's when they were converted from a 102 to a 108 and I have seen the same problem on SRX 440's using a P-85 Polaris clutch which is the same diameter as a 108 comet. If you are running a 102 none of this applys.
Good Luck, opsled