Whats The Diff Srx 440


Everything but the name. Chassis, motor,pipes, carbs,skies,suspension,track, Seat,gas tank ,dash, all different ....Maybe the radiator and hoses & recoil same.
 
Last edited:
what made the 76 engine diff that made it faster than the 80 and what year did engine change
 
sick srx said:
what made the 76 engine diff that made it faster than the 80 and what year did engine change
Click to expand...


You may have already seen this but there is some good information about the History of the SRX in the link below. It may not spell out every detail of your question but when you begin comparing part numbers of the ignition systems with combustion chamber size and octane requirements and carburetor design and clutching requirements and comments from guys who actually owned and raced these sleds you can see the early SRX motors were very high strung race oriented sleds. By '78 with the larger CC cylinder head it becomes clear Yamaha was looking for a sled that would be more reliable in the hands of the average consumer.

There is lots of good info in this link and you have to read between the lines to some degree but it's pretty easy to see why and how the early SRX's were so much more powerful and faster than the sleds that replaced them.

Hope this helps.

History of the SRX
 
80 SRX WAS A MUSCLE / TRAIL SLED. FIRST YEAR OF OIL INJECTION AND BUTTERFLY CARBS. YOU COULD WALK IN TO A YAMAHA DEALER AND BUY ONE. THE 76 SRX WAS A RACE SLED AND YOU HAD TO HAVE A RACE RESUME TO GET ONE. BUILT FOR OVAL RACING, FOLK LORE HAS IT YAMAHA BUILT 1000 FOR RACING HERE IN THE STATES. 500/340, 500/440. 80 SRX WAS AROUND 75 HORSE AT 8800. 76 SRX 440 WAS 88 AT 9500. 3:16 (yammie tony)
 
YAMMIEGOD3:16 said:
80 SRX WAS A MUSCLE / TRAIL SLED. FIRST YEAR OF OIL INJECTION AND BUTTERFLY CARBS. YOU COULD WALK IN TO A YAMAHA DEALER AND BUY ONE. THE 76 SRX WAS A RACE SLED AND YOU HAD TO HAVE A RACE RESUME TO GET ONE. BUILT FOR OVAL RACING, FOLK LORE HAS IT YAMAHA BUILT 1000 FOR RACING HERE IN THE STATES. 500/340, 500/440. 80 SRX WAS AROUND 75 HORSE AT 8800. 76 SRX 440 WAS 88 AT 9500. 3:16 (yammie tony)
Click to expand...
can you change any parts from the 76-77 that made it faster onto the 80
 
sick srx said:
can you change any parts from the 76-77 that made it faster onto the 80
Click to expand...
....................................................well

yes and no with lots of work you could put the cylinders and head from them on the sled but you would also ruin them because you have to drill out the cylinder stud holes ...........but with a 80 ignition just not hot enough to do the job ..........about the only bolt on part would be the 76 pipes that is just about it ............

yamigod who spins a stock 76 at 9500 rpms ..........there best power is at 9-9200 anything more and you are wasting power the pipes where only designed to run at a max of 9200rpms .............we know we have more in ours yet but how about a 6.16 in 500 ft on grass with a bone stock 76 and all yamaha clutches yet
 
WHO SPINS A 76 AT 9500 ? APPARENTLY YAMAHA. SHIFT RPM ON 440 WAS 9500 , RIGHT OUT OF MY SERVICE MANUAL. DON,T KNOW NUTZ. 3;16 (yammie tony)
 
never read the manual ...was always told they dynoed at 9-9200-----and from the info i have gathered over the years the manuals where on the high side ........most likey due to the purpose build of the sled for oval racing and needing the over rev to help backshift ..............same thing goes for the gpx's ........i have dynoed my stockers and they do not make the power where the manual says to run them
 
LIKE YOU, I HAD THEM ALL AND RACED THEM ALL. FROM WHEN THEY WERE NEW UP TO 1995 WHEN THEY ALL WENT BECAUSE I BOUGHT A BRAND NEW VMAX 4. I BUILT A 78 SRX RIGHT TO 76 SRX SPEC FOR DRAG RACING WITH BRUCE FROM PSI. WHO WAS AAEN PERFORMANCE PORT MAN AT THAT TIME. THIS SLED WAS PORTED EXACTLY TO STOCK 76 SPEC, 8G9 CYLS, .40 MM CARBS, 76 AIR BOX , 78 8G9 HEADS CUT TO 76 SPEC, AND OF COARSE 76 PIPES. SLED FLEW, BIG CHEATER SLED. PEAK RPM WAS AT 9500. WICKED FAST. MY POINT, WHAT WORKS FOR YOU, MIGHT NOT WORK FOR SOMEBODY ELSE. 3:16 (yammie tony)
 
sick srx said:
what made the 76 engine diff that made it faster than the 80 and what year did engine change
Click to expand...

Heads and carbs. Motors same otherwise.
 
dynofun said:
Heads and carbs. Motors same otherwise.
Click to expand...
...and cylinders, pipes, ignition, crank and case. Then in 1977 everything was changed over again putting out even more power.
 
yamaton said:
...and cylinders, pipes, ignition, crank and case. Then in 1977 everything was changed over again putting out even more power.
Click to expand...

Reread his question. He asked what was different about the 76 motor that made it faster than the 80. The only performance difference is the heads and carbs. Ignition performs the same and the porting is identicle except for the intake size which is the reference to the carbs...

Open the intake of the 80, put on 76 carbs, heads and pipes and it will run the same as a 76.
 
dynofun said:
Reread his question. He asked what was different about the 76 motor that made it faster than the 80. The only performance difference is the heads and carbs. Ignition performs the same and the porting is identicle except for the intake size which is the reference to the carbs...

Open the intake of the 80, put on 76 carbs, heads and pipes and it will run the same as a 76.
Click to expand...
He did ask that but imo calling them same otherwise suggest that they are just that. Would agree on same powerwise.
 
i asked about the diff to see what could be done to up the power of the 80 to that of the 76or 77
 
sick srx said:
i asked about the diff to see what could be done to up the power of the 80 to that of the 76or 77
Click to expand...

Well I told you what it takes to bring it up to 76 level. If you want 77 power the only thing more you need to do is port it the same and get the same pipes.


:sled2:
 
You must log in or register to reply here.


Back
Top