New (to me) 1996 RS Dynatek

[sammydogs64]

So I just purchased a 1996 Royal Star Tour Classic. I love the bike, its so comfortable and balanced it has beautiful lines. It has aftermarket pipes, but was never jetted, plug check looks good, light brown. I was hoping to bump up the ~70hp and was thinking of the Dynatek module but read a one sentence statement that said I could advance the stator by 4 degrees. The 5700 rpm rev limiter should be addressed but I am looking to get the timing bumped for more performance.

 

What do you guys recommend Dynatek or timing advance and detailed instructions on the procedure for correctly advancing the timing would be great.

 

Thanks

[Freebird]

They are beautiful bikes and you will be very happy with it. The biggest problem you are facing in regards to performance though is that they don't get enough air. Yamaha went with looks instead of performance on those models and drastically reduced the air flow in order to hide the air filters. The first thing you need to do is increase the air in...that will for SURE require re-jetting also. The ignition modules are not going to help much at all if that is all you do.

 

There may be cheaper ways to go but Baron's offers a kit that will do the job.

 

http://www.baronscustom.com/catalog/display/254/index.html

[BigBoyinMS]

And for even more performance (significantly more from what I read) you can go to a set of 32mm carbs off of a 2nd Gen. It's a bigger job than most want to do though since it requires making a set of adapters. Pegscraper here on the forum would be the man to contact on that mod. His '96 has the carb swap, VMax cams and a multitude of goodies.

[sammydogs64]

So the timing advance and higher rev limiter on the dynatek doesn't add much? How about just replacing the air cleaner element? Getting at the mains of those four carbs seems like a FUN job.

 

One of the first thinhs I was planning on was shimming the neddles as the slides look really easy to get at.

 

I had a 2000 Honda Magna before this so I am familiar with the carbs on a V-4

[pegscraper]

The D3K won't get you anything real noticeable. The stock rev limit is low, but you can't raise it much without putting in heavier valve springs. And if you're going to do springs, you might as well do cams while you're in there.

 

The stator has nothing to do with ignition timing. You might be able to advance the rotor if you could find an offset key for the crankshaft. I did slot the mounting screws on the pickup coil and advanced the timing 4º that way. I used to have pictures of this, but my computer crashed some time back and they were lost. I didn't think it really gave me anything anyway.

 

Shimming needles and playing with jets won't get you anything either. These carbs are just not big enough to do the job. They are only 28mm. Correct me if I'm wrong here - your Magna would have been a 750 and had I think 32mm carbs on it? Yamaha should be slapped for putting 28mm carbs on a 1300cc engine. Even 32mm carbs are not big enough for a 1300, but they're all that will easily fit in this frame, and they are a huge improvement over stock. The engine really should have 35s or 36s on it. The 32mm carb swap information can be found here.

 

Bigger cams and carbs are the only ways to get any real gains out of this engine. Only then would I spend the money on the D3K to raise the rev limit and advance the spark timing. Fiddling around with other little things will simply waste your time and money and leave you disappointed in the results.

[sammydogs64]

The Magna I had, had four 34 mm CV carbs and was a 750 with 86 rwhp at 9000 rpm's, I used to beat up on VTX 1800's with stock exhaust. I am not looking to beat up on anyone anymore, I just like things to be optimized, I can't leave well enough alone.

 

The 5700 rpm rev limiter on the 96 RS seems a little sad, that motor should turn 7000 rpms with stock valve springs.

 

I know they were going directly against the HD Road King with this bike and its perfomance is better than the HD. Tops speed is rated at 101mph due to the rev limiter. Is there a throtle positions sensor that alters the igintion timing or is it directly related to rpm's?

 

I had a Kawasaki Prairie 650 that gained 5 rwhp just by adding a dynatek, its too bad the Royal Star does not show the same results.

 

So I guess the bottom line is there is no easy HP to be had, or am I wrong?

[pegscraper]

I was thinking of the mid '80s 700 Magnas that had 32mm carbs. So this one has 34mm carbs. An even better comparison. A 1300cc engine with 28mm carbs is not at all optimized.

 

Yamaha nailed this bike in looks. (Actually they patterned the Royal Star after the Indian rather than HD.) But on the performance end, they really boofed the pooch in a number of ways. The 28mm carbs are such a huge mismatch on a 1300 that there's just no way to increase the performance of this engine until some bigger carbs are put on. You can try other things, but the carbs are by far the biggest restriction and virtually no performance increase will be seen. The cams are small, the intake cam is even smaller then the exhaust, and the springs are very soft. Even Dyna themselves recommend no more than a 6500 rpm rev limit without heavier springs. Pathetic.

 

Spark timing is based both on rpm and throttle position via a TPS.

 

The other big mechanical mismatch on this bike is the gearing. It is way too high for any engine, and especially for one that likes to rev. Fourth gear in this bike is exactly the same as fifth gear in the 1st gens, and first gear feels like about what second gear ought to be. Fifth gear in this bike is so high that the engine can't pull it. Give it any gas at anything below 70 mph in fifth gear and it pounds and lugs and shakes. The engine is just not spinning fast enough. I never use fifth gear. Never. And I have no loss of gas mileage from when I used to.

 

The 32mm carb swap isn't that difficult. It just takes some fiddling. I can make the adapter plates and mill your intake boots if you want, or any machine shop can do it. VMX cams and springs, and 32mm carbs on this bike will get you an additional 30 rear wheel hp, or about a 50% increase. That is huge. Unfortunately, until the silly 28mm carbs are tossed out, no other tinkering is going to amount to anything.

[sammydogs64]

Thanks Pegscrapper, you were a ton of help.