My really dumb engine question

[wes0778]

For a '98 RSTC, what is the firing order? Does each cylinder fire individually, or do two of them fire at the same time?

When I lug this thing, It sounds to me like a 2 cylinder rather than a 4.

At 65 and above it has a sound that to me sounds and feels(vibrates) like a V-twin.

I've never had one of these V4s before so I don't know what to expect.:confused24::confused24:

[GeorgeS]

Down shift! Open Throttle !!!--- Its NOT a Harley, Take note of where the Red Line is, 7,500 RPM.

[BuddyRich]

I don't even get outta 3rd sometimes until 75. Wind it out. Check your carb sync.

[Squeeze]

Firing Order is 1-3-2-4.

 

Let this thing rev, get a Tach and don't run it under 3500. These Motors actually love to run.

[V7Goose]

I don't know the firing order off-hand, but they do not fire together - I looked at the cam timing and firing pattern once, and the engine has a strange non-symmetrical overlap.

 

Lugging an engine is never good, but especially not on a short-stroke multi like this. Keep those revs up, especially when accelerating hard. The bike will run happily all day at 2,000 RPM, but if you are gonna lay on the throttle hard you need to be at least 3,000 or above. If your bike shakes at 65 MPH (it's running about 3,000 RPM in 5th gear there), you need to get the carbs synced.

Goose

[BigBoyinMS]

Hey Wes!

 

Left rear is '1'

Left front is '2'

Right rear is '3'

Right front is '4'

Firing order is 1,3,2,4

 

I 'think' it's a wasted spark ignition. Not sure on that.

 

I should have mentioned it the other day... never lug it. Keep the RPM's up. They like to rev. And I like to rev it! Well, maybe not that much. LoL

But it still shouldn't feel like a V twin.

Let me know if I can help with anything. Maybe I'll see you at the Cycle Expo Saturday.

[pegscraper]

Yes, it's a waste spark ignition. The plug fires every time the cylinder comes to TDC, even on the off cycle or the overlap phase. But the four cylinders still have their combustion strokes at four different times. The uneven firing pattern is due to the 70º V angle of the engine. One side of the pattern has a 20º overlap and the other side has a 20º gap. A 90º V engine could be completely even, but Honda somehow patented that angle for a V4 engine and no one else can use it. I don't know how Honda managed to do that.

 

His bike is a '98 Royal Star, not a 2nd gen Venture. Rev limit is 6000, not 7500. (The early Royal Stars are what is slower than a 1st gen. The 2nd gen Ventures are not.)

 

The early Royal Stars do not have a counterbalancer in the engine like the Ventures do and they are geared even higher than the 2nd gens are. The Venture engine may run happily all day at 2000 rpms, but this bike will not. It will pound and shake like crazy if you try to run along at 2000 rpm. It needs to be running at least 3500 rpms or higher before it will smooth out. This engine will still vibrate at 65 mph given any throttle at all, even if the carbs are in perfect sync. Fifth gear is so high in this bike you won't get away from that vibration under throttle until you get up around 75 or 80 mph.

 

Here are some suggested shift points to help you get used to this engine: 25, 45, 55, 60. That assumes moderate acceleration and a top speed of 60 mph. If your top speed will be higher, stretch them out a little more. Fourth gear in this bike is what fifth gear used to be in older bikes, and fifth gear is a ridiculously high overdrive at .75:1. Don't shift into fifth gear until you're all done accelerating and you've come to your final cruising road speed.

[V7Goose]

All great information from someone who knows that particular bike. I knew I should keep my yap shut about anything but the modern stuff! I'll try harder.

Goose

[BradT]

All great information from someone who knows that particular bike.

 

I knew I should keep my yap shut about anything but the modern stuff! I'll try harder.

Goose

 

Yes to first statement and :rotf:to the second.

 

Brad

[wes0778]

Lynn, thanks for the info. I may have been shifting too soon. Just for grins this afternoon, I ran it up against the rev limiter in 1st and 2nd. Cuts off @ 41 in 1st and 66 in 2nd. I ran out of road to go any faster, but am gonna try 3rd an 4th on I-20 this week end. We know it is limited to 112 in 5th.

Normally I just get her rolling before shifting to 2nd and in a residential area she will run happily along at 35 in 5th as long as I don't add much throttle. On the highway it will accelerate smoothly from 50 to 70 in 5th. (not at WOT, though, that takes 4th) As it eases through 60-65 I start to get a vibration that sounds and feel like one cylinder takes the bulk of the work. It begins to dimish somewhat around 80. That is as fast as I have run it so far. (too many highway patrol here around the capitol city.)

I'm about finished with my second tank with 1/2 a bottle of SeaFoam per tank. Can't say I can tell much difference. I don't know this bikes pedigree, so I'm gonna have a reputible independent shop balance the carbs Monday. I don't know if that will help. If autoxone has the spark plugs, I may change them. The bike starts, from cold, instantly with no choke. Even when the overnight temp got to 35F.

 

I cannot put the Barons on this week end :depressed:as our local stealership does not stock the bottom bolts. They also cannot tell me the size/pitch/length:headache:, so I will probably pull one of the floorboard bracket bolts and match it up (grade 8) from the parts dept. where I work.

 

Again, thanks for the info.

 

Walter

[wes0778]

Somebody :whistling:told me that my bike will blast through 90 in 3rd and the rev limiter won't rear it's ugly head.

The same person tells me that the vibration that appears at 60-65 mostally disapears around 85. Again, not that I would know first hand :whistling:

 

Walter

[autopilot]

Pegscraper, you never cease to amaze me with you knowledge about these old puppies. You confirmed for me that there isn't really anything wrong with my bike. I knew she was geared pretty tall, but I had no idea it was that tall. I also didn't know there were such substantial differences from our bikes to the newer ones