Interstate ICM

[Red Diamond]

For those who have made the switch, what have you gained or lost with the installation of the Interstate ICM on your Tourer or Standard?

[Challenger]

I took the ICM out of my 99 I/S and installed it in my 2000 Std for a couple of days just to try it, I could see no difference what so ever, But seat of pants dynos are unreliable though, I could tell no difference in starting, lugging it or hammering it. My neighbor and I went out and did a couple side by side runs with his stocker, Neck & neck just as before the swap. I did not check mileage so it could have helped with out me knowing it. I put it back in the I/S and decided not to spend the money for one for the Std. Just my experience and not scientific by any means.

[Red Diamond]

I really prefer the personal experience over the scientific one, good report, thanks.

[wizard -vrccds#125]

Did it to both of my bikes. More low end response and better MPG.         May just  be me, I do know of others that got the same when changed.

[Farther]

I changed both the carb springs and the ICM to the Interstate version and the only thing I am sure of is I used to have a slight surge at low speed/low rpm (25 mph in 5th) that seems to be gone now.

[JC]

IS ICM and springs in my 97 Tourer gave me a little more giddyup in the low end, and slightly better mpg when behaving myself at normal cruising speeds, otherwise no real difference. Not sure if I'd pay the money to do the ICM again, but the springs were cheap.

[MP]

I have an IS ECM in my 97 std.  Cannot say I saw much difference.

MP

[Tx Bohemian]

Did it on my '99 Standard and I've noticed a world of difference on the low end. I would say one of the best and easiest mods I've done. 10 mins.

Mileage did not change: 32-34 normal "Valkyrie" riding, 46-48 keeping it under 60 (back roads).

I do have a different timing wheel that was on the bike when I got it and the PO can't remember how much advance it is and I haven't looked yet.

[mario]

i have one on my standard that gives me a bit more off the line, it seems, but for me mileage is worse because it makes me want to twist the throttle even more.   

i'm taking it out and putting the standard back in. 

[Tx Bohemian]

i have one on my standard that gives me a bit more off the line, it seems, but for me mileage is worse because it makes me want to twist the throttle even more.   

Yeah, it does have that effect!!

i'm taking it out and putting the standard back in. 

I thought about doing this too after my first ride. 
Wife and I took a 100 mile trip and we had to be at a location at a certain time, in other words we had no time to waste.
We scooted down the road at least at 75ish, two up (both full sized people) and bucking a pretty good head wind.

When I filled up I got a whopping 25 MPG!!!

Although I like the extra boost this thing gave, it ran good enough for me with the original ICM, especially if this is the kinda mileage I'm going to start getting.

However under normal conditions my mileage is the same (32ish) as with the old ICM, but it sure is hard not to punch it on take off!!

[Farther]

I could be wrong but I believe that above 3000 rpm that the programing is the same for ignition advance on both the Standard and Interstate ICM.  So at highway speeds exceeding 65 mpg your fuel mileage will be the same no matter which ICM you have installed.  Under 3000 rpms I would think your fuel mileage would be better.  Someone correct me if I am wrong.

[98valk]

I could be wrong but I believe that above 3000 rpm that the programing is the same for ignition advance on both the Standard and Interstate ICM.  So at highway speeds exceeding 65 mpg your fuel mileage will be the same no matter which ICM you have installed.  Under 3000 rpms I would think your fuel mileage would be better.  Someone correct me if I am wrong.

here are the curves, at about 4200 rpms for the std/tourer the curve is then the same as the I/S icm. more advance 9 out of 10 times at cruise rpms aka high vacuum conditions will provide better mpg. if only the bike had the ICM setup the GL1500s have, which is vacuum controlled with 40 degrees of advance at cruise. This is one of the areas honda cheaped out on the bike.

http://timskelton.com/valkyrie/tech/trigger_wheel_plus_dyna3000.htm

[Tx Bohemian]

  So at highway speeds exceeding 65 mpg your fuel mileage will be the same no matter which ICM you have installed. 

You're probably right. 

In my case under the same conditions (the 75mph is being conservative) I probably would've gotten the same 25MPG with the old ICM, but it was sure a shock to my system when I realized I got such terrible mileage.

[PharmBoy]

Nothing more than a 4 degree wheel is recommended for the I/S, or at least I don't ever remember anyone recommending such...Jim

[valky1500]

The differences between the Interstate and Standard can be attributed to the ICM with a 5 degree advance in the timing between 2,000 - 3,000 rpm
New springs on the carb slides for quicker response and alternator that kicks in at 740 rpm instead of 950 rpm. 

[Tx Bohemian]

...and alternator that kicks in at 740 rpm instead of 950 rpm. 

Couple of questions on this:

Is that engine or alternator RPMs?

Does the Interstates idle at a lower RPM than a Standard?

[98valk]

The differences between the Interstate and Standard can be attributed to the ICM with a 5 degree advance in the timing between 2,000 - 3,000 rpm
New springs on the carb slides for quicker response and alternator that kicks in at 740 rpm instead of 950 rpm. 

I posted the link to the advance curves it is 2k to 4200 rpms where the I/S is better.
there is no difference btwn  the regulator in the alternators per the service manual. if true please provide the reference or are u stating the specs from a GL1500 GW alternator regulator which I believe is also the same as the valkyrie.
thanks

[valky1500]

I posted the link to the advance curves it is 2k to 4200 rpms where the I/S is better.
there is no difference btwn  the regulator in the alternators per the service manual. if true please provide the reference or are u stating the specs from a GL1500 GW alternator regulator which I believe is also the same as the valkyrie.
thanks

Because I do own both IS and Standard, and only from memory alone of reading it before, what I was referring to here was that Honda did advance the timing curve 5* in the Interstates somewhere between 2000 and 3000(?) RPM's by using the ICM and that doesn't include the 4* trigger wheel they also used for the mechanical advancement in the CF models that totals 9* advance over the other models.

I was also eluding to suspect that it is the ICM of the Interstate CF model that is responsible for the different charging between of the alternators of the other different models.

I forgot to mention that yes they are in fact two (2) different alternators being used here. The IS CF model alternator is (HITACHI LR140-722) and the other 2 model Valkyries'(OEM LR140-718A and LR140-718B, 31100-MZ0-005).

Thanks 

[Red Diamond]

Thanks for the many responses to my question. Having an I/S and a Tourer, I'll just switch the modules and see or try to feel if there is a difference. I do know that my Tourer feels like it has  a better power response than the I/S, but the I/S gets much better MPG (40 @ 70MPH indicated VS 32-34 for Tourer).

[valky1500]

The IS gets better gas mileage than the Standard when both were stock yes...

and because of the outputs of the different alternators the IS can and does support a lot more electrical gadgets such as radios, lights and heated clothing when compared to the other models.

thanks