rev limits?

[Bill_Rockoff]

Maybe the OP would be interested in a Bimota YB8?  Neat bikes (like XJRs) and the Bimota owner/seller would probably get on well with the OP.  (Who, it should be noted, seems to be as comfortable and familiar with how vaginas work as he is about how motorcycles work.)

I'm pretty sure FJs, all years, have an electronic rev limiter, and I can't imagine they took this feature out of later-model motorcycles using the same engine.  Can't remember if mine was at 10,400 or 11,400 (10,400 sounds right) but I know I've hit it more than once in lower gears.  Not focusing on the tach reading at the time (obviously!) so I can't be positive.  I'll try it on my way out of town tomorrow and let you know.

I found my dyno sheet the other day, I'll scan it and post it after I get back from the ECFR.  Mine was in "MPH" in 4th so I had to estimate rpm from that (and calculate torque from that)  but IIRC it was a pretty flat torque curve peaking at 7,000 and a power peak of 103 hp at 8,500, still nearly 100 hp at both 8,000 and 9,000 rpm, and off to about 90 hp at 9,500 rpm. 

[racerrad8]

Looking at the wiring diagram suggests that this is indeed the rev limiter.

I am going to have to disagree on this one...

If that was the case and the tach itself was the rev limiter, how do you explain the rev limiter working on this and 1000's of other just like them?


If a tach is used it is an Autometer or other aftermarket unit.

Here is a photo of the back side of Skymasters 90 tach, I cant see any points anywhere. He does mention the trim pot for adjustment.

Oh, and here's another one for you. The tachometer on these FJ's can be calibrated. Mark and I are both running the same gearing and tires, but our tachometers are mismatched by about 500RPM. I hooked up an external tack and found mine was reading about 380RPM high.  There's a  trim pot on the back of the tach that you can adjust to change the displayed RPM.  Unfortunately I turned it to the left which had the opposite effect and further raised the displayed RPM. I'll fix it when I go back into it... (But just FYI, Left raises displayed RPM, right lowers it.)

It would be interesting to determine what the points you observed did.

The advertised rate of the electronic rev limiter has been 10,500 since I have been involved with the FJ power plant. I will say there is some variation in boxes, we have had some limit at 9800 and some that reach 11,000, but the majority are all right around 10,500.

Randy - RPM

[Firehawk068]

If it takes it cue from the tacho, as was suggested earlier, it won't matter whether it's accurate or not.
Noel

My meter has an inductive pickup that I can clamp over one of the spark plug wires, and will read rpm's from that...................I'll use it to compare it to my FJ tach at various rpm's..............

[Burns]

"It's funny when one examines the human condition, or at least it makes one think, if the actual (universal, absolute) truth, matters at all.  And to me it does!  Actually, it's all that matters, to me, at least!"



Faith in an Understandable Universe is hubris.

[JoBrCo]

Oh and did I mention..., Vegemite tastes like crap!        


JoBrCo

You lookin to start another argument? Vegemite forever!! Yummo,  
I only just read this thread today and had a strong feeling it was going to take a turn for the worse. Our mate from the other side of Australia obviously didn't like friendly advice which seemed to somehow insult his expertise. Anyway, his loss. The things he really could have learned if he stuck around.............

Actually just a joke for Rib, that has yet to post again, nothing more, nothing less!  It's how I top off all the positives, i.e. with a joking challenge of no real consequence, a sidebar to sidestep, if you will, to change the subject to something nobody really cares about. Oops scratch that!  Vegemite argument, sheesh!  

FJ Forever!   

JoBrCo

[JoBrCo]

Actually I've busted red line on several occasions, i.e., missed a gear, when down shifting so as to place her in her sweet spot, for rocket like acceleration.   Of course it scared the crap out of me, I didn't want to "blow it" further and finally!

FJ Forever!   

JoBrCo


P.S. the Vegemite thing was just for the sake of Rib's (Noel's) response, I figured he'd understand, knowing I was just "ribbing" him. Funny that it almost started a riot! 

[CanDman]

Vegemite is actually a yeast extract, and is very tasty. On hot buttered toast in the morning, on a sandwich with sliced tomato, on buttered crisp bread with a cup of coffee, love it. CanDman had a bit of it when he stayed with us earlier this year, and even though he put on a brave face, I know he won't be having it again.  

Having said that, even my family only very thinly scrape it onto bread etc, as they say its too strong. Me, I lather it on,  

https://www.vegemite.com.au/en-AU/FAQ.aspx

Errrr, anyway, something about revs was mentioned......  In fact, I have no idea what the FJ revs to as I have never wound it up that far, lol.

you mean this face........




mmmmmmmm beef broth paiste........yum...no worries Ray...when I return, I will eat it again with you.........along with some CanDman homemade Canadian pancakes

[Bones]

The advertised rate of the electronic rev limiter has been 10,500 since I have been involved with the FJ power plant. I will say there is some variation in boxes, we have had some limit at 9800 and some that reach 11,000, but the majority are all right around 10,500.

Randy - RPM


What does the engine do when it's hits the limiter Randy, does it stutter like modern bikes or does it just kill it till the revs drop.         

                                                         Tony.

[racerrad8]

What does the engine do when it's hits the limiter Randy, does it stutter like modern bikes or does it just kill it till the revs drop.         

                                                         Tony.

Well, I am not sure how to explain it and since I have never really ridden a modern bike I cant answer. The engine does not shut off, but goes into almost a mis-fire regulating the engine speed.  You can hold it on the rev limiter, but the engine losses so much power you automatically let off.

So, I guess it is more like a stutter.

Randy - RPM

[novaraptor]

Just read this thread today, not before, because I wasn't really interested in rev limiting, since I'm not interested in pushing things up there. Finally had to read it because there were so many pages to it..
I had a friend several years ago that would ask me questions about the way things worked, and, no matter what the answer was, would look at me and say "No. That can't be right.." So I would tell him to go look it up. And the next week, the play repeated it self.. Some people are just wired that way. If they don't know the answer, you can't possible know it, either. Been a fun post set. What have I learned? Well, Vegemite tastes like shit. "No. That can't be right..." Got to go get me some and see what I'm missing.

[FJmonkey]

Vegemite tastes like shit. "No. That can't be right..." Got to go get me some and see what I'm missing.

I can bring you a sample.... 

[Firehawk068]

Mark, your profile pic cracks me up everytime I see a post from you..................

[fj1289]

Well that explains why I can't PM Kurt now -- oh well, not a loss.  He was a royal PITA to try to work out shipping the sprocket

[Earl Svorks]

To see the bits in question, you need to look between the back of the tach face and the front of the white plastic housing. At first glance it could be taken for a return spring, but I think it's too light to be one.
As to why the cars do not seem to be affected , ummm, I don't know.
I'll post a pic of the tach I have if you don't find it on yours,

[Burns]

do the cars use the stock yam ignition?