450 guys - engine speed question

[spwalker09]

'83 GS450L, mechanically stock (gearing, wheels, etc.)

I'm just starting to get a feel for the bike and I'm curious. I always thought my tach was off, so I just wanted to double check how off my tach is before I wind up the engine and torch it.

At 50 mph in top gear, I'm doing an indicated 3000 rpm. The speedo is pretty accurate since I went by one of those signs that tells you how fast you're going and I was going within 1 mph of what was indicated by my speedo vs. the sign. I did some basic calcs using the info from my Haynes manual, and it seems that from the calcs, 3000 rpm should correspond to 494 rpm at the rear wheel, or half a mile per minute, or 30 mph.

I'm wondering if any of the 450 guys can give me any practical advice as to what engine speeds to expect at moderate cruising speeds (50 mph is a good baseline), so I can keep track of, and maybe ultimately fix, my tachometer.

Thanks!

 

[Charlie G]

I'll try to remember to take it out for a spin and see what the tach reads at 50mph. I may not get to it till Sunday, as I have an all day wedding to go to tomarrow.

cg

 

[chuck c]

I'll do it too, but I think 3000 at 50 is about right. Mine is an 80 L, are they all geared the same?

 

[spwalker09]

OK thanks. I really don't have a feel for these engines, and it worries me that the wind noise at 50-60 mph is louder than the engine, so w/ what I think is a non-working tach kinda scares me when I wanna downshift and get on it since theres no rev limiter. Mind you I wouldnt be doing that at 50 or 60, but definitely pulling away from stop signs on these rural roads.

According to my Haynes manual I believe they're all the same? I'd have to double check...

I think it might be not reading correctly b/c at idle, it reads nothing, and reads at ~1-1.5k when I launch it, and I'm definitely not launching it at that engine speed

 

[bgmart450]

I'll do it too, but I think 3000 at 50 is about right. Mine is an 80 L, are they all geared the same?

I think so, but one of the other factors would be sprocket sizes. Being a 450, you'll probably get less of a variation/choice, but even one tooth one way or the other will make a difference.

 

[chuck c]

I'll do it too, but I think 3000 at 50 is about right. Mine is an 80 L, are they all geared the same?

I was wrong. Mine runs 4200 at 50 in 6th.

 

[spwalker09]

I was wrong. Mine runs 4200 at 50 in 6th.

that probably sounds about right to me. At idle, my tach is just barely off the peg, meaning its probably off by a grand or so.

Anyone know how to adjust an '83+ tachometer. I tried to pull off the pointer, but I was afraid I was gonna break something (it was not coming off very easily)

Thanks!