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99 VS800 Compression

Posted: Wed Sep 08, 2021 10:07 am
by HellerCole_3
Hi everyone, thanks for having me in your forum.

I have a 1999 VS800 that I've owned since 2007 (bought with 12500). It now has 48250 on it and has never given me major problems. It's starting to use some oil and I'm wondering if it's on the edge of needing a rebuild. I checked the compression and it is showing 150 in the rear cylinder 165 in the front. Plugs look good, valves aren't noisy, and it doesn't smoke in any way (startup or otherwise). I've noticed that since I moved back to Socal and am trying to keep up with traffic at 75-80 the oil consumption is much worse than if I keep it below 70. Given the mileage on the motor do you think 150/165 is good? I'm wondering if anyone has any experience with just how low these motors can get for compression before it's a liability on the road...Thanks!

Re: 99 VS800 Compression

Posted: Wed Sep 08, 2021 12:49 pm
by navigator
Starting to use oil, how much?

My experience:
I have an 800 with 106K on it, another with 98K.
They both use about a quart of oil every 3000-4000 miles, at which point, I change it.
I would not consider a rebuild at 48K.
They will use more oil at 75-80 than when below 70mph.
150/165 seems reasonable.
Be sure to take compression readings at WOT.

You say the valves are not noisy, they should tick.
The 800 has solid lifters, not hydraulic.
A valve adjustment may help reduce oil consumption.

Re: 99 VS800 Compression

Posted: Wed Sep 08, 2021 1:36 pm
by HellerCole_3
Thanks for the reply Navigator. I'm monitoring the oil level much more closely now so I can give a detailed answer as time goes on, but I changed the oil in March at 45320 and have already put in a quart (current odo is 48251). So in 6 months and almost exactly 3000 miles I've used a quart. I've never touched the valves thus far, not really sure what exactly they should sound like but the bike doesn't perform or sound any different from when I bought it 14 years ago (one the reasons I've never parted ways with it). It looks like trying to keep up with these speedy drivers in San Diego is what's causing the sudden uptick in consumption. I did have the throttle all the way open for the test, thanks. Well maybe I don't have to get rid of it after all (if using about a quart every 3K is somewhat normal -- anyone else have thoughts on this?)! Now if only I could track down some forward controls for this thing...

Re: 99 VS800 Compression

Posted: Wed Sep 08, 2021 5:17 pm
by FallenAngel
When doing a compression test
The bike should be a little warm if possible
Do a dry test first
Do Not put Oil in the in the cylinders
Then a wet test
A couple squirts of oil in each cylinder

If the compression is noticeable higher after the wet test then your looking at a ring job(Or Rebuild)

150/165
My 87 1400 is 160 frnt 170 rear and Im thinking of tearing it down this winter Or maybe next winter or the winter after that

Re: 99 VS800 Compression

Posted: Wed Sep 08, 2021 7:36 pm
by Lechy
Valve stem seals.

Re: 99 VS800 Compression

Posted: Wed Sep 08, 2021 8:19 pm
by hillsy
150psi would seem OK to me but the manual says rebuild.

Also note the compression test procedure....


Image

Re: 99 VS800 Compression

Posted: Wed Sep 08, 2021 8:26 pm
by HellerCole_3
Thanks for the additional replies. Wouldn't valve stem seals create some smoke at startup? I conducted the compression test per the manual, warmed up, WOT, etc. I think I'll accept that 150/165 ain't that great, but it's not bad either. It still runs great so I'll just keep chuggin along for now. Thank you for again for all the input, nice to know that something isn't really wrong with the consumption I'm experiencing. I will try to remember to post an update after I've logged another 3K miles without putting it over 70 mph (much).

Re: 99 VS800 Compression

Posted: Wed Sep 08, 2021 8:52 pm
by hillsy
HellerCole_3 wrote:
Wed Sep 08, 2021 8:26 pm
Thanks for the additional replies. Wouldn't valve stem seals create some smoke at startup? I conducted the compression test per the manual, warmed up, WOT, etc. I think I'll accept that 150/165 ain't that great, but it's not bad either. It still runs great so I'll just keep chuggin along for now. Thank you for again for all the input, nice to know that something isn't really wrong with the consumption I'm experiencing. I will try to remember to post an update after I've logged another 3K miles without putting it over 70 mph (much).
If I remember correctly the Honda CBR1000rr Fireblade from around 2008 had a lot of owners concerned as they would often burn a quart or two of oil every 1000 miles. Apparently Honda said this was "OK / normal" :dunno:

Point being as long as you are keeping an eye on the level, using oil is not the end of the world.

Re: 99 VS800 Compression

Posted: Wed Sep 08, 2021 9:05 pm
by Lechy
Poor man's check for worn rings and bores is to run a finger around the inside of the exhaust tips and see if the residue is oily.

Re: 99 VS800 Compression

Posted: Wed Sep 08, 2021 9:07 pm
by FallenAngel
HellerCole_3 wrote:
Wed Sep 08, 2021 8:26 pm
Thanks for the additional replies. Wouldn't valve stem seals create some smoke at startup?
Yes you may have some smoke at start up with bad Valve seals unless you running synthetic oil then you may have a wet pipe depending on how bad the seals are.

I wouldn't worry to much as everyone has said so far Ride it and keep an eye on the oil

Re: 99 VS800 Compression

Posted: Wed Sep 08, 2021 9:15 pm
by Herb
Bad valve seals will also cause smoke after idling, like when accelerating after sitting at a light.

Re: 99 VS800 Compression

Posted: Thu Sep 09, 2021 8:40 am
by navigator
Out of tolerance valve adjustment is mentioned many times....Just sayin' :wink:

Re: 99 VS800 Compression

Posted: Thu Sep 09, 2021 2:43 pm
by hillsy
navigator wrote:
Thu Sep 09, 2021 8:40 am
Out of tolerance valve adjustment is mentioned many times....Just sayin' :wink:
Yeah fair call - I saw he said he hadnt touched them but didn't notice the mileage.

Wet v dry compression test should indicate if there's leaks at the valves or past the rings though.

Re: 99 VS800 Compression

Posted: Thu Sep 09, 2021 3:48 pm
by Herb
navigator wrote:
Thu Sep 09, 2021 8:40 am
Out of tolerance valve adjustment is mentioned many times....Just sayin' :wink:
too tight will also lower compression

Re: 99 VS800 Compression

Posted: Thu Sep 09, 2021 4:30 pm
by navigator
Herb wrote:
Thu Sep 09, 2021 3:48 pm
navigator wrote:
Thu Sep 09, 2021 8:40 am
Out of tolerance valve adjustment is mentioned many times....Just sayin' :wink:
too tight will also lower compression
Precisely what I am saying.

Re: 99 VS800 Compression

Posted: Thu Sep 09, 2021 4:53 pm
by Herb
navigator wrote:
Thu Sep 09, 2021 4:30 pm
Herb wrote:
Thu Sep 09, 2021 3:48 pm
navigator wrote:
Thu Sep 09, 2021 8:40 am
Out of tolerance valve adjustment is mentioned many times....Just sayin' :wink:
too tight will also lower compression
Precisely what I am saying.
You are absolutely correct.