Will a 2000 engine fit in a 1999 frame? Thanks.

I'm sure it could be done, it won't be a simple drop in job. Why not get a whole 2000?

I did a compression test on my engine and only came up with 160 lbs on all cylinder. Seemed kind of low. I'm just weighing my options in whether to pull the head because its probably valves or just finding another engine. Parts can get real expensive!

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><table border="0" width="90%" bgcolor="#6A7FB8" cellspacing="1" cellpadding="0"><tr><td width="100%"><table border="0" width="100%" cellspacing="0" cellpadding="2"><tr><td width="100%" bgcolor="#2f2f4f">Originally posted by speeder:
I did a compression test on my engine and only came up with 160 lbs on all cylinder. Seemed kind of low. I'm just weighing my options in whether to pull the head because its probably valves or just finding another engine. Parts can get real expensive!</td></tr></table></td></tr></table></BLOCKQUOTE>How many miles? Ever done a valve adjustment?

If you want to find out if it is your rings, do a compression test, then put about a table spoon of motor oil in the spark plug hole. turn the motor over a few times. then do your test again. If it is the rings, the oil will help to seal it and your reading should go up.

John

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><table border="0" width="90%" bgcolor="#6A7FB8" cellspacing="1" cellpadding="0"><tr><td width="100%"><table border="0" width="100%" cellspacing="0" cellpadding="2"><tr><td width="100%" bgcolor="#2f2f4f">Originally posted by speeder:
I did a compression test on my engine and only came up with 160 lbs on all cylinder. Seemed kind of low. I'm just weighing my options in whether to pull the head because its probably valves or just finding another engine. Parts can get real expensive!</td></tr></table></td></tr></table></BLOCKQUOTE>with compression tests, consistency across the cylinders is more important than the actual numbers.

if the numbers are the same or very close across all of the cylinders, i'd be more inclined to think that something else (like a weak battery) is affecting the actual numbers, rather than the compression across the cylinders actually being all equally low.

you might want to try the test again with another battery before you go through the trouble of ripping the head off in search of a problem that may not be there.

p.s. you DID do the compression test with the engine warm, and the throttle at wfo, right?

[ 04-03-2002, 08:09 AM: Message edited by: jeff ]

I agree with the above. Additionally, if it were my bike I'd tune it up and dyno it for $50, see if it still runs strong, that will give a cheap, easy final verdict. The magazine bikes made about 115 peak hp and 56 ft lbs (non-californicated) on a DynoJet dyno. Anything over 110hp and its a runner, don't worry about it. I'd replace the engine with a low miles used one before I went to the trouble of head work. Just my 2 cents

Thanks Sleaford I appreciate that. I was thinking of doing that as one of my options. I put a pcII on it and I'm sure the local shop could tune it up and dyno it.

Dont stress on your 160... It is normal... My friends 99 750 with just over 8000 miles got about the same numbers... When I was at 30K miles, I had about 122 (that was the best, the worst was 120), and the bike still ran GREAT! Just lacked a bit in the mid range.

I dont know what mine is after the rebuild ( I havent checked it ).

You can rebuild the motor and make it run stronger, for about 400 bucks. But to tell you the truth, you are just to worried about it...

Also, your rings could be the problem, and it still might not burn oil... Remember, there are more then one type of rings on each piston... From the bottom up, there is a spacer, then a oil ring, a spacer, then two compression rings... If the compression rings are going bad, but the oil ring isnt, then you might not burn oil but still be lower on compression.

John

Yes the valves clearances have been checked, yes it was warm and the throttle plates were open. The spec is anywhere between 154 to 208 psi. 160 psi seems low to me, the bike has 8500 miles. I don't think its the rings because it doesn't burn oil, which would be a strong indication of bad rings.