no compression,but good piston and rings?

[farmer250r]

i have a 06er,it has a good piston and rings are good,but i did a compression check and got nothing,could my valve udjestment be so far out of spec that it would cause it to have no compression,my timing is dead on,could it be a bent valve? im kinda stumped

[fastredrider44]

Tight valves more than likely.

[farmer250r]

would that be the cause of no compession?

[eastside 400]

yes, its most likely your valves. the intakes wear pretty fast, they just arent sealing anymore, time for new valves and a valve job

[farmer250r]

okay so its not just the valves not being udjustred with the right shims,well looks like im gonna send my head to a local shop? or just pick up a used 06+ head with good valves,there about the same price when u are gonna switch to stainless steel,220 for springs,and all that stuff,30 bucks a valve,and what it would cost for install and for them to re-seat them.

[rageatvlawson8]

also you cant do a compression test on a 4stroke cuz the have a decompression lever on them. You could have perfect motor and it will show very low compression. My bet is valves are worn out if your having trouble starting it but using a leak-down tester is the best way to tell

[farmer250r]

well the comperssion tester worked on my cannondale,but that doesnt have a decompeser,the honda does,how do you do a leak down test?

[rageatvlawson8]

need a leak-down tester...special gauge. Just check your valve clearances and see if they are off

[eastside 400]

actually, you can do a compression test, just back off the nut for the adjustment on the decomp so it does not open. For a leak down test you dont really need anything special, just take your compression tester hose and it usually has an air quick connect fitting on it, hook that up to your air line and regulate it at the compressor to about 50PSI or so, put the engine at TDC and listen to any noise comming out the intake or exhaust, that will show bad valves, out the oil breather or oil fill and bad piston/rings/cylinder

[Rich250RRacer]

Originally posted by rageatvlawson8
also you cant do a compression test on a 4stroke cuz the have a decompression lever on them. You could have perfect motor and it will show very low compression. My bet is valves are worn out if your having trouble starting it but using a leak-down tester is the best way to tell

What?...........................Maybe you should look at a Honda service manual, it lists specs to do a compression test, and yes, that's with the decompressor still operational. Not to rag you buddy, but if you don't know the information, you shouldn't be giving the advice. It may do more harm than good.

Here are the correct specs according the Honda service manual.

04-05 108 lbs.
06-up 450ER 50-56 lbs.
06-up 450R 139-145 lbs.

[rageatvlawson8]

ok yes you can do one kinda...BUT if you dont have the manual then that number will seem very low. Also your not really checking compression doing that, your checking more where the decomp opens at as you could adjust the decomp tighter or looser depending on how your motor configure wants it and that number will change. BUT for checking the motor internals its still not a good test. I just didnt go into more detail as it seemed that the reason he said his motor was hurt was a low number on his compression gauge.....

[eastside 400]

i agree, you cannot check the engines compression correctly with the decomp still hooked up. That just tells you how much compression you have before it is released, you might be able to get the spec but something might still be wrong since 140psi is less then what actual compression should be

[Rich250RRacer]

If you know the decompressor is adjusted properly, then these specs are good. They take into account the decompressor. That's why they list specs for it. If you fall below they're recommended range, then you know something needs attention. Reading, it's a wonderful thing.

[Rich250RRacer]

Originally posted by eastside 400
i agree, you cannot check the engines compression correctly with the decomp still hooked up. That just tells you how much compression you have before it is released, you might be able to get the spec but something might still be wrong since 140psi is less then what actual compression should be

That statement just makes no sense.

[DnB_racing]

Originally posted by Rich250RRacer
If you know the decompressor is adjusted properly, then these specs are good. They take into account the decompressor. That's why they list specs for it. If you fall below they're recommended range, then you know something needs attention. Reading, it's a wonderful thing. I know what your trying to say but come on... you know this is not the best situation to check actual compression at the valves,,especially on an er like this one is!!!

stop trying to make an argument out of this,,, a leak down test is the much better method for a motor with a decompressor to check for leaks
a compression test might show that you have a problem, were a leakdown test will show you were your problem is!!

[farmer250r]

ok,well im gonna udjest the valves to spec,then see if that makes a diffrents,if not that,ill redo the valves,that should be done anyway,but cash is key,and dont have alot of cash flow right now,if anyone has a 06+ head with good valves for sale pm me.cuz valves are gonna be like 400 at the local shop,kw valves and stainless steal,with springs,and to re-seat them.

[DnB_racing]

if you keep your air cleaner and gas REAL clean you should get many hours out of the valves, not cleaning and oiling your air filter every ride is the worst thing to do to your valve train!!!!

[farmer250r]

i always clean my fliter.pj1 filter cleaner and oil,but i think ill be getting the filter skins too,and the air box fliter skin too,since im not runing the airbox lid.

[eastside 400]

if your valves are still in spec and didnt tighten up then the valves and seats should usually be in good condition, when they start to wear they will get tighter. I hope that statement is ok to say by others since he knows everything there is to know since he can read a honda manual

[farmer250r]

my valve are too tight,so im gonna udjust them,then gonna do valves if that doesnt work

[Rich250RRacer]

Originally posted by DnB_racing
I know what your trying to say but come on... you know this is not the best situation to check actual compression at the valves,,especially on an er like this one is!!!

stop trying to make an argument out of this,,, a leak down test is the much better method for a motor with a decompressor to check for leaks
a compression test might show that you have a problem, were a leakdown test will show you were your problem is!!

I'm trying to help the guy out while one guy is trying to tell him he needs a $250 leak down tester to figure this out. And I don't know what the hell the other guy is trying to say. You call it an arguement, then fine, that's what it is, but I'm going to go over this one more time so maybe you can wrap your mind round it too.

The owner of this quad seems somewhat mechanically inclined so I'm sure he can make sure his decompressor is set correctly. Now just suppose he screws a compression tester in there and going by the specs that some highly paid engineers are giving us, the compression is lower than it should be. What does that mean? Wait for it.........................................somethi ng is WRONG. Decompressor or not, those specs are given to you for a reason. Are you comprehending this so far? Some part is not performing it's intended job to the fullest extent. So now it's time to use the brain god gave you....... boy I hope it works. Now follow along carefully, because this gets pretty technical. Is the cooling system getting pressurized? No, well then that leaves valves and rings. Now all of you may be a little wet behind the ears, so you may have never heard of this next step. Maybe he can pour about a tablespoon of oil down the spark plug hole and immediately retest the compression. What do you think that will show? Hmmm, maybe that coat of oil that's now in there will temporarily create a better seal around the rings. So class, if the compression increases after the oil is added, what does this mean? Figure it out yet? That means the rings are bad. If the compression didn't increase, what does that mean? Did I hear bad valves? No, you couldn't figure that one out either? So while I could have pulled my leakdown tester out, I used my $30 compression tester, a little bit of oil, and a fully functioning brain to figure out the problem. That's the end of my arguement, if you have anything to say otherwise, I'll be happy to reopen it.

[DnB_racing]

Originally posted by Rich250RRacer
I'm trying to help the guy out while one guy is trying to tell him he needs a $250 leak down tester to figure this out. And I don't know what the hell the other guy is trying to say. You call it an arguement, then fine, that's what it is, but I'm going to go over this one more time so maybe you can wrap your mind round it too.

The owner of this quad seems somewhat mechanically inclined so I'm sure he can make sure his decompressor is set correctly. Now just suppose he screws a compression tester in there and going by the specs that some highly paid engineers are giving us, the compression is lower than it should be. What does that mean? Wait for it.........................................somethi ng is WRONG. Decompressor or not, those specs are given to you for a reason. Are you comprehending this so far? Some part is not performing it's intended job to the fullest extent. So now it's time to use the brain god gave you....... boy I hope it works. Now follow along carefully, because this gets pretty technical. Is the cooling system getting pressurized? No, well then that leaves valves and rings. Now all of you may be a little wet behind the ears, so you may have never heard of this next step. Maybe he can pour about a tablespoon of oil down the spark plug hole and immediately retest the compression. What do you think that will show? Hmmm, maybe that coat of oil that's now in there will temporarily create a better seal around the rings. So class, if the compression increases after the oil is added, what does this mean? Figure it out yet? That means the rings are bad. If the compression didn't increase, what does that mean? Did I hear bad valves? No, you couldn't figure that one out either? So while I could have pulled my leakdown tester out, I used my $30 compression tester, a little bit of oil, and a fully functioning brain to figure out the problem. That's the end of my arguement, if you have anything to say otherwise, I'll be happy to reopen it. what are you having a bad day and just want to insult anyone???you dont have to be sarcastic thats why people are afraid to post lately!!

you have your ways and I have mine!you like your way and i like mine

I use my tester that I made for free at work, and if there is a problem with a spray bottle i can check for leaking head gasket or or with a good ear I can hear the leak ,,just my way!! but if you want to do yours then fine and which ever way the poster wants to do his

but you dont have to insult anyone that does things differently from you!!

the first thing I do when a quad comes in with unknown problem is a leak down test! no worries of causing any damage or even have to worry about battery, it only take minutes and eliminates many possible problem areas safely!!

but im not saying that yours is wrong !!just not my way!!

we have someone from rage trying to help and this is how we chase away someone that has a true value to this site!! so please rember that anyone can have valuble info!!

[Baileygunns]

For a second there I thought I was on the .org...

lol

[MX450]

no if we were on the org everyone would have just told the guy to buy a venom piston and send the head to racers edge :blah:

[Ruf Racing]

Originally posted by MX450
no if we were on the org everyone would have just told the guy to buy a venom piston and send the head to racers edge :blah:

Don't forget the Dasa exhaust too! lol! :D

[Baileygunns]

And put an HRC jet kit in it... That should fix it, lol...