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Can valve seals be changed without removing the heads?


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I just want to change the valve seals on my XRL and I am not really interested in removing the heads if at all possible. I heard that using compressed air you can keep the valves from opening. Anyone know how to do this?

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Put the piston at BDC and check that the valves are closed (it will be obvious later if they aren't). Thread an air hose fitting into a broken-out spark plug and thread that into the sparkplug hole. Connect that to an air compressor and crank it up to about 120 psi.

If you whack the valve trying to break the "seal" of the keeper, all bets are off as that can open the valve and let the pressure out.

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I just want to change the valve seals on my XRL and I am not really interested in removing the heads if at all possible. I heard that using compressed air you can keep the valves from opening. Anyone know how to do this?

Where are you,,i`m in Moncton...i have probably all the tools needed to do this on the bike for you since i`m a mechanic...i`m still laid off for a bit...

What is needed is an air compressor,and part of my compression guage set from Mac Tools includes an adapter to air up the cylinder so the valves cannot drop into the cylinder when the springs are removed..

I also have a valve spring compressor that is used to do this exact job on a car without pulling the head...if it won`t fit we can make a tool i`m sure pretty easy...

Let me know if you`re interested..i only charge a small amount in BEER...👍

PM me if interested.........i`m doing absolutely bugger all this weekend...

B

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Put the piston at BDC and check that the valves are closed (it will be obvious later if they aren't). Thread an air hose fitting into a broken-out spark plug and thread that into the sparkplug hole. Connect that to an air compressor and crank it up to about 120 psi.

If you whack the valve trying to break the "seal" of the keeper, all bets are off as that can open the valve and let the pressure out.

Actually if you air up the cylinder and compress the spring a little and wack the top holder a little,it`ll let out a pop of air,,if even that,,as the air pressure will snap the valve shut in milliseconds....i do this all the time on cars/bikes/snowblowers.....you name it............only thing to be aware of is some idiot unplugging your air line...label the hose,or wrap the quick connectors with black tape so you have time to slap the crap out of him before he unplugs it:thumbsup:👍🤣

B

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Thanks for the tips brianhare. I live in Tracadie up north so its quite far. I do have a big compressor and I have access to valve spring compression tools. I was just wanting to make sure that it was able to be done. Thanks for the procedure. Too bad I wasn't closer or I would have certainly bought a case of beers to share with you. 👍

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Thanks for the tips brianhare. I live in Tracadie up north so its quite far. I do have a big compressor and I have access to valve spring compression tools. I was just wanting to make sure that it was able to be done. Thanks for the procedure. Too bad I wasn't closer or I would have certainly bought a case of beers to share with you. 🤣

Yeah,,,,,,that sucks,,,my bud buys a freekin old crotch rocket,i need a niehbour with a pig.👍...i like to drive on road just long enough to get off road...too bad you weren`t closer...i like a reason to drink beer:thumbsup:

P.S. i seem to remember now asking you where you lived:banghead:..but i can`t remember where all the people i talk to live,you meet a ton of nice people on these forums..

B

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Dot-Com.......one other thing to do which can be a life saver on this job,,pull the cover that covers the bolt for turning the crankshaft and put a 1/2 inch power bar with a 17mm socket on the crank...then wire the long handle to the frame or anyplace to prevent the power bar from moving after you have made sure the piston is at TDC.......the reason for doing this is if you loose air pressure the valves cannot drop into the cylinder...a small tipped magnet will pickup the valve if it drops down the guide any..this may sound like overkill,,,but it saved me once..once you plug in the air the crank will try to turn........and if you don`t wire the handle secure it`ll go flyin:lol:

B

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I have a friend in Moncton that looking to buy a BRP. He went to toy's for big boys and they have a 2008 leftover that they want $6500 on the road. He was also tempted to get a KLR for $1000 less but I think I persuaded him otherwise. Any good second hand BRPs with low mileage that you know of?

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Dot-Com.......one other thing to do which can be a life saver on this job,,pull the cover that covers the bolt for turning the crankshaft and put a 1/2 inch power bar with a 17mm socket on the crank...then wire the long handle to the frame or anyplace to prevent the power bar from moving after you have made sure the piston is at TDC.......the reason for doing this is if you loose air pressure the valves cannot drop into the cylinder...a small tipped magnet will pickup the valve if it drops down the guide any..this may sound like overkill,,,but it saved me once..once you plug in the air the crank will try to turn........and if you don`t wire the handle secure it`ll go flyin:lol:

B

I was thinking of keeping it not at TDC but BDC only because if I need to tap the valves to unsieze the spring locks I was thinking there would be no chance that the valves could hit the top of the piston and potentially bend my valves.

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I was thinking of keeping it not at TDC but BDC only because if I need to tap the valves to unsieze the spring locks I was thinking there would be no chance that the valves could hit the top of the piston and potentially bend my valves.

Don`t believe that would happen,,just a light tap is all that`s need,,they won`t move much,,if any......but as long as the air pressure stays on it doesn`t really matter if its at BDC or TDC,,,

There was a nice low mile XRL on KIJIJI up until last week for 5495 or so...i think it`s gone now though...

P.S. here`s somethin you can do while the cylinder is aired up and the cam cover is off.........take a BBQ lighter or BIC lighter,,and hold it close to the exhaust exit and also the intake port(since the carb will be off).......see how much the flame flickers.......if it moves alot,you might wanna consider lapping/reseating the valves..my exhaust valves were leaking somewhat bad.....

Just something to consider,since you`re thinking of a cam,pulling the head is easy.....and costs about 60-80 bucks i think for the valves and seats to be recut.........

B

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Hi All

What sort of valve spring compressor are you using? The one I have fits onto the bottom of the valve, unless I'm not getting the full pcture.

Be nice to do this job with out all the hassle of taking the head off.

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Don`t believe that would happen,,just a light tap is all that`s need,,they won`t move much,,if any......but as long as the air pressure stays on it doesn`t really matter if its at BDC or TDC,,,

There was a nice low mile XRL on KIJIJI up until last week for 5495 or so...i think it`s gone now though...

P.S. here`s somethin you can do while the cylinder is aired up and the cam cover is off.........take a BBQ lighter or BIC lighter,,and hold it close to the exhaust exit and also the intake port(since the carb will be off).......see how much the flame flickers.......if it moves alot,you might wanna consider lapping/reseating the valves..my exhaust valves were leaking somewhat bad.....

Just something to consider,since you`re thinking of a cam,pulling the head is easy.....and costs about 60-80 bucks i think for the valves and seats to be recut.........

B

Well I really don't think I need a valve job but I will do a test. I don't plan on tearing my engine apart until next winter. It works really good. Lots of compression just a big puff of blue smoke when starting cold. Does not consume any oil so I'm suspecting valve seals. If I can't do this without removing the heads I will probably live with it till next winter. Also I am not sure if its my seals at all. I smokes quite a bit almost scary sometimes. The only thing else that I can think that might cause this is could be the smog system I took off. The pipe running from the crankcase to the airbox is kinda stretched and the pipe has a sharp bend near the crankcase. It might be acting sorta like a check valve trapping in oil and when it starts it sucks it through the airbox and into the carb. The blue smoke is not always present when I start it. Sometimes it not present , sometimes it smokes a little and sometimes it just spurts out a big blue trail. The funny thing is the oil level might drop 1/2 quart in 2000miles which is very good considering the oil has to come from somewhere. After is heats up it works great and no smoke at all. Sparkplug looks great too.

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Well I really don't think I need a valve job but I will do a test. I don't plan on tearing my engine apart until next winter. It works really good. Lots of compression just a big puff of blue smoke when starting cold. Does not consume any oil so I'm suspecting valve seals. If I can't do this without removing the heads I will probably live with it till next winter. Also I am not sure if its my seals at all. I smokes quite a bit almost scary sometimes. The only thing else that I can think that might cause this is could be the smog system I took off. The pipe running from the crankcase to the airbox is kinda stretched and the pipe has a sharp bend near the crankcase. It might be acting sorta like a check valve trapping in oil and when it starts it sucks it through the airbox and into the carb. The blue smoke is not always present when I start it. Sometimes it not present , sometimes it smokes a little and sometimes it just spurts out a big blue trail. The funny thing is the oil level might drop 1/2 quart in 2000miles which is very good considering the oil has to come from somewhere. After is heats up it works great and no smoke at all. Sparkplug looks great too.

Man.......no offence Dot-Com......but why are people removing the oil separator....geeeeeeeeeezzzzzzzzz...it`s not smog equipment as much as it`s an oil separator....there is one person here that ruined an engine from doing this......IMHO i`d never remove that separator..the only reason i removed the octypus crap was to get rid of the popin on decel....

I don`t know maybe i`m wrong,but i never found in all the searches/threads/people i`ve talked too,any good coming from removing that oil separator...the only thing it would help is getting at the idle screw easier...

Everytime the piston goes down air/oil vapour goes out,,when the piston goes up air goes in.......the crankcase has to breath properly...

B

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Be nice to do this job with out all the hassle of taking the head off.

Personally, I think it's just as much trouble to do it with the head still installed. It also carries the risk of dinging the cylinder if a valve gets dropped in and then the head has to come off anyway.

Also I am not sure if its my seals at all.

You could pull the header off after the bike sits overnight and look for oil on the valves. Also check the airbox for engine oil coming from the breather. If it smokes inconsistently, then it probably isn't the valve seals.

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Man.......no offence Dot-Com......but why are people removing the oil separator....geeeeeeeeeezzzzzzzzz...it`s not smog equipment as much as it`s an oil separator....there is one person here that ruined an engine from doing this......IMHO i`d never remove that separator..the only reason i removed the octypus crap was to get rid of the popin on decel....

I don`t know maybe i`m wrong,but i never found in all the searches/threads/people i`ve talked too,any good coming from removing that oil separator...the only thing it would help is getting at the idle screw easier...

Everytime the piston goes down air/oil vapour goes out,,when the piston goes up air goes in.......the crankcase has to breath properly...

B

Well I took it off because when I got the bike the guy had put a jet kit and it was not tuned right at all. Then after I tried an XRR carb and was frigging with that for awhile and no I put a FCR-MX carb and your right it was mainly because I wanted easier access to the leak jet and pilot screw. From what I read it was something a lot of people were doing with no ill effects. Beside the older bikes before this smog stuff came out had the crankcase breather routed to the airbox? How did this person here ruin his engine?

You could pull the header off after the bike sits overnight and look for oil on the valves. Also check the airbox for engine oil coming from the breather. If it smokes inconsistently, then it probably isn't the valve seals.

When I install my wide band O2 probe I will have to remove the header to weld the bung, I will check then. I never had this smoking problem until I removed the smog equipment. I'm going to try a longer hose so that I don't get a 90 degree kink right where the hose connects to the crankcase. Right now instead of a nice 90 degree bend the hose kinks sharply and I'm sure it acts somewhat like a check valve.

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I was thinking of keeping it not at TDC but BDC only because if I need to tap the valves to unsieze the spring locks I was thinking there would be no chance that the valves could hit the top of the piston and potentially bend my valves.

BDC so that the air won't cause the crank to rotate (which can happen at TDC). TDC is okay if you lock the crank in place (with a breaker bar or something; the clutch isn't a good idea in case it's grabbed...)

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I'd try disconnecting the breather from the air box all together if you think that might be the cause of the smoke. Plug the hole to the airbox and put a cheap filter on the breather to make sure you don't suck any crap in while testing it. Then take it for a thrash and see what happens. No point trying to fix it if it ain't broke. If that cures the problem refit the seperator, improve your existing pipework or run the breather with a filter as some do.

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I'd try disconnecting the breather from the air box all together if you think that might be the cause of the smoke. Plug the hole to the airbox and put a cheap filter on the breather to make sure you don't suck any crap in while testing it. Then take it for a thrash and see what happens. No point trying to fix it if it ain't broke. If that cures the problem refit the seperator, improve your existing pipework or run the breather with a filter as some do.

Yep I plan on doing that but I dont have to thrash it because this intermittent smoking problem only happens the first time I start the engine. I'll disconnect the tube every time I start the engine for awhile to see if the smoking problem disappears.

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