| Author | Message | ||
     Ryker77 |
I was talking with my father-in-law about needing to replace my valve seal. He tells me to use and air to spark plug adaptor and fill that cyclinder full of air. This would hold the valve in place so that the valve spring could be released -- all without pulling the head off of the bike. that would be a sweet deal, for me 2002 Xl with Xb heads | ||
| Crashm1 |
Well it works on cars. I'm doing a Toyota on Monday. Having enough room to use a valve spring compressor without taking the engine out could be tricky. Also the compressors I'm familiar with use a bolt hole or rocker arm stud as the pivot point to get the leverage needed to compress the spring. | ||
| Whodom |
Another good technique is to get a length of small diameter (and clean) rope. Remove the plug, set the piston a little below TDC, and push rope in through the spark plug hole until it's full. Then turn the crank a little to compress the rope which will hold the valves firmly in place. It's a good method if you don't have an air compressor and/or plug adapter handy. I successfully used this technique on a Mitsu 4-cylinder in a Dodge Ram 50 truck I used to have. | ||
| Ryker77 |
how much air psi should be used? | ||
| Rocketman |
Depends on the spring pressure but I'm sure Blake will be able to post the formula chapter and verse  Rocket | ||
| Panic |
About 1/3 of the seated spring load should do it. | ||
| Aaomy |
normally to do this you need a special valve spring compressor that locks over the spring and allows you to compress the spring rather that the traditional sense of "c clamp" style. where the one end is on the valve and the other is on the top valve spring retainer. all of these small type spring compressors i have seen, have been designed for the traditional valve springs not the xb "bee hive" style springs. i suppose a cool little tool could be created that would allow you to use the current rocker shaft as a pivot point and a forked end to " pry down" the upper retainer so that the retainer clip could be removed. just an idea though.. | ||
| Bandm |
Remove the rocker arms Air up cylinder Place 5/8 deep socket on retainer and tap with hammer to unseat locks Put tool under rocker shaft and depress spring Remove locks with a magnet Release tool Remove spring Remove seal  Tapping the retainer to unseat the locks is the secret. Use as much air pressure as you have. If the locks don't unseat, (valves open when tapping) pressure is too low. Maintain pressure while locks are removed. Air compressor must have enough capacity to maintain pressure, as air will leak past rings and valves (leak down). Mark | ||
| Ryker77 |
Mark  thanks soo much. just tell me the name or brand of that tool so I can buy it. once again thanks | ||
| Bandm |
OTC 7928 Ford Valve Spring Compressor Other companies make similar tools | ||
| Blake |
I like my Aeron seat just fine thanks. No formulas required.  | ||
| Pammy |
Just take the head off and do it properly. Get some viton seals. Why are you having to replace them? Are they leaking or dis-lodged? | ||
| Phat_j |
you tell em pammy..... in all the time looking for alternatives, you could have done the job a few times over... | ||
| Ryker77 |
Properly---- ? Just becuase one method takes longer doesn't make it a better method. But heck I've never done it either way, so I can't argue.... Plus I had though it was not a good idea to keep removing the front motor mount from the head. ?? Front head fouls plugs. On the decel of the throttle smoke will belt out. I had been told that the pressure in the engine on decel of RPMS would force oil through a bad valve seal. I think the previous owner rode the •••• out of the bike even though is was badly out of tune. So Viton seals is what I'll get. Hurricane seals sure didn't last long. | ||
| Jackbequick |
The M2 service manual says not to remove the motor mount, that the head will slide out to the right side. But it also details the procedure for removing the mount. Calls for a new bolt, cleaning the threads out with a tap, using red LocTite. I'd heat the old bolt up real good before I tried to get it out, it might make the old LocTite let go a little easier. | ||
| Rocketman |
I had been told........................... Ryker, excuse me for saying so but if you don't know exactly why or what you are really looking for then you need to do the work more thoroughly. Remove the top end of your motor and give it the attention to detail it needs in order to make it work properly. If you find that to daunting then you shouldn't be doing the work at all yourself. Pay a technician who knows what and how to do it and keep us in a living. Thanks Rocket | ||
| Newfie_buell |
For the amount of time it takes to pull the head, its worth pulling it and having the head rebuilt properly. | ||
| Bandm |
Pulling the head seems like a lot of work to change a valve seal. Sounds like a leak down test is in order. If rings and valves check out OK, changing valve seals would take minutes more than changing rocker box gaskets. If valves or rings have excessive leakage, the "proper" repair would be to remove both heads and both cylinders. Heads would need cleaning, seats cut, valves ground, guides replaced or reconditioned, seals and springs replaced. With heads removed, base gaskets are no longer clamped, requiring replacement. With the cylinders removed boring and/or honing to fit new pistons and rings would be next. The list keeps growing. The "proper" way will fix the problem even if it is only a bad valve seal, but so will changing only the seal. Correctly diagnosing the problem beats throwing parts and labor at it every time. Mark | ||
| Phat_j |
ryker, if your worried about removing the mount from the head, dont.... remove the one bolt from the mount to the frame, lower the motor a bit, and then remove head and mount at the same time... | ||
| Newfie_buell |
Even if the mount is removed and the motor secured to the frame with a strap. All you have to do is clean the threads in the head and replace ALL bolts with new ones. If I had a bad seal I'd pull the head and just refresh whatever is in there. For the sake of a few dollars the top end is refreshed and should not take any longer than a day to complete the work. | ||
| Mr_grumpy |
There's an old saying, "If a job's worth doing, it's worth doing well" don't muck about. do the leak down test if you have the equipment, to be sure the rings are ok as well; If you just do the valve seal & it's not just that, you'll have to strip it again anyway. Do a proper job first time round & forget about it. Just my €2 worth; |
