Topic: is there a way to remove valve springs while the head is on the motor, cb750k

[bucky katt]

i am wondering if there is a tool available to allow me to remove the valve springs from a motor with the head still on and the motor in the frame still (i have an Ilbikes frame kit) i remeber having one that i could do valve springs on a small block ford by bolting the tool onto a rocker stud.

[Whaleman]

The old trick (I have never done it) is to thread 1/4" rope into the spark plug hole until the cylinder is full and the tighten the piston up and the rope holds the valve closed. Dan

[MCRider]

i am wondering if there is a tool available to allow me to remove the valve springs from a motor with the head still on and the motor in the frame still (i have an Ilbikes frame kit) i remeber having one that i could do valve springs on a small block ford by bolting the tool onto a rocker stud.

Yes there is an extrnal valve spring compressor like the last one in this list.

http://www.autozone.com/autozone/catalog/accessories/accessoriesShelf.jsp?brandNValue=&categoryDisplayName=Engine+and+External+Engine&fromType=&fromString=&sortType=&appQuestionId=&parentId=6-10&filterByKeyWord=&currentPage=2&navValue=200480&categoryNValue=&fromWhere=&itemId=480-10&lastPageNo=2&displayName=Valve+Spring+Compressor+and+Measure&ansQListString=&nysQFromType=

I have done this as I had an APE frame tube kit. I removed the HD springs and replaced them with standard as I wanted to tour without the thought of the heavy springs.  YOu set each clinder at TDC and the valve can only drop a tad, till it hits the piston and stop. One at a time it was a breeze. Replaced the seals too.

[bucky katt]

this is the one youre talking about correct?  http://www.autozone.com/autozone/catalog/accessories/accProductDetails.jsp?displayName=ValveSpringCompressorandMeasure&itemId=480-10&navValue=200480&parentId=6-10&productId=414940&fromString=&itemIdentifier=414940_0_0_&filterByKeyWord=&categoryNValue=&store=250&skuDisplayName=Universaloverheadvalvespringcompressor&categoryDisplayName=EngineandExternalEngine&_requestid=1072739

[MCRider]

this is the one youre talking about correct?  http://www.autozone.com/autozone/catalog/accessories/accProductDetails.jsp?displayName=ValveSpringCompressorandMeasure&itemId=480-10&navValue=200480&parentId=6-10&productId=414940&fromString=&itemIdentifier=414940_0_0_&filterByKeyWord=&categoryNValue=&store=250&skuDisplayName=Universaloverheadvalvespringcompressor&categoryDisplayName=EngineandExternalEngine&_requestid=1072739

Yup can't swear to the details, but from the picture that is exactly the one I used.

[madmtnmotors]

I can post a pic this evening, it was a lot simpler than the one in the picture. Used the hose and fitting from my compression tester to feed compressed air from my air compressor into the cylinder to hold the valve closed while I removed the spring and replaced the valve seals on each cylinder.


I actually made my own similar to this one:

[bucky katt]

i kind of remeber an old shadetree mechanics trick of feeding a long, thin nylon rode through the spark plug hole before the piston hits tdc until you cant fit more rope inside the cylinder then turning the motor the rest of the way to tdc, mechanically holding the valves shut. possible with these motors? my compressor appears to be on it's last legs and i dont want to rely on it then have it quit halfway through a job like this.

[754]

You want a thin rope like 1/4in or less, it will fit the space and cushion the valve.

 I dont think I would do it against the piston, as only a small portion , on edge touches..

 You may not want to buy a tool, it should be fairly easy to make.

 You def, want to stuff rags in your camchain cavity, oil drains, and use a screwdriver magnet to catch the keepers....

[MCRider]

snip

 I dont think I would do it against the piston, as only a small portion , on edge touches..

 snip

I did mine relying only on the piston as a valve stop. Worked perfectly, the valve only drops a slight amount, and i wasn't introducing foreign material, although rope would be fairly benign I suppose. I did have a Powroll 888cc kit in it so the pistons had a bit of dome to them.

after setting a cyl at TDC, I removed one spring, then holding the valve stem just lowered it till it stopped and it wasn't very far. But with a flat top piston it could be further.