Valves are 900 and 1000 the same??

Ok long story short timing messed up and the intake valves got bent in my 1000 so I replaced them with valves from a 900 head the valves were the same diameter but I need to know would they be the same length.I have everything back together and cylinders 1,2,4 have no compresion and 3 has 140 pounds. I have reset the cams and the timing manytimes and still no compresion I am very "F$#%^&G"frustrated. PLEASE HELP!!!!!!!! :S :blink: :dry: :ohmy: :ohmy: :dry:

dont know if they are the same size or not,,,but did you grind the valves and seats, if not they will not seat properly,, also were you able to set the valve clearance,
I suspect the valves are not seating, you can use the compression guage to fill the cyl with air you will see or hear where the air is going real quick

Yes I laped them in and did the shims for clearences. My compresion tester is one piece so is there any way else to put air in??

Did you make sure the split retainers are the same for each valve. Some valves have a round profile groove in the valve and some have a square profile groove. Not sure if that's your problem but it's easliy overlooked.

Later, Doug

The basic dimensions are the same - 30mm exhaust, 36mm intake on the size. The stem is the same length. All 900 valves have a square cut groove in the stem versus an evenly radiused groove in the 1000 valves. They do interchange as long as you use the correct keepers.

I used the keepers from the 1000 not the 900 (900 valves with 1000 keepers)would this be keeping the the valves open a little and making so I have no compresion??

I would not run the engine that way. I would hate to see you do more damage.

The round (kz1000) keepers will not sit perfectly in the groove - this will allow the stem to move up and down a little inside the keeper - eventually resulting in a big problem.

Jeff is correct. Unless someone had put 1000 valves in the 900 head, which is quite common, you run a high risk of dropping a valve into the engine. You need to get the head off ASAP and check it out.

After you determine it is OK, take the head to a shop that has a vacuum tester and have it checked to see if it is sealing.
Jay

learn something new every day,, didnt think about keepers being different

I'll check everthing out and get back to you all. Right now I'm going to figure out somthing to air up the cylinder and see where its leaking.Thanks;)

fill ports full of solvent and blow compressed air around seats of valves to see if they are seating .im not a big fan of valve lapping id rather have them ground to know ive got a good seal if im gonna go to all the trouble.

FOUND THE PROBLEM!!!!!!! Warning do not use the keepers from a 1000 on a 900 valve they do not close all the way. Who new not me I gess. Thanks for all the help. I'll let you all know tommorow when I get it running.
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