mike perry

Sponsoring Member
May 20, 2002
44
0
With the increased amount of 4 stroke DIYers, we've had a huge amount of phone calls from folks needing help installing the KPMI spring kit that they buy to go along with the Black Diamond valves.

The conversations often start out with a statement that goes something like this:

"The valve tip is too long, there is no room for the adjustment shim".

What has happened to this one person race team is that he or she has mixed up the components. If you try to put the exhust retainer on the intake valve the retainer won't pull up far enough to locate in the correct position.

So here are a few tips to make you feel like Team Honda should be hiring you to do the top end work on their bikes:

1- Don't mix the components in the kit up when you open the packages. The valve stems have different diameters, so the keepers and retainers from the intake side won't fit correctly on the exhaust side.

2- For you two stroke converts- the intake valve has a larger head than the exhaust. And No, that doesn't make it smarter. Sheesh!

3- Remove all of the stock pieces. Retainers, keepers,
and lower collars (AKA bases) You won't be using them over again, and they will interfere with the installation of the new components.

3- Take a look at how the stock parts fit when you are taking the head apart. Note how the keepers fit in the groove and around the valve stem, and how the retainers fit when pulled up tight on the valve.

4- The springs in the kit are different too. The intake tappets won't fit over our exhaust springs, so if you somehow manage to get the wrong springs on the intake side, you would have to force the tappets over them. There should be no contact between the spring and the tappet.

5- The copper colored valve spring shim goes underneath the exhaust spring lower collar. That would make it the lowest piece of the assembly.

6- The Installed height that we mention in the kit (and that most spring manufacturers refer to) is the distance between the surfaces of the retainer and the lower collar that the outer spring contacts when the pieces are assembled.

7- You will probably have to use different adjustment shims than the ones that are in the head now. Our valves are a few thosandths shorter than stock to leave room for a valve job, without running out of shim range.

8- There is about .400" (four hundred thousanths) travel from the bottom of the retainer to the top of the valve stem seal. If you are going to run a cam with lift that approachs .400", you need to make more room between the guide and the retainer. (Personally I don't like to get closer than .040".) We sell a guide that is shorter on the top to give you more room.

9- If you determine you need to change guides, they should be installed and honed to clearance by someone who has the right equipment to do the job. Most likely you wont have a perfect guide to seat relationship after replacing the guide, and you will need to touch up the valve job too, after changing the guides.

10- If it doesn't seem right it probably isn't. This is a saying we have on our Drag Race team. Too many times we've said- "It's probably supposed to be that way" only to find out that our initial skepticism was warranted. Don't let being in a rush, or being determined to get the bike together for a ride "in the morning" be the determining factor in your decision making process. If after going through the process something doesn't seem right, make the phone call. Don't make a $5000.00 mistake that could have been prevented by putting the ride off for a few days.

When you get the Honda job- don't forget the little folks who helped you on your way up.

Diagnostics-
I can't tell you over the phone if you need to do a valve job, or change the guides or seals. If you have any question at all about the condition of the rest of the parts in the head I suggest you take or send the head to someone with a good reputation for doing quality motorcycle head work. As noted in other parts of the discussion forum it is now the insane time of the year. You may have to wait a couple of weeks to have anyone look at your job.

Finally-
For all of those folks who have been patiently waiting (and for those who have been impatiently waiting too) the Black Diamond valves should be off the production floor and into final Q/A at the end of the month. Back orders should be filled to all the distributors and dealers by the first full week in April.
I know some of you have missed a couple of weeks, but this latest delivery should give most folks a full 6 months to ride.

Hope this info is of some help to someone out there...

Mike
 

Rich Rohrich

Moderator / BioHazard
LIFETIME SPONSOR
Jul 27, 1999
22,838
16,902
Chicago
Great stuff. Thanks Mike.
 

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