Jump to content
Sign in to follow this  

So here's to the intake valves.

Recommended Posts

Pulled my head off not only to discover my exhaust valves were loosing compression, but the notorious cupped intake valve as well.

Here's a pic or two of one exhaust ImageUploadedByThumper Talk1400045973.684121.jpg

What do you guys think.. Bought this bike used, exhaust were always in spec on inspection. And one intake always tight.

ImageUploadedByThumper Talk1400045998.950373.jpg

Share this post


Link to post
Share on other sites

What do you guys think.. 

 

I think you need new valves and a decent camera..... :)

How many miles on it.....??

So are your saying that it has had a recent top end rebuild by the previous owner..?...Maybe Kibblewhite junk valves and springs were installed....

Share this post


Link to post
Share on other sites

I think you need new valves and a decent camera..... :)

How many miles on it.....??

So are your saying that it has had a recent top end rebuild by the previous owner..?...Maybe Kibblewhite junk valves and springs were installed....

Kibblewhite junk valves? Did you have bad luck with them?

Share this post


Link to post
Share on other sites

They have very poor wear rates in a DRZ400.....

Do a search on Kibblewhite valves....

 

Interesting. I sure am happy the OEM valves are stainless on my Beta. What other offerings are there? I rode a 03 CRF450 with the Kibblewhites and it ran great. I wonder if it's just a poor wear rate on the DRZ, or on all bikes.

Share this post


Link to post
Share on other sites

Interesting. I sure am happy the OEM valves are stainless on my Beta. What other offerings are there? I rode a 03 CRF450 with the Kibblewhites and it ran great. I wonder if it's just a poor wear rate on the DRZ, or on all bikes.

KW valves work / last just fine in a CRF

Share this post


Link to post
Share on other sites

haha. when i called around to get prices on getting my head rebuilt, almost everyone wanted to use kibble white valves. they all said they didnt know anything about people having problems with them in their drzs. they didnt offer to find any other valves besides those either. needless to say they didnt get the work..

  • Like 1

Share this post


Link to post
Share on other sites

haha. when i called around to get prices on getting my head rebuilt, almost everyone wanted to use kibble white valves. they all said they didnt know anything about people having problems with them in their drzs. they didnt offer to find any other valves besides those either. needless to say they didnt get the work..

 

What if they guarantee the work/product?  Fast Heads is well respected, right? I believe they use KW valves.  I just don't understand what is so special about the DRZ and how it is harder on valves... valves that will work on the CRF450, but not DRZ???  Is the valve seat width really narrow on the DRZ and/or cam profile that causes the valves to impact the seats at high velocities.

Share this post


Link to post
Share on other sites

What if they guarantee the work/product? Fast Heads is well respected, right? I believe they use KW valves. I just don't understand what is so special about the DRZ and how it is harder on valves... valves that will work on the CRF450, but not DRZ??? Is the valve seat width really narrow on the DRZ and/or cam profile that causes the valves to impact the seats at high velocities.

I thought the seat was harder or something. I'm sure they'd find some way to get around the warranty thing by saying I did something wrong with install or say I didn't check the clearances soon enough. I'd rather just trust the other guys that have experience with it. I'm definitely not an expert..

Share this post


Link to post
Share on other sites

I thought the seat was harder or something. I'm sure they'd find some way to get around the warranty thing by saying I did something wrong with install or say I didn't check the clearances soon enough. I'd rather just trust the other guys that have experience with it. I'm definitely not an expert..

I hear ya

Share this post


Link to post
Share on other sites

I think you need new valves and a decent camera..... :)

How many miles on it.....??

So are your saying that it has had a recent top end rebuild by the previous owner..?...Maybe Kibblewhite junk valves and springs were installed....

your right the iphone is junk lol but that's a whole different discussion. I think the previous owner did a "quick" rebuild. probably replaced two valves and that's it.. just lapped em in and called it good. no new springs or seals or guides. luckily im not a dummy, and know how to properly build a top end, only problem is im a veteran two stroker. needless to say the thumpers got me stumped, as far as quality rebuild items go. not sure on mileage, since ive owned it, the vapor dash has gone backwards on mileage.... stumped. I think im on the right track now ladies and gentlemen, thanks to all your input. ill keep ya updated on progress. but you will have to deal with Iphone pictures lol

Edited by rangermilitia

Share this post


Link to post
Share on other sites

My KW valves lasted 3000 KLM

Not a typo

you lucky batcher. it seems you got the holy grail good batch of kibblewhites. they might send you a plaque if you tell them how long they lasted! :jawdrop:

Share this post


Link to post
Share on other sites

 I think the previous owner did a "quick" rebuild. probably replaced two valves and that's it.. just lapped em in and called it good. 

 

Well there is an issue ....You DON'T lap the valves , they must be cut.....

  • Like 1

Share this post


Link to post
Share on other sites

Well there is an issue ....You DON'T lap the valves , they must be cut.....

i was just speculating what the previous owner did.
  • Like 1

Share this post


Link to post
Share on other sites

What if they guarantee the work/product?  Fast Heads is well respected, right? I believe they use KW valves.  I just don't understand what is so special about the DRZ and how it is harder on valves... valves that will work on the CRF450, but not DRZ???  Is the valve seat width really narrow on the DRZ and/or cam profile that causes the valves to impact the seats at high velocities.

When it's time , fit some KW valves to your DRZ ... let us know how it goes

  • Like 1

Share this post


Link to post
Share on other sites

you lucky batcher. it seems you got the holy grail good batch of kibblewhites. they might send you a plaque if you tell them how long they lasted! :jawdrop:

The Head Specialist was shocked at the condition of the KW valves in such a short time .

The seats were cut before installation of the KW Valves .

Share this post


Link to post
Share on other sites

When you say cupped, do you mean the valve it's tuliped or was the margin beaten off the face . In a proper valve job seats can either be ground with multiple angle stones or cut with a three angle cutter, I personally use stones at my shop as I feel that I can make the seat custom to the valve. Not all valves are machined exactly the same so your theoretical margin will differ between two valves outta the same box. Lapping is some old technology but a good engine builder will lap every single valve he puts in, not to grind a seat but to scratch an impression in both the seat and the valve so he knows exactly what point that valve will be operating at, with stones I then can shift the seat around to do what I want, lower on the margin for extended life and wear or higher razor thin seats to create the largest amount flow possible but sacrificing lifespan (race seat).

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×