Cam/valve lash?

[turbocamino]

    Robert got me a couple Web 540 hard welds for a 1297 engine.  I kept my stock cams and bought a pair of new ones he sells and Web used those. Turns out i didn't build the 1297 but kept the 1250 setup along with a seriously ported head with stock valves. It runs great up in the RPM range but soft down low.  I plan to put the stock cams back in this spring.  So,,my question... what are the chances the valve lash will be the same?...   i will certainly check the lash..just planning ahead as i don't have too many shims.  Thanks

[Pat Conlon]

Base circle the same?

[turbocamino]

Robert did say they are OEM Yamaha..so i assume base circle to be same ,,hopefully.

[RPM - Robert]

Base circle is the same as far as the stock cams. I believe They only weld/grind on the duration and lift, as far as I know, so the base should be the same after they come back. The lash should be the same. I think the only thing Web recommends is a different degree setting for the cams.

Did you degree the cams in? Their recommendation per grind is in each box when they send them out.

[turbocamino]

  Yes..cams degreed...we used the #s you,and Web,had suggested 106int/108exh.  I realize i could play with those settings to move the power range down some. Not sure of the best course of action? Maybe some more jetting is needed as well.  I have the feeling that the lose of port velocity from the major head work , along with the 540s duration,going from 233 stock to 248 , thats a huge jump in the midrange. Open for suggestions.

[RPM - Robert]

I would try some main jet needle adjustments if it is flat
Low and running well on the mid to big end.

Stock needles or aftermarket?

Also, those cams work better with higher compression pistons. We're the 1250 pistons stock?

[turbocamino]

   Yes Xj1250 oem spec comp. is around 10/1 with the head skimmed. The needles are DynoJet..somewhere in the middle. I believe i put the 125mikuni in it you sent me.  It runs properly... just a bit week 2-4000k range...makes up for the lose in a big way 6-10k though...just not where i am most of the time. I have been looking at widebands to try..probably the only way to be certain on jetting?  Also figuring the stock cams would make the midrange tuning easier?

[RPM - Robert]

Also figuring the stock cams would make the midrange tuning easier?

Not necessarily, the head has been worked over so you are going to need to do some dyno or pulls with an afr to get it tuned up, properly. The dynojet needles are more lean the stock needles, if I remember off the top of my head. I'm not at the shop to look but I believe they are thicker which would make it more lean. I would try raising the main jet needles all the way(dropping the clip to the lowest setting). This will richen it up and will be the easiest thing to change first. You don't even need to remove the carbs to make this change.

Are you running the dynojet diaphragm spring as well? This dynojet spring is stiffer than stock spring which will also keep the needle in the emulsion tube longer, thus making it leaner longer.

I know on pats 1380 we ended up with some custom big bore needles that we have. They are tapered a bit more aggressively and they are a bit thinner from mid way up the shaft to the tip. This richness it up all the way throughout quicker than stock or dynojet.

Yes, wideband or someone with a afr sniffer hooked up to their dyno should be able to get you spot on. Either way with the head changes it is going to be best to get afr numbers with or without stock cams.

[fj1289]

As much as I'd like the chance to low-ball you for those cams!     I really think you need to keep them and tweak the tuning just a bit.  They really are pretty mild cams that are great for street use.  Once you get everything dialed in "right" you will discover the differences between a bike running, vs a bike the runs well, and a bike that is spot-on! 

My first time learning that was a little XJ650RJ Seca I put a header and a set of CR smooth bore carbs that were supposed to "run out of the box".  They did, and the result was somewhat less than I expected.  I spent maybe 2 or 3 weeks learning what each circuit in the carbs did and how to tune each.  Each day on my 20 minute or so ride to work (with a variety of riding conditions) I would make a single change (by a single step) and document it.   Then repeat the next day - changing the same thing the same direction - document better or worse?  If it gets better, keep going in that direction, if worse go the other way.   By the end of all that, I had a bike the idles great, smooth take up from idle, smooth and economical in cruise, very responsive in the mid range, and great top end pull.   That's how I learned the difference between a bike that runs, runs well, and runs RIGHT!

I think you will love those cams - especially with the head work - just needs to sharpen the tune a bit!   

[turbocamino]

   Thank you guys for giving some direction!..wasn't really wanting to take it apart again...a buddy has the degree wheel/cam timing job down pretty well but lives out of town and getting him here for an afternoon isnt' so easy.  Also,Robert,  yes, it does have the diaphragm springs from the DJ kit.,,never thought of that or the needles being leaner than the stock design?  Is there a better design overall?  factory pro maybe?  i think i have the stock springs someplace,probably the needles too?      Chris, i wish i had your patience..as i get older time seems to escape me and i make wholesale changes...not too scientific : /   I do look forward to it running "right"   There is a shop about an hour away with a dyno that may be able to rent me some time.  I will spend some time tuning and maybe these cams will stay.

[RPM - Robert]

Try raising the current needles and swapping the springs back to stock. The stock needles are adjustable so not much you can do there without adding a bunch of shims to get the needle up out of the hole to richen it up.

Yes, I do have needles that I use for bigger bore and modified builds that need more fuel. They are what we used on Pats bike as well as simi Ed and numerous other modified setups.

[Bozo]

FYI, my 540 Web cams (I bought through RPM), ported, Std valves, 1219? Wiseco, 4-1, I am currently using FZ1 37mm carbies  with some modifications. Just ran an ML-2 AFR meter (with O2sensor in exhaust), the carbies have just about perfect AFR reading, steady cruising 14.5 approx (100 to 140kph), hard acceleration just over 13.
Currently I have a 132 mains but because at 7,500+ the reading is 15 to 16 I will go to a 135 mains.
I have no problems down low (pulls from 50kph in top) and after 4,000 it hauls all the way up.
I believe the only way to get your bike right is to tune the carbies (assuming the dial-in is correct). Without the meter I found (using my previous std 36mm carbies) I was running lean at the top (before the AFR) and at 4,000 it had a big dip i.e rich mixture down to 9 and yet I thought at the time it ran great.
Good luck, once tuned you'll love those cams.

[turbocamino]

  The FZ carbs interest me.. i just read your experience with your from Dec 21.  Our engines are similar as well. I will give it all some though..thanks for all the input.

[JMR]

 I have had not so good experiences with base circles and WEB cams....about -.010 off the base with that 540 grind in my personal bike and similar experiences with Kawasaki grinds and large Hayabusa grinds. SOB 9.5mm conversion offers a larger variety of shims especially on the far side of thickness.
I set my 540 grind lobe centers at 105/105.....ubiquitous Yoshimura cam #s and the power band is great.

[turbocamino]

  Hoping to get some of the lost low end pull back with some tuning and not get into the cam swap...also,maybe move the exh cam back a little. Thanks