Mikunis won't idle down

OK, that's the KZ motor? With the roller Cam chain? Pre 80?

web still makes 118's for a kz1000. u can get #'s from them.

here are some # that Larry posted in the past.


Web cam spec’s

---

lift

---

Dur.

---

Dur. ---- Dur. ---

---

[ Ramp Rates ]
Grind .

---

@.020"

---

@.050" - @.100" ---- [20-50] - [20-100] - [50-100]


#45

---

0.415

---

268

---

244

---

220

---

24 --- 48--- 24
110

---

0.395

---

284

---

256

---

228

---

28 --- 56 28
118

---

0.365

---

283

---

246

---

216

---

37 --- 67 30
119 --- 0.384 276 240 210 36 66 30
146 --- 0.420 288 258 232 30 56 26
208 0.408 282 258 233 24 49 25
218 0.418 280 242 218 38 62 24
227 0.383 276 253 228 23 48 25
483 0.395 266 242 216 24 50 26
493 0.415 276 252 229 24 47 23
536 0.378 268 244 218 24 50 26
539 0.400 280 256 230 24 50 26
540 0.384 272 248 222 24 50 26
613 0.381 266 240 218 26 48 22
715 0.408 283 256 228 27 55 28
797 0.410 277 252 224 25 53 28
813 0.388 268 244 218 24 50 26
814 0.402 279 251 223 28 56 28
830 0.383 272 244 217 28 55 27
931 0.380 280 258 232 22 48 26
961 0.400 282 256 228 26 54 28
968 0.386 274 248 220 26 54 28
1002 0.379 274 248 221 26 53 27
1029 0.381 263 240 218 23 45 22
1043 0.400 268 242 216 26 52 26

With that spec sheet, those should be very streetable. But are they installed according to spec? The IN cam would have to be retarded to have a large signal drop.
If it had aftermarket slotted gears on the cams, it could become retarded if the sprocket slips, loose bolts etc.

Perhaps already covered, but has the timing advancer been lubed to help prevent any tendency it might have to hang or stick in the advanced position? If not already done, the timing advancer may need both cleaning and lubing.

Good Fortune!

Its an 1980 engine , has the newer style cam chain and the tensioner rail built into the valve cover.

LOL second hand knowledge stinks, the guy who sold it to me said when it was degreed the intake cam was only 1 degree off on the stock sprocket, or an1/8 of a tooth as he put it so they left that alone the stock exhaust sprocket has been slotted and I assume that the cam has been correctly indexed to work, but this doesn't mean the marks on the sprocket for timing purposes are correct. So waht you are telling me, motorhead, is like in a car if the cam timing is retarded the whole power band is shifted to a higher rpm.

I am assuming we are talking about grind 931 from the list, the ramp rates are greek to me.

931 0.380 280 258 232 22 48 26

280 is advertised duration and 258 is effective duration at.50 so yeah still under 260, if you could explain to me the 22 48 and 26 specs

right now the stock exhaust sprocket timing line is dead on at TDC and the in line in the intake dips just slightly below the level of the top of the head if I advance both of them 1 tooth that will be 7.8 degrees

BTW Thank both You and Mark for hangin with me on this

i thought u said u had 118 grind.
the ramp rates can be used to compare 2 cams of similar advertized lift. the rates describe how quickly it lifts off the seat or ramps up. they are listed above at [20-50] - [20-100] - [50-100].
this is the lift at [.020" to .050"].
i can really only speculate myself.

On your first post you said Web 118: Mark posted the Web Specs:

Webb (#118)

---

0.365

---

283

---

246

---

216

---

37 --- 67 30
If the In cam was closing late, the piston will be traveling up the bore on the compression stroke, which ca push a amount back into the port. This is Reversion. Gives a loss of vacuum, and a Lope at Idle, depending on duration. Those are not big cams if they are indeed the 118 grind. They should be able to run quite well, Idle at 1300, give decent bottom, and hit solid in the mid to upper range. Not a drag race cam, all top and no Bottom/ Idle.
There is a spec for checking the Hi-Vo chain length, I've included the FSM check.
The Hi-Vo chain makes degreeing much harder, as the chain guide is in the cover.
Patton suggests the Advancer cleaning, I'm sure you've done all that, right?
If the timing is hanging it will cause the Idle to hold higher than normal.


Sorry this is the Length, Here.


So if the chain has stretched, or guides worn since the Timing was done, that would retard it some. But enough? Only a degreeing would be able to tell how far, if at all it is off from Web cams spec.

I looked back at the first post, you are right I did say a 118 grind, I was wrong. This is definitely a .380 lift cam from actual measuring with a digital caliper, across the base circle and top to bottom .380 is the difference. the advancer moves freely to me when the engine is at rest, so I haven't taken it off to lube it,(maybe again my mistake), Its a dyna ignition and I used it on the 650 engine, although it came off this engine, for several yrs with no problem. I made a fixture to tension the chain that fits where the old style tensioner bolted in( the 4 holes not used in the head).I guess to eliminate the potential I'll go pull the timing plate and advancer and lube the advancer, any specific oil to use on that?

Specific oil, not really. I use a grease from Bosch for distributors. Cleaning and re-lubing is the important part.
The fixture you made would have to duplicate the valve cover, and chain guide, to hold the chain at the same spot. Otherwise the timing for at least the EX cam would be wrong. I saw an older post, someone put it in one of my old threads, where an old valve cover was cut up.
KZ1P, kzrider.com/forum/2-engine/421264-hi-vo-...ng-tool-or-home-made
Have a look.
If you are in there try to get the Markings off the Cams. 380 lift still dosen't sound bad, but the duration is the biggest equation to drivability.

its closed up at the moment, as I was runnin it this morning, excuse the ignorance once more but where on the shaft do I look and what exactly am I lookin for? got the advancer at the desk as I type, will clean , lube and reinstall. seems free right now.

Makings either Stamped or Engraved in. Usually on the end.

ok, will be gone for a while this time I imagine, torque the advancer in, try that , and then will have to let it cool if the advancer wasn't the problem, so I can take the top off once again TY for all your help, Happy Memorial Day

If it is the advancer you'll know shortly. only other option is to advance the cams a tooth and roll it makin sure nuthin hits. sigh, will look for numbers too . Thanks again