Cylinder Prep

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Jeb
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Post by Jeb »

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canyncarvr wrote:
. . . Something to keep in mind: Not everyone agrees with the type of 'break-in' described on CDave's site.

Where to find another approach?

How 'bout HERE!??

:wink:
One more shot at the break-in topic (I'll be doing the swap/break-in this weekend): If I read Eric Gorr's approach, here's what it is from what I can tell -

When you initially start the engine after a rebuild, manipulate the choke to keep the engine rpm relatively low. Once the engine is warm enough to take it off choke, drive the vehicle around on flat hard ground. Keep it under 2/3 throttle for the first 30 minutes.

It goes on to debunk two common myths.

So . . . IS THAT IT? Warm up at low rpms 'till you don't need the choke anymore, drive around on flat ground (no load presumably) under 2/3rds throttle for 30 minutes. No heat cycles.

AM I READING THIS RIGHT?
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

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Jeb
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Post by Jeb »

The OEM piston is a thing of the past - the Wiseco's in place and everything appears to be in great shape. Went OK besides taking forever but my pace was slow/careful and it's been 20 years since I did this. The stock piston looked fine with exception of heavy buildup on top but has now become a plaything for my 6 year old . . .

Anyway, the exhaust valve and sub valves moved pretty freely but I didn't get it all disassembled because I did not get the main rod nut off (how best to do that??). No heavy carbon deposits on the exhaust valve - I could wipe the oil off with my fingers (this IS a fresh bike). There WAS heavy buildup on the piston crown.

I did the Eric Gorr warmup: lowest idle possible until warm enough to run without choke, then rode around for about 30 minutes at < 2/3rds throttle. Then I shut 'er down. I mowed / mulched leaves while it cooled (scored big points for that), so I guess it got one heat cycle before I started really riding her. My son and I rode in the woods for about an hour . . .

NO PROBLEMS!! Great compression and no new noises. I ended up a little richer (??) and ended up dropping the PJ to a 40 with A/S out 2 turns. I didn't get a good chance to see what she would do - it's muddy here and when the midrange kicked in, it was flying mud and leaves. 'Got a feeling it's gonna be great when I can get her to hook up!!

Bottom line: everything went fine, thanks a mil for everyone's feedback and help!! :mrgreen: :supz:
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

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canyncarvr
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Post by canyncarvr »

Good deal!

Re: 'I did not get the main rod nut off ..'

Which fastener are you referring to?

You are aware of the LHT on top of the activating shaft?

'How best' to do that? The KIPS disassembles easily in most cases with basic hand tools and low-moderate force. The 'most cases' goes away when you're dealing with a carbon encrusted mess.

Re: '..with exception of heavy buildup on top'

This is an over-rich indication. Ideally, you should be able to see the 'finish' of the metal on the piston crown (kind'a nubbly) even after years of operation.

Look at the bottom of the OEM piston. Likely there is a good bit of flashing present at mold-joint spots. That weakens the piston..that's why the skirts crack or completely disintegrate.

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Jeb
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Post by Jeb »

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canyncarvr wrote:
. . . Which fastener are you referring to?. . .

You are aware of the LHT on top of the activating shaft?

'How best' to do that? The KIPS disassembles easily in most cases with basic hand tools and low-moderate force. The 'most cases' goes away when you're dealing with a carbon encrusted mess.

Re: '..with exception of heavy buildup on top'

This is an over-rich indication. Ideally, you should be able to see the 'finish' of the metal on the piston crown (kind'a nubbly) even after years of operation.

Look at the bottom of the OEM piston. Likely there is a good bit of flashing present at mold-joint spots. That weakens the piston..that's why the skirts crack or completely disintegrate.
The "nut" is the one at the end of the shaft to which the exhaust valve attaches via the 3mm allen screw, i.e. the shaft that goes side-to-side. Access to the nut is done with a big 'ole flat head screwdriver on the left side of the engine. I couldn't get ahold of this shaft well enough to be comfortable trying to get the nut off.

And the LHT nut was no problem . . . in fact, I would not have been able to remove the cylinder without removing that particular nut !!

10-4 on the overly rich condition. The plug wasn't too pretty either. Nothing I can't fix, though - in fact, I'm looking forward to enhanced performance once I'm jetted correctly. I've got 5 new plugs - sometime this week, perhaps :supz:
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Post by canyncarvr »

Re: 'The "nut" is the one at the end of the shaft to which the exhaust valve attaches via the 3mm allen screw, i.e. the shaft that goes side-to-side.'

Just wrench the thing off. No need to hold the main shaft.

I wouldn't do it with the activation assy still hooked up, but with the cylinder on your bench, it should just come off.

No secret, no secret tool or anything.

Watch the detent ball/spring just under the eccentric on the LH side. The ball usually comes out stuck TO the spring. But..make sure you know where it is before you tip the cylinder back up and hear a 'tink' noise!

You're aware of the manual 'irregularity' that incorrectly IDs the two subport drum shafts?

Doesn't matter now, but FFR and all that..............

..if you know Penton's, you prolly know all of this anyway...........

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Jeb
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Post by Jeb »

I tried a little pressure on that nut but was afraid of messing up the sub valve shafts or the teeth on the main shaft. Wish I would've figured that out - 'didn't get to see the sub valves.

BTW, I watched that fellow with the Penton near tears trying to sort things out, so your bits of wisdom go a LONG ways . . . much obliged !! :prayer:
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canyncarvr
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Post by canyncarvr »

The teeth on the main/subport rods are pretty major. I'm sure you could ruin something if you pushed hard enough..but that nut on the LH side shouldn't be that tight.

Anecdotally: I've NOT 'blocked' the assembly and not had any problem. I've not taken the KIPS apart more than a handful of times though. I NEVER serviced mine on a regular basis. I'd check the movement of the assy by wrenching that nut you're talking about. Moved free and easy, returned to where it was s'posed to easily...why worry? So I didn't.

Maybe you could wedge a piece of wood between the main valve arm and the cylinder. I'd rather not be stressing the cylinder in any case.

You don't want to buy replacement KIPS parts (rods, shafts and drums anyway). They be not cheap!!

Uh...he was trying to sort out WHAT?

KIPS is a piece of cake. Keep in mind what the POINT of the thing is, and it all goes together just fine. It's quite obvious (having the POINT above in mind) if something ain't right. PLUS you get to make it all move before you put the thing together to make sure it's right!

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Jeb
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Post by Jeb »

I could "make it all move" quite easily so I'm good there . . .

On the Penton: What needed sorting out? Gee, that was a long time ago. What memories. I know it was '84 and his bike was like 6-7 years old (I think), metal gas tank, heavy, quite a brute of a bike (it didn't have much snap like us "kids" had on our "zippy" bikes; rather, it had pure brute force), I can still remember how much he bragged about "leading axle" (for all you youngins', that was a new thing at that time) . . .

. . . I can only remember a transmission in pieces on a particular night . . . and lot's of swearing . . . and how us "kids" didn't know squat to help him . . . we loved that guy - called him "pops" . . .

Anyway, I have FAR digressed from the topic at hand, just couldn't help reminiscing.
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Post by Colorado Mike »

As long as we digress... My bike around '80 was a '75 CZ400. yup, a commie pinko weapons-grade piece of coffin-tanked unstartable two stroke smash-mouth bliss. The compression ratio was 12.5:1 and the kickstart lever was something like 4"long. Back then I weighed a whopping 150 lbs. so my friends would delight in seeing me occasionally catapulted over the bars while trying to start Brezhnev's own commie-puppet MX'er. That thing was a tractor though. if you hit the throttle in the lower gears, it would just bury itself to the swingarm.. an emergency brake of sorts.
It also sported phenomenal handling, which back then meant it almost always crashed in a straight line. Kinda wish I had it back. would be hilarious in the vinatage races. Mine was the long-travel model. nearly 6" in the back! Nobody will ever use 6" of travel.. :lol:
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Jeb
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Post by Jeb »

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Colorado Mike wrote:As long as we digress... My bike around '80 was a '75 CZ400. yup, a commie pinko weapons-grade piece of coffin-tanked unstartable two stroke smash-mouth bliss. The compression ratio was 12.5:1 and the kickstart lever was something like 4"long. Back then I weighed a whopping 150 lbs. so my friends would delight in seeing me occasionally catapulted over the bars while trying to start Brezhnev's own commie-puppet MX'er. That thing was a tractor though. if you hit the throttle in the lower gears, it would just bury itself to the swingarm.. an emergency brake of sorts.
It also sported phenomenal handling, which back then meant it almost always crashed in a straight line. Kinda wish I had it back. would be hilarious in the vinatage races. Mine was the long-travel model. nearly 6" in the back! Nobody will ever use 6" of travel.. :lol:
Your story brings back some very cool memories. . . thanks for sharing, CM.

It's amazing how technology has changed things. And not just on the bikes - sheesh, I can jump on a webpage like this and within usually a very short period of time get some good perspective on whatever my issue.
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Post by canyncarvr »

Re: 'Crashed in a straight line'

:grin:

Kind of an odd situation, but mine moved easily for awhile..and that was with the RH subport valve sitting in the pipe!

My low-end wasn't working too well.

:hmm:

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