Power tuning a Honda Z600, the next frontier....

[Mark P Hatten]

During my Z600 power improvement quest I noticed my timing chain is loose and probably stretched. The chain looks good, but seems to have a lot of play. The timing marks line up, but not perfectly. With the small belt pulley notch under the battery lined up on "T" , the upper cam chain gear horizontal scribe is almost flat, with the tiny notch in the end of the cam near the tach drive is slightly forward ....just a tad toward the core support. I know this tiny amount can make a big performance reduction. It's probabably 4-8* off. Not as much as one tooth off, but almost.
Has anyone tried to just remove one chain link to shorten and tighten the chain and bring it back into perfect alignment? Seems like it would work.
Mark Portland Or.
www.mphspecialties.com
To: anzhonda600owners@yahoogroups.com CC: anzhonda600owners@yahoogroups.com From: egeiger@...
Date: Tue, 15 Jan 2013 21:04:30 +0000 Subject: Re: [anzhonda600owners] Power tuning a Honda Z600
Can you please explain a little further about " Since then,  I now use an indicator to register the cam to the crank.  Moving the chain 1 or 2 teeth in each direction made a noticeable difference in the performance of the engine."
I'm curious about this method.
 My T on the crank pulley and notch on the cam are matched almost perfect maybe 1/16th an inch toward the firewall .  I've also always used a test light to set the timing via the vacuum advance.   I also feel like my car is a little low on power since I rebuilt the engine.  So I'd like to know more about what you're method is.
Thanks
Eric J. Geiger
---------------------------------------
PRG Nocturne
XXX-XXX-XXXX phone
XXX-XXX-XXXX fax
XXX-XXX-XXXX mobile
egeiger@...
www.prgnocturne.com

On Jan 15, 2013, at 3:46 PM, "
goinhm@...
" wrote:
Hi Mark,
I'm coming into this conversation late and I have seen the other comments.  Here is some added info;
1.  The Honda Inc spec on a stock 1972 USA coupe indicates it should do the 1/4 mile in 22.3 seconds and have a speed of 57 mph.  This measurement is at sea level ..... which is about where you are in Portland.
2.  Your compression reading of 147 psi is a bit low.  It should be in the 160 to 165 psi range for a new (or rebuilt) engine.
3.  The registration of the cam to the crank is important.  I used to align the "witness" mark on the cam sprocket and register it to the notch on the pulley when it was at "T" on the casing.  And then one day I was noticing my 1/4 mile time wasn't correct on a engine I had rebuilt (when I drove to work,  I used to time myself on a road I would enter which had the 55 mph speed marker at a 1/4 mile distance from where I entered).  I found that I had to move the chain on the sprocket 1 or 2 teeth.   Since then, I now use an indicator to register the cam to the crank.  Moving the chain 1 or 2 teeth in each direction made a noticeable difference in the performance of the engine.
good luck,
Dale
> I've been tuning for speed and power on my 1972 600cc 4 stroke Honda Z600 hot rod. I can now go 47 mph. in 1/4 mile, up from 43 mph. last week but, it still seems lethargic. I got a slight miss to go away, but am disappointed with low top speed > power. Here's the back story. Fresh 20-50 wt. oil and filter. New hot NGK #6 plugs, new 7mm wires, new NGK 90* ends, plugs are clean after hard run, swapped, tested, ignition coils, new NOS points gapped correct, new condenser, vac. and mechanical advance > checked and cleaned and seem good. Timing is slightly advanced. 147 psi. compression on both cylinders, timing chain is sloppy but timing marks line up. Idles smooth, revs up good. No backfires, no misses. Smooth but low power. Redlines at 6500-6700 rpm's > no problem. Tried 2 carburetors, one old style, one new style, both are clean, accelerator pump works in both, float levels correct. Both carbs act the same. 2 psi. fuel pressure, clean fuel. All new exhaust gaskets, no leaks, exhau st is not plugged. Tires > are new and inflated to 40 psi., alignment is perfect, brakes do not drag. Can push car with two fingers on level surface.
> My Subaru 360 could run rings around this slug with half the displacement. It just don't seem right.
> Most 600 owners say their cars will go 70 mph. Maybe,..... with a 5 mile head start!.
> What am I missing here?
> How does one increase the jet size? Do you file the taper on the carb slide plunger needle?
> I know my hood scoop does not aid aerodynamics...but, this much?
> Help please.
> https://www.youtube.com/watch?v=tyW8KQeYsfg
> Mark
> Portland Or.
> www.mphspecialties.com

[richmccolman]

Three words, Mark: DON'T DO IT!
When I owned my N600 back in the late '70s, I had a loose timing chain that had jumped a a link or two. (This was the second time the car had jumped time in roughly 20,000 miles, due, I figured out later, to me driving the car past red-line speed. [Since there's no tach in the sedan, this fact was less obvious, especially to a novice driver at the time.] The first time the chain had jumped, it jumped so far that it bent valves, so that time I did a major engine tear-down to replace the chain. This second time I wanted to avoid doing a major engine tear-down, so having caught the chain before it jumped enough to bend valves, I figured I could avoid that.) My dad came up with the same idea that you're suggesting -- remove a single link from the chain.
Well, we removed the link, but found that doing so made the chain so tight that we had to use quite a lot of force to pry the camshaft back into position in order to get the camshaft holders back into place in the camshaft housing. The chain was super-tight. Anyway, as soon as we cranked up the engine we started hearing metallic popping sounds, so after a few seconds we stopped the engine, removed the valve cover, and discovered much to our horror that the excessive tension on the chain had broken a bunch of teeth off of the camshaft!
Needless to say, I ended up having to do the full engine teardown after all, especially given that I had a bunch of camshaft teeth down in the bottom of the engine crankcase.
What this taught me --the hard way -- was that when the chain gets stretched, it MUST BE REPLACED!
However, there is a way to do that without doing a complete engine tear-down. The key is to get a new chain -- in this case a split chain -- one end of which you thread through the engine, then attach a master link to the two ends and peen the rivets completing the loop.
To do this, you have to remove the chain tensioner and the camshaft, break or cut the old chain (making sure to not get bits of metal in the engine, and also making sure not to drop the cut chain down in the engine -- in fact, you need to keep both ends of the old chain reasonably tight on the crank sprocket throughout the process), then bend a piece of stiff wire to link one end of the old chain to one end of the new chain. Then, keeping the chain under enough upward pressure on both ends to keep it from falling off the crankshaft sprocket, turn the engine over by hand until the old chain pulls the new chain down, around the crank sprocket, and back up through the engine to the camshaft housing on the other side. Once you've done all that -- continuing to apply upward tension on both ends of the new chain, disconnect the wire linking the old and new chains, and then peen the master link to the two ends of the new chain, creating a continuous loop of chain. Then put everything back together (synching up the crankshaft and camshaft, of course), and you've successfully installed a new chain while avoiding a major engine tear-down! It may be best to do this with an assistant, since the procedure works best with more than two hands, probably.
You can get a visualization of a variant on this technique in this video of a one-cylinder Honda motorbike cam chain. The fellow in this video used a MIG welder on his bike's new chain, but that's because he bought a non-split replacement chain:
http://www.youtube.com/watch?v=IkSl0ZUDnZc
Bruce Whiting sells split chains for 600 cars complete with a matching master link on his web site:
http://www.honda600carparts.com/engine.html
Hope this helps.
Richard

--- In
2cylinderhondas@yahoogroups.com
, Mark P Hatten wrote:
> During my Z600 power improvement quest I noticed my timing chain is loose and probably stretched. The chain looks good, but seems to have a lot of play. The timing marks line up, but not perfectly. With the small belt pulley notch under the battery lined up on "T" , the upper cam chain gear horizontal scribe is almost flat, with the tiny notch in the end of the cam near the tach drive is slightly forward ....just a tad toward the core support. I know this tiny amount can make a big performance reduction. It's probabably 4-8* off. Not as much as one tooth off, but almost. Has anyone tried to just remove one chain link to shorten and tighten the chain and bring it back into perfect alignment? Seems like it would work. MarkPortland Or.
> www.mphspecialties.com
> To:
anzhonda600owners@yahoogroups.com
> CC:
anzhonda600owners@yahoogroups.com
> From: egeiger@...
> Date: Tue, 15 Jan 2013 21:04:30 +0000
> Subject: Re: [anzhonda600owners] Power tuning a Honda Z600
> Can you please explain a little further about "Since
> then, I now use an indicator to register the cam to the crank. Moving the chain 1 or 2 teeth in each direction made a noticeable difference in the performance of the engine."
> I'm curious about this method.
> My T on the crank pulley and notch on the cam are matched almost perfect maybe 1/16th an inch toward the firewall . I've also always used a test light to set the timing via the vacuum advance. I also feel like my car is a little low on power since I rebuilt
> the engine. So I'd like to know more about what you're method is.
> Thanks
> Eric J. Geiger
> ---------------------------------------
> PRG Nocturne
> XXX-XXX-XXXX phone
> XXX-XXX-XXXX fax
> XXX-XXX-XXXX mobile
> egeiger@...
> www.prgnocturne.com
> On Jan 15, 2013, at 3:46 PM, "goinhm@..." wrote:
> Hi Mark,
> I'm coming into this conversation late and I have seen the other comments. Here is some added info;
> 1. The Honda Inc spec on a stock 1972 USA coupe indicates it should do the 1/4 mile in 22.3 seconds and have a speed of 57 mph. This measurement is at sea level ..... which is about where you are in Portland.
> 2. Your compression reading of 147 psi is a bit low. It should be in the 160 to 165 psi range for a new (or rebuilt) engine.
> 3. The registration of the cam to the crank is important. I used to align the "witness" mark on the cam sprocket and register it to the notch on the pulley when it was at "T" on the casing. And then one day I was noticing my 1/4 mile time wasn't correct
> on a engine I had rebuilt (when I drove to work, I used to time myself on a road I would enter which had the 55 mph speed marker at a 1/4 mile distance from where I entered). I found that I had to move the chain on the sprocket 1 or 2 teeth. Since then,
> I now use an indicator to register the cam to the crank. Moving the chain 1 or 2 teeth in each direction made a noticeable difference in the performance of the engine.
> good luck,
> Dale
> I've been tuning for speed and power on my 1972 600cc 4 stroke Honda Z600 hot rod. I can now go 47 mph. in 1/4 mile, up from 43 mph. last week but, it still seems lethargic. I got a slight miss to go away, but am disappointed with low top speed
> power. Here's the back story. Fresh 20-50 wt. oil and filter. New hot NGK #6 plugs, new 7mm wires, new NGK 90* ends, plugs are clean after hard run, swapped, tested, ignition coils, new NOS points gapped correct, new condenser, vac. and mechanical advance
> checked and cleaned and seem good. Timing is slightly advanced. 147 psi. compression on both cylinders, timing chain is sloppy but timing marks line up. Idles smooth, revs up good. No backfires, no misses. Smooth but low power. Redlines at 6500-6700 rpm's
> no problem. Tried 2 carburetors, one old style, one new style, both are clean, accelerator pump works in both, float levels correct. Both carbs act the same. 2 psi. fuel pressure, clean fuel. All new exhaust gaskets, no leaks, exhau st is not plugged. Tires
> are new and inflated to 40 psi., alignment is perfect, brakes do not drag. Can push car with two fingers on level surface.
> My Subaru 360 could run rings around this slug with half the displacement. It just don't seem right.
> Most 600 owners say their cars will go 70 mph. Maybe,..... with a 5 mile head start!.
> What am I missing here?
> How does one increase the jet size? Do you file the taper on the carb slide plunger needle?
> I know my hood scoop does not aid aerodynamics...but, this much?
> Help please.
https://www.youtube.com/watch?v=tyW8KQeYsfg
> Mark
> Portland Or.
> www.mphspecialties.com

[David Baer]

Mark:� are you sure the throttle plate is level at W.O.T. and the choke plate has completely returned to normal position.� I'd check them before tear down...maybe an easy fix.

On Thu, Jan 17, 2013 at 6:59 PM, Mark P Hatten
�
> During my Z600 power improvement quest I noticed my timing chain is loose and probably stretched. The chain looks good, but seems to have a lot of play.�The timing marks line up, but not perfectly. With the small belt pulley notch under the battery lined up on "T"�, the upper cam chain gear horizontal scribe is almost flat, with the tiny notch in the end of the cam near the tach drive is slightly forward ....just a tad toward the core support. I know this tiny amount can make a big performance reduction. It's probabably 4-8* off. Not as much as one tooth off,�but almost.
> �
> Has anyone tried to just remove one chain link to shorten and tighten the chain and bring it back into perfect alignment? Seems like it would work.
> �
> Mark
> Portland Or.
> www.mphspecialties.com
> �
> To:
> anzhonda600owners@yahoogroups.com
> CC:
> anzhonda600owners@yahoogroups.com
> From:
> egeiger@...
> Date: Tue, 15 Jan 2013 21:04:30 +0000
> Subject: Re: [anzhonda600owners] Power tuning a Honda Z600
> �
> Can you please explain a little further about "
> Since
> then,� I now use an indicator to register the cam to the crank.� Moving the chain 1 or 2 teeth in each direction made a noticeable difference in the performance of the engine."
> I'm curious about this method.
> �My T on the crank pulley and notch on the cam are matched almost perfect maybe 1/16th an inch toward the firewall . �I've also always used a test light to set the timing via the vacuum advance. � I also feel like my car is a little low on power since I rebuilt > the engine. �So I'd like to know more about what you're method is.�
> Thanks�
> Eric J. Geiger
> ---------------------------------------
> PRG Nocturne
> XXX-XXX-XXXX
> phone
> XXX-XXX-XXXX
> fax
> XXX-XXX-XXXX
> mobile
> egeiger@...
> www.prgnocturne.com
> On Jan 15, 2013, at 3:46 PM, "
> goinhm@...
> " goinhm@...
> > wrote:
> > �
> > Hi Mark,
> > �
> > �� I'm coming into this conversation late and I have seen the other comments.� Here is some added info;
> > �
> > 1.� The Honda Inc spec on�a stock 1972 USA�coupe indicates it should do the 1/4 mile in 22.3 seconds and have a speed of 57 mph.� This measurement is at sea level ..... which is about where you are in Portland.��
> > �
> > 2.� Your compression reading of 147 psi is a bit low.� It should be in the 160 to 165 psi range�for a new (or rebuilt) engine.
> > �
> > 3.� The registration of the cam to the crank is important.� I used to�align the "witness" mark on the cam sprocket and register it to the notch on the pulley when it was at "T" on the casing.� And then one day I was noticing my 1/4 mile time wasn't correct > > on a engine I had rebuilt (when I drove to work,� I used to time myself on a road I would enter which had the 55 mph speed marker at a 1/4 mile distance from where I entered).��I found that I had to move the chain on the sprocket 1 or 2 teeth.�� Since then,� > > I now use an indicator to register the cam to the crank.� Moving the chain 1 or 2 teeth in each direction made a noticeable difference in the performance of the engine.
> > �
> > good luck,
> > Dale
> > �
> > �
> > > �
> > > I've been tuning for speed and power on my 1972 600cc 4 stroke Honda Z600 hot rod. I can now go 47 mph. in 1/4 mile, up from 43 mph. last week but, it still seems lethargic. I got a slight miss to go away, but am disappointed with low top speed > > > power. Here's the back story. Fresh 20-50 wt. oil and filter. New hot NGK #6 plugs, new 7mm wires, new NGK 90* ends, plugs are clean after hard run, swapped, tested, ignition coils, new NOS points gapped correct, new condenser, vac. and mechanical advance > > > checked and cleaned and seem good. Timing is slightly advanced. 147 psi. compression on both cylinders, timing chain is sloppy but timing marks line up. Idles smooth, revs up good. No backfires, no misses. Smooth but low power. Redlines at 6500-6700 rpm's > > > no problem. Tried 2 carburetors, one old style, one new style, both are clean, accelerator pump works in both, float levels correct. Both carbs act the same. 2 psi. fuel pressure, clean fuel. All new exhaust gaskets, no leaks, exhau st is not plugged. Tires > > > are new and inflated to 40 psi., alignment is perfect, brakes do not drag. Can push car with two fingers on level surface.
> > > My Subaru 360 could run rings around this slug with half the displacement. It just don't seem right.
> > > Most 600 owners say their cars will go 70 mph. Maybe,..... with a 5 mile head start!.
> > > What am I missing here?
> > > How does one increase the jet size? Do you file the taper on the carb slide plunger needle?
> > > I know my hood scoop does not aid aerodynamics...but, this much?
> > > �
> > > �
> > > Help please.
> > > �
> > > �
> > > https://www.youtube.com/watch?v=tyW8KQeYsfg
> > > �
> > > �
> > > Mark
> > > Portland Or.
> > > www.mphspecialties.com
--
David F. Baer
469 Ena Rd., Apt. #1311
Honolulu, HI 96815
Cell:� XXX-XXX-XXXX