Hey Guys. Starting a performance upgrade project for my '82 KZ1100A. Last winter I stripped her down and built her how I wanted her cosmetically. Its been a good season, and got a bit left in it, but I've decided I want to give her a little more zip.
My plan currently is to bore out the stock 72 mm sleeves to 74mm MTC pistons. That'll give her 10.5:1 compression.
Before I even get started with that though and while I'm waiting for the weather to turn cold here I'm rebuilding a head I picked up from a salvage yard. Standard Hemi style J head.
The plan with that is to drop a set of .410 lift cams (250 duration if you're interested) from Megacycle. upgrade the springs, oversize the intake valves to 38.6 mm and exhaust valves to 33 mm. Top it all off with a nice port job from Cavanaugh and somewhere near the end slap some flatside rs carbs on her. possibly a couple ofther upgrades while I've got it apart. Welded crank and HD cam chain and all. We'll see where she takes me!
Already Started in on the head. Took her apart and Cleaned up the combustion chambers with a rotary tool and brass wire brush.
btw if you go to disassemble one of these, I'd highly reccomend the 60 dollar valve spring compressor tool from Z1. Made it a breeze.
Been out of it for a while but I've started back at it and I figured I'd thrown an update in here.
I've blasted and decked the head, shes basically spotless now and later today I'm shipping it off to Larry to cut the new valve seats and do some port work for me!
Back again after a long bout of being in and out of town for work. Got my cylinders bored, cleaned and resurfaced. Set of MTC 10.5:1 pistons to match will bring my displacement up to 1135. Gaskets and few other nifty parts like APE manual tensioner and APE cylinder studs arrive tomorrow to begin reassembly. Just waiting on Larry to get to my head done and I'll be able to take this monster out on the streets pretty soon!
Got the pistons in! I used the reverse method and put pistons in the cylinders then pushed them down and slid the wrist pins in the pistons. Seemed easier, but what do I know? MTC instructions say to leave piston rings dry because 'it helps seal better' but idk if I'm a believer of all that jazz so I did wipe a bit of assembly lube on the cyl walls. We'll see how it goes I guess!
Everything is in place now. Just waiting on the head! Getting antsy, riding season is here in Kansas! In the mean time I'm going to take off my carbs and install a stage 3 Dynajet kit. Should help feed her a little better while I'm running the bs carbs.
Started to get into the carbs and install the jet kit. Figured as long as I'm there I might as well strip and repaint! Used VHT engine the first time and I didn't like how easy it chipped. Used 2k clear coat on a set I rebuilt for my CX500 build and they turned out really well so I'm gonna go that direction. Right now they're just stripped and sand blasted and going through a final bath in the ultrasonic. Next up paint, rebuild and hopefully she'll be running like a brand new machine on these bad boys with that jet kit installed!
Finished the carbs up! At least for now. Had a couple hiccups. First I was doing reassembly and noticed I was missing one of the aluminum plugs thats in the float bowl area so I had to go turn one down on the lathe real quick. Almost done and I notice that I can't find my throttle bracket (the part that holds the cable sleeve in place). SOB.
I'd prefer the original style piece so I'm hoping I can find one in the next week or so, if not Ill just fork over the 35 bucks and get one from partzilla that goes to the later police models cause they're not discontinued like the one I want. Not a huge deal though.
That big old hole is where the plug I lost goes:
Old and new!:
AAaaaand here's the bracket I seem to have lost somehow:
And finally the (mostly) finished carbs! Jet kit installed. Just need my head from Larry, a vacuum sync and some seat dyno tuning!
Well guys, here's the update:
Still waiting on getting my head back from Larry, so I went ahead and did up the other one I had laying around so I won't miss out on riding season. Figured I might as well set my rings and work out any issues before that ported head arrives.
First I assembled and lapped the valves (had to assemble twice cause I didn't know the springs are directional until I was skimming through my manual)
Then I bought some ebay stock cams. Looks like they came out of an '82 1000 K or M model based on the lift. Seller tried to tell me it was a B model, which would make them GPZ cams but theres no way thats right. anyway, I digress:
Got the head put on next and checked all my clearances. Torqued down with some APE HD cylinder studs and nuts. Sorry I should have taken more pictures, but I was trying to finish before bed time
Then got her all timed in and got the cams set:
After cranking by had a few times to check for smooth operation I buttoned her up and stuck everything back on and I was ready for start up and the first heat cycle!
I know there's several schools of thought on the break in process so I've kind of been doing a mash up of the two because I can see valid points on both sides.
Hopefully I'm not just muffing things up.
For my first heat cycle and break in period I filled her up with Rotella T4 15w-40. I only had a bit of permatex engine assembly lube wiped on the cylinders (stuff is like snot) the MTC instructions say to run it dry to set the rings but idk about all that seems aweful rough so I met in the middle with a bit of lube. Anyways, started her up and it only took a couple cranks! she screamed to life and I used the idle speed screw to set her at about 2500 rpm and let her heat up for about 15-20 min or so then let her cool down for a couple hours before a retourque and check on eveything, including valve lash. Then I took her out for a quick 20 min ride keeping her around 3k or so rpm engine breaking a lot and all that, no steady throttle. Once I got back I did a quick carb sync and turned in.
Next day I got in 75 mi for my first break in period and changed oil back to good ol Kawi 10w40. Shortly after that I took her out and gave it a little more throttle took it up to about 6k on the highway and I heard a horrible chatter that sounds like its coming from the valve train. Greaaaaat.
So I go back home and do some research. At first I'm thinking I didn't set the manual tensioner tight enough so I go through that a few more times, but if it was chain noise it'd be there all the time right? So I set it and then double checked my ig timing with a light (read on here it can cause valve chatter at higher rpm).
Go back out and still the same.
It only happens when I open the throttle to about half way, in higher rpms and cuts out when I let off. Not present anywhere else. I pushed it a little and it seems to go away a bit if I keep on the throttle but it's till there. Doesn't feel like any huge power loss or anything when it happens. There's no excessive carbon build up on the pistons and I'm running 93 gas so I don't think it's detonation, but I'm just a rookie and from what I've read on here my higher compression could cause such things.
Anyone got any ideas as to what it might be?
Tonight I'm going home to take the valve cover off and look for any tell tale signs of chatter or wear and maybe I can figure it out. Also going to check under my stator cover and make sure nothing is loose in there, I've heard of them coming loose.
By the way, anyone want to tell me about how much play their cam chain has after they tightened it with a manual tensioner? I've followed the directions to a T, but I'm a visual guy and I'd love to be able to compare what I've got going on to what someone has going on with theirs that they know is set properly.
Well I did some investigating last night and it looks like a couple of my threads got pulled out on my cam cap bolts. My guess is that's where the noise is coming from. Seems strange though, when I checked my valve lash everything seemed in order and all were torqued down to 100 in lbs. FSM that I have gave 12 ft lbs which seems excessive (I know this has been discussed at length on here) some people say 70 in lbs some people just barely tighten by hand. Anyways, tonight Ill be helicoiling a couple threads for that and hopefully that cures my chatter issues!
I also went through my manual tensioner again and came out with the same tension so I'm pretty sure I got it right. Has roughly half inch of play with all the slack pulled up between the two cams. Too loose? too tight?
Never use a torque wrench on 6mm bolts they will strip out. Most people don't know how to use a torque wrench which makes the problem worse. They also tend to buy a cheap torque wrench which isnt even close to being calibrated correctly. Tighten them by hand using a short 1/4" ratchet, you'll feel it when it's tight.
What type of allen head screws are those in the cam caps?
I just finished an overhaul of a KZ900 engine for a customer. Every cam cap bolt hole was stripped, the last "mechanic" who worked on it driiled holes all the way thru the head where he could and then installed long bolts with nuts. For the holes he couldn't drill thru he simply installed the bolts back in with large amounts of epoxy. Surprisingly it was running when I got it.
These engines are air cooled I read you let your fresh engine idle for 15 to 20 minutes at 2500 rpm? Please tell me you didn't do that.
Admittedly my in lb torque wrench is cheap, though I figured calibration wouldn't need to be spot on since I was so far from the FSM spec. They torqued down fine just apparently didn't have good enough threads to hold once they got some actual stress on them. Lesson learned I suppose.
They are 18-8 ss allen head bolts.
Hah that sounds like a jury-rigged engine right there.
I did, though in all honesty it probably wasn't that long. I didn't time it, but it hit 210 at the valve cover when I shut it off. If it's overheating you're worried about I had a big ol industrial fan pushing air over her and watched the temp with an ir thermometer. Just a full heat cycle to torque the head nuts down the rest of the way.
Overheating and thats hard on a new set of rings. New rings don't like heat and sitting there at 2500 rpm is a good way to glaze the cylinder up so the rings never bed in correctly. Bedding in new rings and pistons requires high cylinder pressure and most of the breakin on a rebuilt engine occurs in the first 10 to 20 minutes of engine start so sitting there at 2500 rpms at low cylinder pressures the rings simply glaze the cylinder walls.