Certain roadways used to have "measured miles" on them designated by signs. The ones in my area were very close to exact distance. Mile markers on Interstates are close but not exact. You need to run your bike thru one of those areas and see what you get, or compare with another vehicle. If your odometer is spot on than your speedo head is the culprit. At that point you have a decision to make, fix the head or leave it and mentally adjust speed. 10% off is quite a bit though.
On all of my bikes, the odometer has been fine. One way to fix the speedometer is to download a gps speed app on your phone, take along pen and paper, find a lonely stretch of road. Ride at a steady speed and compare the speedometer reading to the gps. I think it is easiest to pick several speeds and take several readings at each speed. Something like an indicated 30, 50, 70. Three or four readings at each will help rule out operator error. You can then take the speedometer apart and remove and reposition the needle.
For example, if the speedometer reads 55 at a true 50mph, gently move the needle to an indicated 55 and mark the mechanism with a sharpie. You will need to mark a moving part with an adjacent stationary part. Remove the needle, align the marks and reinstall the needle so it points to 50.
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough
This evening I replaced the points with a Dyna-S ignition. Simple install. Used the double brown plug inside the headlight to get switched power. My only issue is that the wires on the dyna are about 6" shorter than stock. Had to get a little creative to get them to reach.
I also swapped out the spark plug boots with NGK LB05FP.
It could just be me, but my ear-o-meter would swear it idles better.
I also replaced the regulator and rectifier with a Ricks Electric combo unit. Can't seem to find any details on how others wired theirs in. This one is pretty simple. 3 yellow wired to the existing rectifier plug, two reds to positive, 2 greens to ground.
I didn't get as fancy with the install as I probably should have, but I didn't really have everything I should have at the shop either. But once I had the bike apart, I was kinda stuck there until I got things done.
The first photo below shows how it all looks together. The second photo shows what I did with some of the other wiring out of the way. I'm open to feedback if someone tells me I did this wrong, or inefficiently.
PS. Please excuse the El cheapo bullet connectors.
My valve seals have needed replacing from day 1, as I've always had some smoke on downshifts. It's now starting to smoke a bit at idle on occasion too, so I've decided to not wait until winter. It's also a good time to deal with my gooned spark plug holes.
1. Any special tools I'll need other than a valve spring compressor?
2. Should I lap the valves while in there if I'm not cutting the seats?
3. Anything else I should take a good look at when I have the head off?
Wow! Been a while since I posted. Been a busy summer working, planning the wedding (4 days left!) And riding with buddies. I pulled the head a while back and dealt with valve seals. I powered through it in a day, just to prove I could. It was an incredibly long day, and I was completely bagged, but I did it. Stopped short of getting everything synced and running that night tho. I didn't want to push my luck, and felt like I had made my point.
Recently, I started having some really bad surging issues. Actually, I've had surging issues off and on all summer and kept managing to get rid of it by playing with the fuel screws. This time, however, it was really bad. Backfiring hard, sounding like gunfire, scaring small children and grown men alike kinda backfiring. I finally settled on what I'm sure has been my issue all along, which is the choke plunger seals. New choke plungers should be here very soon, if Canada Post ever decides to keep them moving, so I decided to take the opportunity to tear the carburetors apart and bring them to a new local motorbike shop that has a vapor blaster. Carbs came out beautifully, and I almost can't wait until winter to bring him the wheel hubs and motor to do. Almost.
Good luck with the wedding! Looks like the weather will be perfect. Our son just got transferred to the Bow Island wind farm construction, and is living in the Hat, so we're following the weather quite closely. Carbs look really good.
Were the carbs still racked when vapor blasted? Openings & orifices plugged to keep bead out of internal passages? If not, bead is everywhere inside the carbs, slide crank bearings, etc .
Glass bead has a serious tendency to adhere to the workpiece, be it from surface tension, electrostatic attraction or whatever. Even after rinsing in detergent water, bead will often still be present. Sometimes it can be felt as a powdery feeling when running fingers upon the surface.
Bead is almost impossible to see in normal lighting but, bead adhering to a surface can be easily seen as follows:
Place the workpiece in an area of very dim light. Step back a few paces, 6ft. or so. Hold a bright light source such as a good LED flashlight just under eye level & shine it at the workpiece. Any remaining glass bead will reflect the light very brightly.
Best way we've found to remove bead from carb bodies is detergent water in an ultrasonic tank.
slmjim & Z1BEBE
A biker looks at your engine and chrome.
A Rider looks at your odometer and tags.
Sooo... I went drag racing for the first time last night. I'm now fully hooked.
My best reaction time was .001.
My best time was 13.078 at 100.75mph.
I know I can get it into the 12's but the engine is hurt. Cylinder 2 seems it must be scored or something. Entirely possible that valve seals and choke plungers were me just throwing money at the wrong problem, although I certainly don't regret getting those items taken care of.
So now I'll have decisions to make this winter. IF I can get away with a hone and rings I may go that way, but I'm also considering a small big bore kit. My question would be, what is my size limit without swapping out the vm26 carbs? I see Wiseco had a 1045 and 1075 kits. Could those carbs handle 1075, or would I then be looking for some vm28s or larger?
Excellent!! I got hooked 47 years ago! I ran my 72 Suzuki TS 90 Trails bike down the strip!
All the local guys had cars and bikes running! I was 15. Been hooked ever since!
Drags are still cool! Ask Steve Johnson on his new head Suzuki!
And 71yr old Paul Gast running 3.99 ET 1/8 mile’s
Livin in "CheektaVegas, NY
Still have a Kaw! 76 KZ900 Pro-Street.
Went thru 25 of these in 40 yrs.
And The Old Girl, Harley 75 FLH Electra Glide,
Old faithful! Points ign. Bendix Orig. carb.