- Posts: 27
- Thank you received: 2
1979 KZ650 - Baby Steps to a Running Bike
- CMcAuliffe
- Topic Author
- Offline
- User
Bought the bike for a project. The Electrical forum here helped me to get proper spark (thanks, guys), but the use of transparent fuel lines proved I wasn't getting enough fuel during cranking, and what there was of it was filthy. Carbs are off and I'm rebuilding them. One at a time they are being disassembled, spending 12 hours+ in a Gunk carb cleaner bucket, brushed with a toothbrush where I can reach, rinsed in warm water, and blown out with compressed air through every orifice I can find.
Question: Is it worth it to get an ultrasonic cleaner? Some videos I've seen of before and after show they don't look any better than what I got with the dip, which doesn't give me a ton of confidence they are superior in cleaning out the insides any better. I know I also have to watch what I use for a cleaning agent, since some can attack the aluminum. It looks like I'll have to spend $150-$200 for a cleaner with a heater and some cleaning agent. Would I have a use for it beyond the carbs? Beyond the bike? I'd need to justify the cost to the wifey...
Also: while trying to get it to start, I performed compression and leak down tests. For compression, cylinders 1-4 read: 145, 120, 140, and barely over 30psi. So #4 is a dead cylinder.
On the leak down test, I didn't exactly have the motor at TDC. I just rotated it until the pressure in the cylinder started to increase. I would rotate through the cycle a couple of times to try to get accurate/consistent readings. This might not be the superior way of doing it, since I think my loss percentage readings were a little wonky in relation to my compression test results. Cylinder 1, which had the best compression, leaked the most at 65%, mostly through the exhaust. 2 was at 45%, mostly through the rings. 3 was 35%, mostly through the rings. And 4 was at 60%, mostly through the exhaust. So, while I'm sure there's carbon on those exhaust valves, I'm pretty sure those cylinders need attention, too. The odometer reads 28,300. I'll bet that's at least 128,300.
Question: Once I get the carbs as put together/functioning as best I can on the bench, should I put them aside and then go straight to a top-end rebuild? That's where I think I'm headed. Everything needs attention, I'm just trying to only do a little at a time so I don't create a parts farm.
Thanks,
Chris
Please Log in or Create an account to join the conversation.
- Mikaw
- Offline
- Sustaining Member
- Posts: 5007
- Thank you received: 1918
As far as the ultrasonic cleaner that’s the similar question to asking what is the best oil. Everyone will have their own opinion as to what works best for them. I have never used one so I have no idea how the results are. I have good luck with soaking in Barrymans carb dip, and then spraying and cleaning everything out with brake cleaner.
1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.
Please Log in or Create an account to join the conversation.
- Skidmark
- Offline
- User
- Posts: 1071
- Thank you received: 265
Retired gearhead
'81 KZ-750 E2
'87 Suzuki Savage 650 Street Tracker (lost in the shop fire)
Please Log in or Create an account to join the conversation.
- Warren3200gt
- Offline
- User
- Posts: 1518
- Thank you received: 717
135 - 140psi is not to bad as I assume they are cold readings. Probably would equate to 150+ on a warm engine which is how it should be done with the throttle fully open or better still no carbs fitted. . One low cylinder is likely a mis read!/sticky ring / valve and needs checking again.
As Skidmark said, old dirty fuel is pointless trying to use and will mess your efforts with the carbs instantly.
Please Log in or Create an account to join the conversation.
- Nessism
- Offline
- Sustaining Member
- Posts: 7549
- Thank you received: 2863
I recommend shooting carb dip spray though all the passages and making sure none are blocked.
Regarding the low compression, did you adjust the valves yet? Chances are fair that #4 has tight valves causing compression loss. Soaking in MMO is a good call. Adjust the valves and put some good hard miles on the engine. Only then will you know the true compression situation.
Please Log in or Create an account to join the conversation.
- CMcAuliffe
- Topic Author
- Offline
- User
- Posts: 27
- Thank you received: 2
The petcock filter looked clear to me, but while I await parts for the carbs I'll address the tank, which has some surface inside.
Please Log in or Create an account to join the conversation.
- Nessism
- Offline
- Sustaining Member
- Posts: 7549
- Thank you received: 2863
Thanks for the input. I've put some MMO in the cylinders and in the valley where the cams sit and will let it soak a day or two.
The petcock filter looked clear to me, but while I await parts for the carbs I'll address the tank, which has some surface inside.
Be sure to adjust the valves before trying to start the bike again. If the valves are hanging open you will just cause more damage by running it further.
Please Log in or Create an account to join the conversation.
- TexasKZ
- Away
- Platinum Member
- Posts: 7592
- Thank you received: 2243
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough
Please Log in or Create an account to join the conversation.
- loudhvx
- Offline
- KZr Legend
- Posts: 10868
- Thank you received: 1616
For some reason that link doesn't work for me.Here is a good way to insure a really clean fuel tank.
www.kwick.biz/how-to-flush-your-fuel-tank/
"This site can’t be reached"
1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.
Please Log in or Create an account to join the conversation.
- TexasKZ
- Away
- Platinum Member
- Posts: 7592
- Thank you received: 2243
Weird. It works fine for me. Here is the home page address for that site.
For some reason that link doesn't work for me.Here is a good way to insure a really clean fuel tank.
www.kwick.biz/how-to-flush-your-fuel-tank/
"This site can’t be reached"
www.kwick.biz
Go to Kwick’s Corner and scroll down a bit.
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough
Please Log in or Create an account to join the conversation.
- loudhvx
- Offline
- KZr Legend
- Posts: 10868
- Thank you received: 1616
1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.
Please Log in or Create an account to join the conversation.
- TexasKZ
- Away
- Platinum Member
- Posts: 7592
- Thank you received: 2243
Solar flares? Global warming? Midget zombie apocalypse?Thanks. That link works now. Maybe it was down briefly.
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough
Please Log in or Create an account to join the conversation.