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TOPIC: cycle head rebluid now the engine turn over slowly

cycle head rebluid now the engine turn over slowly 4 years 10 months ago #516733

  • LarryC
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jeffecor wrote: I had the mechine shop go thou my cycle head and replace three bent valve. I put it back together and the engines turn slowly every be jump the battery off the car.. sometimes turn the engine gets stuck turning and i have to manual turn it. i just rebuild the starter last night everything look good with that.. i was wondering if the start clutch is going out? in side the engine. if you had these problem please help thank you.


Before you get in any deeper, take a deep breath, step back and check a few things over.

1- There's no way to analyze what may be causing the cranking problem based on the information you provided. Jump starting it could be the problem in itself.

If you don't have a leak down tester, get a compression tester. Hold the throttle wide open and crank the motor over. See what the gauge reads on the first snap. You should see 100lbs or darn close.

If you have that on all 4 cylinders, you probably haven't damaged any valves. If it's Zero or very low, pull the valve cover and see what you have for valve lash on the low holes.

If it's a bent valve, generally the lash will be excessive because the valve can't seat. It could also be just a tight valve situation [no lash]. DID YOU CHECK THE LASH AFTER YOU INSTALLED THE FRESHLY REBUILT HEAD?

Not in every case, but many times when an automotive shop does a valve job on one of these old motorcycle heads, the valve installed height isn't taken into consideration. That can lead to tight valves and no compression. It won't lead to a bent valve. Only improper installation of the cam shafts will cause that.

I don't care what Kawasaki KZ engine you have. You want to see at least .004" [.05mm] lash on every valve. Yes it will run with as little at .0005 but that's not what you want to be starting off with on a fresh rebuild.

Check those simple but crucial items before you go further. If compression is good & cam timing is correct, your troubles lie elsewhere. It can be a simple as the main idle screw set too high holding the throttle open too far for a cold start :)

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Larry C.

cycle head rebluid now the engine turn over slowly 4 years 10 months ago #517544

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Well i got it to fire but still have the problem.. I took the starter off and cleaned it again went step by step from the book everything check out with that.. i try to turn the start clutch with my hand it well not turn the one way so i think its ok. wondering if i was off on on the valve height would that cause the engine to have problem trying to turn over. I redid the timing and playing around with it for 30 min got it to fire up and drove it up to 30 mph. I upload a video

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1980 Kawasaki 750 h1 ltd

cycle head rebluid now the engine turn over slowly 4 years 10 months ago #517573

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I would start with getting a good battery because i would think very much of trying to start it like that would burn something up.

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1980 kz1000B4 LTD- 1327cc 9-1 comp
Ported J model head
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And Much Much more- SOLD

2014- ZX14R all stock for now

cycle head rebluid now the engine turn over slowly 4 years 10 months ago #517580

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It has a new battery. Dose the same thing fully charged.

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1980 Kawasaki 750 h1 ltd

cycle head rebluid now the engine turn over slowly 4 years 10 months ago #517628

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With the spark plugs removed, will the starter spin over the engine in a more consistent normal-sounding manner?

Good Fortune! :)

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cycle head rebluid now the engine turn over slowly 4 years 10 months ago #517638

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I just listened/ watched your Vid. That thing is tight alright. Are the Camshaft Bearing Caps installed correctly? This is what may have happened, Camshaft bearing caps mixed up, and installed incorrectly. this causes the cam bearings to be out of round, pinching down on the cam bearing journals.
you should be able to turn the motor over easily by hand with a 17mm wrench at your ignition end of the crankshaft. Don't use the 13mm nut there as it would break off, it only holds the advancer on.
Check your camshaft bearing caps, pull the valve cover and look at them.
Make sure you have Lubricated the cam bearings also, engine oil or assembly lube.
The following user(s) said Thank You: jeffecor

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1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
1979 MAZDA RX7 in the works, 13B...
Last Edit: by Motor Head.

cycle head rebluid now the engine turn over slowly 4 years 10 months ago #517640

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jeffecor wrote: Well i got it to fire but still have the problem.. I took the starter off and cleaned it again went step by step from the book everything check out with that.. i try to turn the start clutch with my hand it well not turn the one way so i think its ok. wondering if i was off on on the valve height would that cause the engine to have problem trying to turn over. I redid the timing and playing around with it for 30 min got it to fire up and drove it up to 30 mph. I upload a video


Throwing sparks next to those carburetors may lead to an interesting dash for the fire extinguisher :ohmy:

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Larry C.

cycle head rebluid now the engine turn over slowly 4 years 10 months ago #517762

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I well take the bear cap off make sure they are round not oval.. if need to replacement them i have some from the other cylinder head.

I need to make sure the distance between the cam shaft and the cap is not to far. because i know the feeler gauge on the exhaust was .006 which fall between .003-.007.

I'm not worried about the spark near the carburetors because that easily put out by covering the hole... I have had it had before.

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1980 Kawasaki 750 h1 ltd

cycle head rebluid now the engine turn over slowly 4 years 9 months ago #517846

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:laugh:

Hate to waste a good fire


Attachments:

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Larry C.

cycle head rebluid now the engine turn over slowly 4 years 9 months ago #517922

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All right its was cam bearing journals two of them are oval that was 3 and 5 caps.

I have the head off the bike right now one of the valve cap is hard to get off i was wondering how to fix that too. Plus I the engine turn's fine with the head off.


I well posts picture of the head Friday.

I did a compression test

1 2 3 4
150psi 150psi 165-170psi 150psi

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1980 Kawasaki 750 h1 ltd
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cycle head rebluid now the engine turn over slowly 4 years 9 months ago #517934

  • Motor Head
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Camshaft bearing caps are numbered, and they are machined to each head. So #1 cap goes on the left, forward, arrow forward. #2 goes on the right, forward arrow forward. #3 goes on the left, rear with he arrow forward, and last the #4 cap goes on the right rear with the arrow forward. Again the caps are machined to the head, if you have 2 heads and mixed up the caps, you will have troubles. Try to be sure that each of the caps are ion the correct location and correct for the head.

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1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
1979 MAZDA RX7 in the works, 13B...

cycle head rebluid now the engine turn over slowly 4 years 9 months ago #517939

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I replaced two of the cap 3 and 5 they was bad not circle.. so i pulled the 3 and 5 for my other head. The head is remarked in the order they go and every thing with a arrow goes forward i get that.. what's your opinion on the valve cap sticking i have a hard time getting the one off.

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1980 Kawasaki 750 h1 ltd

cycle head rebluid now the engine turn over slowly 4 years 9 months ago #517942

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They look bent not weared out.

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1980 Kawasaki 750 h1 ltd

cycle head rebluid now the engine turn over slowly 4 years 9 months ago #517972

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Do you mean the lifter/ cam follower? That's what is stuck? So the pressure of the valve spring is not returning the Lifter in its bore? If so, then more than likely there is dirt etc in the bore for that lifter. If the valve was held open by a stuck lifter, the odds are good that the Piston could have contacted it, thus bending it. Then it won't seal correctly loosing the compression from that cylinder. You will need to get that lifter out, which might be difficult. You may have to weld a fixture to it and use a slide-hammer if its really stuck. Then with the cams still out, rotate that piston to the top, and put some compressed air to that cylinder to see if it holds air pressure. If it sounds like air escaping from the same valve that had the stuck lifter, then the valve is bent and the head will have to be removed, and the valve replaced. Then you can see about the lifter bore, and all the others to make sure the fitment is correct.

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1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
1979 MAZDA RX7 in the works, 13B...

cycle head rebluid now the engine turn over slowly 4 years 9 months ago #517982

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No it not stuck open it just hard to take off valve to take it off i have to use Pliers to get it off i checked the piston no hits on it.. the other come off by magnet easy..

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1980 Kawasaki 750 h1 ltd

cycle head rebluid now the engine turn over slowly 4 years 9 months ago #517985

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OK. So it has a spot where it is hanging up, like a burr or piece of debris. Have you tried a couple of lifters from your other head? Keep in mind there may be a small difference in Height, which may require re-shimming the valve clearance. Or use some fine sand paper on the lifter to polish it a bit, like 800 grit wet/ dry with some light oil on the paper. then clean it really good. It might be hard to clean and polish down in the bore where the lifter goes. But it probably needs this as well.
They should fit, and rotate by hand, with a couple of fingers.

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1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
1979 MAZDA RX7 in the works, 13B...

cycle head rebluid now the engine turn over slowly 4 years 9 months ago #517990

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All right I well try cleaning it up more. I have try from the other head same problem..

I'm going to post pictures or video Friday I well show the head and all the valves plus the top of the pistons too. If want other picture just say..

The cap's I well straight them out so they fit right..

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1980 Kawasaki 750 h1 ltd

cycle head rebluid now the engine turn over slowly 4 years 9 months ago #518067

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Those buckets always fit tight, your problem isnt motor, it sounds like starter to me, you need to hook the wiring up right, and put that battery on a charger, low voltage will cause problems in itself.

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1979 kz 1000 06 katana 750

cycle head rebluid now the engine turn over slowly 4 years 9 months ago #518075

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Hi it was the top end just had it apart and turns fine with the top end off

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1980 Kawasaki 750 h1 ltd

cycle head rebluid now the engine turn over slowly 4 years 9 months ago #518176

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Take the head off.
Take the valves out.
Oil the cam journals and head journals.
Install cams in the empty head, torque to 8 ft.lbs
See if they spin free. They should spin with ease.

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Larry C.

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