[SOLVED]Engine break-in....stalling...overheating?

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[SOLVED]Engine break-in....stalling...overheating?

01 Jul 2011 16:25 - 29 Jul 2011 01:16
#460495
Dear kzrider members,
My recently built gpz 750 (now 810cc bored, wiseco kit) is stalling at stop...but wait

Yesterday did my carb sync everything was great ... good stable idle at 1100 rpm mixture was a bit rich on the pilots (colortune showed yellow flame on all cyl.) so i've turn in a little bit the 4 pilot screws and it was good.


Today is my first ride with the new pistons and valve job that has been done to the head...
Few minutes (15-20mins) of riding where perfect good idle at stop... then gone to the highway did a series of WOT at 5 min interval. Throttle response was perfect... no flat spot! Then when i exit the highway and start to run in city.

Few red lights after that, engine died when came to a stop! (first gear fully pulled clutch) Started again in panic then had to play with the throttle to prevent it from dying!

Also when i played with the idle adjustment I've noticed the engine looked abnormally hot! i burned myself on the clutch cover !

Is the bigger bore which can cause overheating ? Is the bike really overheating ... how do we know ??

best regards,
laurent
1982 KZ810-R1 GPZ with hindle 4-into-1 pipe
Last edit: 29 Jul 2011 01:16 by ELCouz.

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Re: Engine break-in....stalling at stop...overheating?

01 Jul 2011 16:59
#460498
Valve tolerance closing up? Do you have a laser temp-gun to get a read on the pipes and head? Nice thing to have and Harbor sells one pretty cheap.
1979 KZ1000E1 SOLD!
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Re: Engine break-in....stalling at stop...overheating?

01 Jul 2011 17:20
#460501
Valve tolerance closing up?
Maybe i have an exhaust valve (#4) which has 0.08mm of clearance (borderline specs 0.08-0.018mm) with a 2.05mm shim!!
Do you have a laser temp-gun to get a read on the pipes and head?

Yes i had...it broke today while trying to check temp... gonna buy a new one now and post temp!

brb, purchasing it!!!

regards,
laurent
1982 KZ810-R1 GPZ with hindle 4-into-1 pipe

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Re: Engine break-in....stalling at stop...overheating?

01 Jul 2011 17:38
#460503
Some may not agree with this but anyways - Retard your timing a couple of degrees from stock, so that Full advance is around 36-38 degrees.
You'll be pleasantly surprised that it will actually be faster, and everything will run cooler.

Check that jetting and make sure your nott too lean in the cruise position - use the colortune:



Good luck.

B)
Motorcycle Shop Owner/Operator

79 Kawie Z1000 LTD
81 Kawie Z1000 CSR
83 Honda VT750C A
85 Kawie GPZ900 A2
86 Zukie GS1150 EG
93 Yamie XV1100 E
Lucky to have rolled many old bikes through my doors ;)

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Re: Engine break-in....stalling at stop...overheating?

01 Jul 2011 17:54 - 01 Jul 2011 18:09
#460510
Some may not agree with this but anyways - Retard your timing a couple of degrees from stock, so that Full advance is around 36-38 degrees.
You'll be pleasantly surprised that it will actually be faster, and everything will run cooler.

Head has been milled, this retard timing normally but lacking proper tools (to check cam timing) and money :(

Damn store are closed today (canada's day) :( so no IR temp sensor !

For the colortune...my neighbors are going hardcore with the revving lately so I've only checked with colortune idle to 3000 rpm max! (relying on sparks plugs reading for WOT mixture...dark(dry not wet) around plugs and grayish on the electrode insulator...all of them are identical)

Also i cannot run on WOT on the highway while checking colortune that would be DEADLY crazy ! :woohoo:

No access to dyno too :(

thanks for the colortune chart but it's too small to read (picture) i will check on the net!

regards,
laurent
1982 KZ810-R1 GPZ with hindle 4-into-1 pipe
Last edit: 01 Jul 2011 18:09 by ELCouz.

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Re: Engine break-in....stalling at stop...overheating?

01 Jul 2011 18:01
#460513
btw, will adding clearance to the valve which have 0.08mm (limit) of clearance help ?

I can buy the smallest shim 2.00mm this would give 0.08mm+0.05mm... .13mm of clearance!

regards,
laurent
1982 KZ810-R1 GPZ with hindle 4-into-1 pipe

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Re: Engine break-in....stalling at stop...overheating?

01 Jul 2011 21:03 - 01 Jul 2011 21:14
#460545
Here's more info ... spark plug pic (4 spark plugs identical)...



Light grey on insulator looks OK but cannot achieve light brown on insulator...

Fuel type 91 AKI (94 RON) a.k.a premium fuel

Checked coil (primary) resistance both around 2.6 ohms...

I will recheck valve clearance and update this post...
1982 KZ810-R1 GPZ with hindle 4-into-1 pipe

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Last edit: 01 Jul 2011 21:14 by ELCouz.

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Re: Engine break-in....stalling at stop...overheating?

01 Jul 2011 22:49 - 01 Jul 2011 23:30
#460570
Look at this is that valve float damage or what? Camshaft lobe at the opposite must not touch the valve bucket right (should have clearance!!!!) check the wear !!! WTF ????








Valve clearance exhaust recheck... #1 (0.13mm) #2 (0.12mm) #3 (0.13mm) #4 (0.10mm)

Picture show the exhaust valve #4 with 0.10mm clearance other one is intake with 0.15mm clearance


EDIT: full valve recheck

Exhaust valves:
#1 0.13mm
#2 0.12mm
#3 0.13mm
#4 0.10mm

Intake valves:
#5 0.17mm
#6 0.17mm
#7 0.16mm
#8 0.14mm

I will change the 2.05mm shim for the exhaust #4 to 2.00mm so i will be at 0.15mm clearance and be really DONE with valve clearance for a long time!

I will be changing my spark plug wires they are still original...hope this would help!


LAST EDIT: I always have a bubble of air in my fuel line does it mean anything (fuel starving when hot ? vapor lock ... i don't know!)

Also another clue....sometimes i hear hissing around gas cap...could vent be blocked or its just the vent doing its thing?
1982 KZ810-R1 GPZ with hindle 4-into-1 pipe

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Last edit: 01 Jul 2011 23:30 by ELCouz.

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Re: Engine break-in....stalling at stop...overheating?

02 Jul 2011 00:32 - 02 Jul 2011 00:38
#460583
(previous thread too long :P)
Other informations:

did a compression test:

# 148 psi , #2 136 psi , #3 135 psi and #4 135 psi (remember freshly ringed...only 10 miles on new set of pistons and rings)

Does fuel level have any effect on stalling when engine is hot?

I've noticed that if i fill my gas line with gas and the carb bowl are already full...after few minutes gas in the line disappear... this normal or gas leak into engine ?

Maybe it's my petcock with the automatic vacuum cut off (air leak when hot?) that is keeping the engine running rough then stall??

I will try to plug the carb #2 and run on prime on the petcock...

Seriously out of ideas...

I've ran through many checks...

Time to sleep!

best regards,
laurent
1982 KZ810-R1 GPZ with hindle 4-into-1 pipe
Last edit: 02 Jul 2011 00:38 by ELCouz.

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Re: Engine break-in....stalling at stop...overheating?

02 Jul 2011 08:53
#460607
ELCouz wrote: Dear kzrider members,
My recently built gpz 750 (now 810cc bored, wiseco kit) is stalling at stop...but wait

Yesterday did my carb sync everything was great ... good stable idle at 1100 rpm mixture was a bit rich on the pilots (colortune showed yellow flame on all cyl.) so i've turn in a little bit the 4 pilot screws and it was good.


Today is my first ride with the new pistons and valve job that has been done to the head...
Few minutes (15-20mins) of riding where perfect good idle at stop... then gone to the highway did a series of WOT at 5 min interval. Throttle response was perfect... no flat spot! Then when i exit the highway and start to run in city.

Few red lights after that, engine died when came to a stop! (first gear fully pulled clutch) Started again in panic then had to play with the throttle to prevent it from dying!

Also when i played with the idle adjustment I've noticed the engine looked abnormally hot! i burned myself on the clutch cover !

Is the bigger bore which can cause overheating ? Is the bike really overheating ... how do we know ??

best regards,
laurent

5 minutes of continuous full throttle operation on a fresh motor isn't the best method of breaking it in. You might have started to seize the cylinders.

The clearance on #4 exhaust isn't the cause of it stalling. However, the valves should have been tipped when the valve job was done so you wouldn't be nearly out of shim adjustment range.

Web cams might have some shims down to 180 if you need them. The problem with shims that thin is they fracture sometimes when the bike get's the living crap beat out of it.
Larry C.
cavanaughracing.com

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Re: Engine break-in....stalling at stop...overheating?

02 Jul 2011 10:13
#460618
Head has been milled, this retard timing normally but lacking proper tools (to check cam timing) and money :(

Damn store are closed today (canada's day) :( so no IR temp sensor !

For the colortune...my neighbors are going hardcore with the revving lately so I've only checked with colortune idle to 3000 rpm max! (relying on sparks plugs reading for WOT mixture...dark(dry not wet) around plugs and grayish on the electrode insulator...all of them are identical)

Also i cannot run on WOT on the highway while checking colortune that would be DEADLY crazy ! :woohoo:

No access to dyno too :(

thanks for the colortune chart but it's too small to read (picture) i will check on the net!

By timing, I meant spark timing. With a timing light/or static if you must, retard your ignition timing 2 degrees and try that.

Thats too bad about the IR Sensor...

The colortune chart is really helpful and you can download a good copy from Morgans Carbtune website: www.carbtune.co.uk/index.html

Sory my chart gets fuzzed up when I post it here, but it is otherwise OK for reading on my pc.

Good luck.

B)
Motorcycle Shop Owner/Operator

79 Kawie Z1000 LTD
81 Kawie Z1000 CSR
83 Honda VT750C A
85 Kawie GPZ900 A2
86 Zukie GS1150 EG
93 Yamie XV1100 E
Lucky to have rolled many old bikes through my doors ;)

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Re: Engine break-in....stalling at stop...overheating?

02 Jul 2011 10:16
#460619
ELCouz wrote: Here's more info ... spark plug pic (4 spark plugs identical)...



Light grey on insulator looks OK but cannot achieve light brown on insulator...

Fuel type 91 AKI (94 RON) a.k.a premium fuel

Checked coil (primary) resistance both around 2.6 ohms...

I will recheck valve clearance and update this post...

Your plug looks good. Full ring of soot on the base thread. Proper heat range on the strap, and you check jetting down inside the plug where the porcelin meets the metal - should be a whisp of light soot around the base of porcelin.

You can be over rich with a really good ignition system, and teh plugs will still always be hot ewnough at the tip to clean themeselves white like that.

B)
Motorcycle Shop Owner/Operator

79 Kawie Z1000 LTD
81 Kawie Z1000 CSR
83 Honda VT750C A
85 Kawie GPZ900 A2
86 Zukie GS1150 EG
93 Yamie XV1100 E
Lucky to have rolled many old bikes through my doors ;)

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