second time blown HG

3265 Views 14 Replies 7 Participants Last post by mpp12, Jan 10, 2017

mpp12

Discussion Starter · Jan 9, 2017

I changed my HG a year ago, this time, same circumstances, going WOT 6th gear, in a long staight road.

We where going terminal speed...

and my temp starts going up, stooped the bike and my reservoir is above F mark and I see bubbles....

bike has thinner HG, a degree, and nothing else.

any ideas why this happened again..

last time we checked the head, block, etc.

Im running 2 lean or something????

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realpsi

· #2 · Jan 9, 2017

Add fuel above 12.5 k and slowly ramp down timing to stock values at 14k. Running an engine at high rpm max load puts a lot of heat in the cylinder. Add fuel to cool it down. I have added fuel in the past to get through some knock due to timing, but at high rpm and high load I would just pull the timing. You are not there long enough during normal use to lose too much power.

My .02 worth

michael4012

· #3 · Jan 9, 2017

Are we presuming the temperature started to rise as the head gasket blew or are we assuming the the temperature rising is down to bad FAR & or ignition advance that caused the gasket to blow. But what has happened is the gasket has blown to water jacket (bubbles in expansion tank) second time im not sure what happened the first time to cause a gasket blow but was the head & block checked for level, is it a quality head gasket?

mpp12

Discussion Starter · #4 · Jan 9, 2017

Oem gaaket
Both things measured

Enviado desde mi iPhone utilizando Tapatalk

Carlos76

· #5 · Jan 9, 2017

Basics checks:
You torque wrench being true.
Bolt thread and washer lubrication with moly is important.

Thermostat.
Careful after coolant fill, it takes 3-4 cooldown cycles for all air to come out.

I'm building a test to measure delivery rate when fuel pump starts to drop pressure.

Reactions: 1

michael4012

· #6 · Jan 9, 2017

So presuming the head was pressure checked & there was absolute visible evidence that was the head gasket itself that has gone twice, was there any indication of burning on the pistons or spark plugs, the pistons normally burn at the front nearest the exhaust valves. Has the gasket gone in the same place twice. The picture attached is of a severe case of running lean its burned a chunk of piston away.

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TechnologistX

· #7 · Jan 10, 2017

I would check to see what the compression has risen to with the thinner gasket.

thundercoupe9

· #8 · Jan 10, 2017

I had similar result when I reused my factory head bolts. I replaced them with arp head bolts and haven't had anymore hg issues.

mpp12

Discussion Starter · #9 · Jan 10, 2017

Thundercoupe,

incredible, I had the same problems with my gixxer, and used (dont remember name studs and cero problems).

could you guide me where I can find those bolts....

mpp12

Discussion Starter · #10 · Jan 10, 2017

APE makes also I see....

mpp12

Discussion Starter · #11 · Jan 10, 2017

RC performance, had them in stock. studs and nuts. 185, shipped.

ninja_12r2000

· #12 · Jan 10, 2017

Well well.

First do a compression test.
Second if you don't see lost between 2 cylinders who are contiguous the head gasket probably not blown.

Now if you put the head out, there will be a visual sign on the gasket a dent or something who show antifreeze going on the cylinders.

I f there's any antifreeze mixed with the oil ????

In which case the water pump or the seal of it could be the guilty part.

The head gasket as fact could be reused, just have to clean to bare metal the gasket and put gasket kinch on each part of the gasket tight it and should be O.K....I always do that and no issue.

Check the head and the block for cracs dent or something to be really sure. Good idea to check the head and the block for straighteness look at the repair manual they explain all that.

The head gasket blown sometimes but it's very rare or the gasket have a dent or something between the layers of it.

The head bolts ..... well if it is not broken and tight evenly to specs it will do the job even used they already show that in the repair manual 42 lbs/po2 for new one and 45 lbs/po2 for new one or something near, check in the repair manual for the exact numbers.

But check the water pump got this problem on a gen 1 and yes water going to the oil, from this part. Change the water pump = problem over.

And yes if you change your stock head gasket for a thinner head gasket the motor will run hotter and you probably need to put a manual switch to activate the radiator fan to keep the motoe to normal temperature.

It's about it.

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mpp12

Discussion Starter · #13 · Jan 10, 2017

there is no water in oil...

Im waiting to see what the mechanic see, when takes all apart.

ninja_12r2000

· #14 · Jan 10, 2017 (Edited)

I was thinking you are doing the job yourself....
Just ask to the mechanic what he do, because if it's the second time he change the head gasket without doing something wrong well there's a crack probably in the head or the block.

Assuming your mechanick are good.

mpp12

Discussion Starter · #15 · Jan 10, 2017

Im not doing the hand labor....

I have a full time job, so I cannot spend lots of time working on the bike, I supervise the work.

we will take the head to be checked, to see if there is any crack.

the first time, we saw no apparent damage in the HG, we replaced it and runned for 6 months CERO problems, we are expecting the same here. but this time we are going to put the APE studs.

This same scenario happened to me long time ago with a K6 gixxer, thinner HG, (that bike cranked 240 on all cylinders in the test), then started to leak, CERO signs in the HG. then we replaced the HG, same shit, then we changed the studs to APE, CERO problems, lots of racing 305km/h top speed, and cero problems.

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