1100ET HYDROLIC LOCK

[Novski]

HI there guys

I have been stalking this site for the last couple of years whilst restoring  what was a very sad 1100ET, and now I need some help and advice.

Yesterday I started the engine for the first time in a long while after rebuilding the top end. I was about to balance the carbs and after warming the engine up I put the vacuum gauges on but left the tap open on the auxiliary tank then went to start the engine, it turned over once... did not fire but then there was a very loud mechanical bang and the engine stopped turning over. I thought about it, took out the spark plugs and turned the engine over then fuel came out. Please can you tell me why it did this and have I damaged the engine conrods ? And is there a way to find out if I have done damage without stripping the engine ? I know you like  pictures, here she is when I got her and where I am up to.

[Blubber]

Don't know if there is a easy check.

A mate had the same and twisted the crank of his 1100Et.

 

I think checking all 4 top position of the pistons is needed plus checking the valves.  Might be possible via soark plug hole and a small bendy camera, like a endoscoop.

[Sheep]

How does it sound when it turns over?....if it turns/sounds ok could you do a compression check?

[kiwi]

sticking float valve has allowed fuel to go past pistons and enter cranckcases, remove sump plug change oil and try starting if it's damaged you'll know then, or strip it and check everything  choice is yours  ?, engines are out there but good luck finding a cheap 1, you might get lucky or you could be buying a rebuild job.

 

i do have 4 spare engines in various states of tune, as tend to buy them when they come up as now getting scarce.

 

Edited September 24, 2017 by kiwi

[strima]

^^This^^

I would try cranking it over by hand to give me an idea if anything is catching or jammed, then strip as far as necessary to see what the damage is.

[Novski]

Thanks for all your replies, engine sounds good when turning over and fires up straight away. Heard a lot of nightmare stories about hydraulic lock and spent so much time, money and love I'm nervous I may have done some damage. Will do the easiest and cheapest first (compression check) and I will let you know the results as soon as I can borrow a compression gauge .

[Swiss Toni]

Same thing had happened  on a certain makers 6 cylinder I'd bought. Fuel tap had been left in 'on' position, bike on sidestand. Fuel leaked past tap, and #1 cylinder filled up with fuel. PO turned motor over. BANG! 45deg bend in #1 rod. Big money re-build. I'd check the heights of all piston crowns, and compare. I'd also be wary of breaking the spigot off the bottom of the liners if you do have a bent rod. 

Edited September 25, 2017 by Swiss Toni

[johnr]

On 9/25/2017 at 4:28 PM, Swiss Toni said:

Same thing had happened  on a certain makers 6 cylinder I'd bought. Fuel tap had been left in 'on' position, bike on sidestand. Fuel leaked past tap, and #1 cylinder filled up with fuel. PO turned motor over. BANG! 45deg bend in #1 rod. Big money re-build. I'd check the heights of all piston crowns, and compare. I'd also be wary of breaking the spigot off the bottom of the liners if you do have a bent rod. 

very common cbx problem that. i know of two people its happened to. turns into a very very expensive rebuild!

[johnr]

tbh if your crank was twisted by this hydraulic lock, then it would vibrate like buggery because it will put the timing out  on one or more pots. if you can get hold of a degree wheel and a dti you can accurately check the tdc position of each cylinder just to set your mind at rest. but you could have been lucky.

[johnr]

the fact that it hadnt yet fired will have worked in your favour as the crank was only spinning at the speed dictated by the starter and not running much faster following ignition.

 

[Swiss Toni]

3 hours ago, johnr said:

very common cbx problem that. i know of two people its happened to. turns into a very very expensive rebuild!

It was! I took the bottom end to a 'specialist'. Never trusted it after I heard about some of his 'practices'. Got rid of it...wish I hadn't!

[johnr]

aye, my mate never left his parked on the sidestand again after his experience. in spite of the name of thee manufacturer, theyre a stunning piece of engineering tchnology from the age of oldskool, but fuck me theyre dear to fix when something goes wrong.

 

[Swiss Toni]

Yup! Everything comes in 6, 12, 24's and 48s! Vacuum tap cures it. Anyway, back on topic. He may have been lucky  in the fact it still turns over. But there again, so did mine! I'd guess the majority of fluid has probably gone past tired rings, and out the exhaust port. DTI is a good way to confirm. 

[Novski]

Hi Guys, thanks for all your comments. I have done a pressure test this morning. Number 12 and 4 cylinders read 125 and number 3 reads 110. However I have put a camera down the spark plug holes and in number 3 cylinder there is oil. How should I proceed? I am thinking of doing a top end strip down. Thanks again. 

[Swiss Toni]

Whip the head off for a look see. 

[BigT]

If it fires right up and sounds good, I wouldn't worry too much

Easy check - 4 soda straws, pull spark plugs and insert straws. Turn motor with a wrench to the TDC 1-4 mark. Mark straws 1-4 with a felt pen. Rotate motor back and forth a bit to confirm TDC. Repeat with 2-3

[pigford]

Amy news on it lad?

[Novski]

Hi guys, taken head off  and taken pistons to TDC all looks good. I am crossing fingers that I might have got away with it. Going to investigate a bit more as to why cylinder 3 is slightly low on pressure. any ideas?? thanks again.

[teltwosheds]

No idea what you've done engine wise but check the rings for aligned gaps. Or it could just be your rings and valves need bedding in