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High compresion ???

Posted: Wed Mar 11, 2020 9:58 am
by retrovan
Hi Guys,

This is totally off the wall, But have never got this issue in all my years.

Have a 6Hp generator, that has run for 5 years or so, no problem.

Now all of a sudden, it has developed excessive high compression , so much so that you break the pull string trying to start it.

When she gets to TDC its as if she has a fuel lock, ie, as if the chamber is full of fuel.

Full lock, but if you keep tension on the rope, she slowly goes through compression and turns freely again.

When you remove the spark plug she runs freely, and nothing is ejected out the plug hole.

Now you may say she has per-ignition, but this happens even when ignition is switched off with no spark.

Even removing the plug lead, she still does this.

Now I have removed the rope pull starter and when fitting a drill and socket she spins and starts no problem.

Yes a bit of a jerk on the arms but she runs.

Now you may think that after running for 10 min or so she would be easy to start as its got the "Fuel Lock" out of its chamber, but no

She has this same problem the sec you stop her again.

Any ideas ........ :huh: :wtf:

Herman

Re: High compresion ???

Posted: Wed Mar 11, 2020 10:52 am
by fig
Excessive carbon build-up in cylinder?

Re: High compresion ???

Posted: Wed Mar 11, 2020 10:55 am
by retrovan
fig wrote: Wed Mar 11, 2020 10:52 am Excessive carbon build-up in cylinder?
That is an option, thanks Fig, will strip and look after load shedding.....

Herman

Re: High compresion ???

Posted: Wed Mar 11, 2020 12:17 pm
by Tony Z
sounds like your pull start mechanism is giving you trouble

Re: High compresion ???

Posted: Wed Mar 11, 2020 12:27 pm
by retrovan
Tony Z wrote: Wed Mar 11, 2020 12:17 pm sounds like your pull start mechanism is giving you trouble
No Tony, the motor turns over effortless when plug is out, but with plug in, the motor comes to dead stop on compression stroke and due to you pulling hard, the rope breaks.

But yes its like a dead stop. not sure if you ever had a liquid lock in a engine, but that is what it feels like.

If turned by drill it jerks in you hand badly but gets past TDC and starts and runs perfect.

No noise or any problem of sorts.

Herman

Re: High compresion ???

Posted: Wed Mar 11, 2020 5:32 pm
by Haans
Brake fluid whilst running ?? Heard that from you ??

Re: High compresion ???

Posted: Wed Mar 11, 2020 5:43 pm
by Tony Z
did you recently change the plug? Maybe the one you put in is too long?

Re: High compresion ???

Posted: Wed Mar 11, 2020 8:02 pm
by retrovan
Nothing changed, all is still as it was over the years, when she runs she runs good, but to get her over that bump, with the pull rope is impossible where as in the past you lazily extended your arm and she starts.

@ Haans yes that is one of my remedy's for carbon, and yes I will be trying it one evening when there is nobody around in this here stuck up complex......... :roll:

Why I hear some of you ask, well she smokes like a steam train when you burn brake fluid.... :shock:

Herman

Re: High compresion ???

Posted: Thu Mar 12, 2020 9:38 am
by Haans
Make the missus goes a visting !,😆🤣😂
Haans

Re: High compresion ???

Posted: Thu Mar 12, 2020 1:04 pm
by Terry Phillips
Herman you get 2 types of short plugs there is an extra short plug that is used on small plant engines.
Just try screw your one out half a turn at a time until it turns over. :idea: