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montesa 4RT killing plug's???????

Posted: Mon Sep 06, 2010 7:44 pm
by antpoo69
i've been riding my 4RT for about a year and a half now. all of a sudden it has started to go through plugs like they are going out of style..... the standard plug is a CR6EH-9. i have run the standard plug and the CR7EH-9 and it has been killing them as well. just wondering if anyone has any idea why it has started doing this.

i don't really know too much tecnical stuff about these motors so hoping it's something that's easy to sort out.

Re: montesa 4RT killing plug's???????

Posted: Mon Sep 06, 2010 8:32 pm
by anthonyc
A CR7EH-9 is a colder plug so it will foul if you are fouling CR6EH-9!!!!

Re: montesa 4RT killing plug's???????

Posted: Mon Sep 06, 2010 8:37 pm
by antpoo69
so does that mean i should be trying a CR5EH-9 or should i try to work out why the problem has started all of a sudden? would the hotter plug solve my problems?

Re: montesa 4RT killing plug's???????

Posted: Tue Sep 07, 2010 12:28 pm
by Stork955
Gday, what do you mean by eating plugs? Are they getting fouled? (Black deposits on the tip)? If so, there are a few possibles causes. In no order - Air filter blocked, exhaust damaged or blocked (unusual for a 4 stroke) Too rich fuel for some reason -failed coolant temp sensor etc, faulty injector dribbling, oil consumption (rings/piston etc). This will do to get started with.

Cheers,


Stork

Re: montesa 4RT killing plug's???????

Posted: Wed Sep 08, 2010 8:45 pm
by bgradesherco
I've been running a CR5 in mine for a few months now with no dramas, give that a try Andrew.

Re: montesa 4RT killing plug's???????

Posted: Wed Sep 08, 2010 9:16 pm
by antpoo69
no worries... i'll give that a try... hopefully that fixes it. an easy fix like that sounds a lot better than all the other idea's stork955 has :-s thanks stork955 btw. if they plug doesn't fix it i'll have to work my way through your list of suggestions.

cheers :D

Re: montesa 4RT killing plug's???????

Posted: Mon Sep 13, 2010 9:58 pm
by sjj220
This was a simple solution to my plug problem, it may be of help.
Had similar problem a while back with my 07 4RT, at times it would foul a plug after one riding session. On some advice from another rider, I found that I had been over oiling the air filter and this caused the standard plugs to foul.
Now I only use a minimum of oil and clean the filter regularly (having a spare air filter makes life easier). If in doubt ring or email Montesa - Tarp Hassinen.