125-200cc 165 goodness

After playing with the 165 for a while and not getting it dialled in perfect I thought I'd try a new 144 kit again on my Wr125
I put 12 hours on the 144 kit and started thinking hmm better try that 165 that's sitting there again - with a new ring .

Put a new ring on it , a little extra base gasket ( .8 + .3mm) thickness and after an hour or so of riding the 165 was feeling great . It had never run so well ..
I was able to ride higher gears through tight corners and hills and was much smoother in power delivery . Not only that I think the extra base gasket gave it some more over- rev than previously
It was ripping and I was loving the top end as well.

We came to the same big steep grassy hill I did 3 weeks earlier that I had to man handle the bike up for the last twenty metres - and the bike overheated .
I went up first - I caned it up there and it pulled so strong all the way up - no sweat

Big thanks again to Walt for the mighty 165 kit ...

Video doesn't really show best bits but its not bad


View: https://www.youtube.com/watch?v=Meqn6l9KZAw

way to make the double log climb look to easy for the guy lol. Like your bike tho, looks like a real ripper.
I get the impression that its not worth wasting time and money on the 144 and just got right to the 165.

Yep Walts 165 kit is a cracking bit of kit and love mine to bits, Sadly mine has sat for months unriden along with all my other toys due to popping a disc or two out of my back but things are just about sorted now and should be able to get out again in the very near future for a gentle bimble

That was a lady who was behind me . She is tough though. The logs were easy but I stopped to think about it .
I think the bike surprised the 450 and 300 riders - ( guy on the 300 beta wouldn't move over all day ) so easy to ride in the tight trails , lugs so well and love the feel of the power band .
Yes Id go straight to the 165.

Yep that was a great video! We have lots of logs and rocks here and that's where the 165 keeps up with bikes twice its size....eagerly waiting for my lectron carb.....have the 200 pipe already and it's really great on the 165.

I like the stock pipe for great down low urge but also good top end - not so much mid.

Hi Rockdancer,

I noticed your setup includes an additional base gasket, I must admit I have really struggled with trying to get rid of the slight pinging and tried different jetting, and have come to the conclusion that only really cold days (12 degrees) work well for mine. Its more than likely the shit fuel we get here compared to the USA and I run fresh 98 plus an octane booster.

When I built my 165 up last winter, I used a stock base gasket and have run it like that with no issue. It runs spot on with my Lectron and 200 pipe. Only issue I have is when it is colder than ~30ish degree F, it takes about 10 min to fully warm up the bike as I have removed the thermostat and am running X2 coolant. Other than that, my 165 has been awesome.

Down under XC - I have been using the higher compression head - flatter chamber . When I ran it a couple of years ago on my previous bike it was detonating and still had some detonation with higher chamber design . Ive run it recently and it was OK with just a .8mm gasket but compression was low due to rings.
For some reason I had a massive ring end gap .
I always run 98 octane - will use Motul 800 from now on - I did use cheaper oils at one stage.

With new ring I thought Id throw on the extra gasket and it hasn't hurt it at all .
Its not hard to throw on an extra gasket and a new ring may help too.
New ring has brought compression up 20psi.