Athena 170cc questions

[Irongamer727]

Is it necessary to go for 3% oil mix? Thinking about just tuning the oil pump a bit
Heard about many people who still drives with the pump with this kit

[Jens Eskildsen]

I think the oil pump should be able to add sufficient oil, using a half-decent oil.
Many enduroriders on 300 2-strokes use way less than 3%

[Calum]

It's a good point though.

It is a bigger CC and the pump was only designed for a 125.

Pretty sure my brother ran with stock oil pump settings no problems.

[finnerz89]

A guy on the YOC had one in his TDR, ported and tuned. Did 30 odd thousand miles before the gearbox blew up!

[Calum]

@finnerz89 Jeez, is YOC still going?

I haven't logged on in ages. Used to be great back in the day.

30k miles isn't a lot, especially considering these boxes are straight cut.

[finnerz89]

@calum decent amount for the 170 kit though?
I don't know exactly what went wrong with the box, but it stopped selecting gears so probably bent selector forks

[Irongamer727]

@finnerz89 why would the 170 kit affect the gearbox ?

[Calum]

@irongamer727 More torque than what was initially designed.

The box is pretty over compensated on these bikes, I'd still say 30k is low.

I suspect the bearings failed, which in turn damaged the box. I'd expect that to happen. Again if the bottom end was rebuilt as per maintenance then that would have been avoided.

It's the first I've heard about gearbox going due to the Athena kit.

With that in mind, I shouldn't worry too much.

[Irongamer727]

Allright. Every part has arrived. Now. Once I installed the kit and put a big main jet and lowered the needle(more fuel). Should I start it and ride 500 km with the settings way off?( way to much fuel) Or should I lower the jetting until he rides okay? Thing is I don't won't to put any stress on him when the kit just has been installed. How would you do?

[declan]

@irongamer727 sorry I know you are asking important questions but did you just refer to your bike as a “him”

[declan]

@declan and personally no I’d adjust the oil pump to run more oil which is what me and @Calum currently already do

[Calum]

@irongamer727 You're going to want to ensure you jet it properly and ride it accordingly.

[declan]

@calum is he not planning on jetting it?oh I see just by banging a main jet in don’t necessarily mean it’s correct as all bikes are different and it’s a pretty precise task

[Calum]

@declan Main jet only affects 3/4 to wide open throttle, so no, he's not jetting it properly.

The jets need to be changed to accomodate the whole rev range.

[oldman]

@declan said in Athena 170cc questions:

@irongamer727 sorry I know you are asking important questions but did you just refer to your bike as a “him”

Haha haha! Careful, this day and age your bike should be "gender neutral", don't force sexuality on your bike, let it choose or you are going to be on Jeremy Kyle!

[Irongamer727]

Read my question again. I'm going to jet it. I know 90% of people use either a 270 or 280 main jet. My plan is to adjust the needle. (As rich as possible) and put a 290 jet in to begin with. But I presume 290 will be to big. It's just to be on the safe side. The tricky part is that I cannot just rev him and see if 290 is to big right? Not until the cylinder has done about 500 km. So either I drive the first 500km with a way to big jet and risk destroying the spark plug and stuff due to the co2 build up. Or I try reving him early to adjust him before the 500 km. That's the dilemma.

[Irongamer727]

@oldman the bike do have male characteristics

[Calum]

Yeah I read it.

Did Athena not provide the correct jettings with the Cylinder kit. That is my gribe.

How could they develop a kit and then not recommend some jettings for it lol.

If we're talking all honesty here.

Get her running sweet on idle, not in gear (you can rev the nuts off it and it won't damage anything provided there is oil) and just make sure it's all good.

Then run her in gently, then sort the jetting out on WOT using the described plug chop methd.

[Irongamer727]

Allright. I agree. Jets should be accompanied with the kit. Another question. After i fitted the kit. If "the bike" starts with no problems. Should I worry about the idle mixture? Or just keep going? Don't won't it to break down due to a lean idle mixture. Is that even possible?

[Calum]

@irongamer727 If the bike idles happily, and you pulling the throttle doesn't cause hesitance or bog, then the idle mixture is correct. I can't see the idle mixture increasing massively, but definitely should need to be notched up slightly.

For the running in period, you shouldn't actually need to up the main jet, as you should be hitting WOT. But I'd rather have it and not need it, than need it and not have it.