140cc and 150cc Yx engines.

[haveagoade]

Here are some tips in tuning up a 140cc or 150cc YX engine with IRK.

Follow out the PDI as per the instructions in the PDI sheet and here….. http://www.stompracing.co.uk/newsite/more/more/downloads_assets/pitbikePDI4.1.pdf


It is advised that the ignition timing be set fully retarded on first starting the bike. This is to prevent possible engine kick back on first starting the bike.

The Yx with IRK has no heavy flywheel and kicking produces comparably reduced forward engine momentum . The higer cubic capacity on 140’s and 150’s may catch unexperienced riders out with a kick back. If this is combined with an inexperienced kickstart then the engine can easily kick back, this tendency is reduced if the ignition is retarded.

The down side to this is glowing exhausts due to higher exhaust gas exit temperatures and sometimes poor running. This can be overcome by richening the idle mixture a fraction .

Also, Once the bike has been started and partly run in , it is advised that the ignition be advanced back a fraction towards the factory set central position together with fine tuning of the carb idle adjustments.

The richening of the idle mixture and fine adjustment of the timing will achieve the ideal tuneing of the YX engine.

A glowing exhaust is a sign of an over lean mixture and too retarded an ignition setting.

[Despise]

n1 there dave :)

[haveagoade]

Who's Dave......I ain't the "Home of Witty Banter":icon_lol:

[Despise]

:D

[Ste_1]

Quality post!!!

Nice one ade. :thumbs:

[thumpa383]

finally some sense on how to tune the yx. i been trying for ages to get the ideal set up. but always seems im taking one step forward and two steps back, however i went out on my yx140 yesterday and she was a flyer!!! it whoops my mates lifan 140 with irk!! mine sounds like a 2stroke compared to his!! will sort out the timing and see how she performs. also this stomp hates water! even though i taped up the cdi.

thanks ade

[haveagoade]

Try spraying the coil and lead with WD40 or use better Waxoyl to keep out moisture.

Also the paint on these frames is quite thick and sometimes the earths to the frame could do with a bit of the paint scrapped off. Then grease them or wax them so they don't rust.

Also The 150cc has a comparably huge carb and any moisture just gets sucked up into the foam and gobbled up like a huge vacuum cleaner.

[Despise]

finally some sense on how to tune the yx. i been trying for ages to get the ideal set up. but always seems im taking one step forward and two steps back, however i went out on my yx140 yesterday and she was a flyer!!! it whoops my mates lifan 140 with irk!! mine sounds like a 2stroke compared to his!! will sort out the timing and see how she performs. also this stomp hates water! even though i taped up the cdi.

thanks ade
its prolly the coil

[spitfire123]

Also, Once the bike has been started and partly run in , it is advised that the ignition be advanced back a fraction towards the factory set central position




ive dont about 1 hours running in so far so shall i put the coil pickup back to the central possition?also i cant get a decent mixture it splutters alot.amd we reset the timing again today, is that my problem because its still in the fully retared position?:confused:


thnx

[Ste_1]

ive dont about 1 hours running in so far so shall i put the coil pickup back to the central possition?also i cant get a decent mixture it splutters alot.amd we reset the timing again today, is that my problem because its still in the fully retared position?:confused:


thnx


Yea put it back to the middle, sorted my 150's mixture probs out pretty much straight away.

[spitfire123]

Yea put it back to the middle, sorted my 150's mixture probs out pretty much straight away.




oh righ cool:thumbs:


also how far away does he pickup have to be away from the magnet on the spinning wheel?

[Ste_1]

oh righ cool:thumbs:


also how far away does he pickup have to be away from the magnet on the spinning wheel?

I wouldn't worry about that mate, it should be fine as is.

[Charlie_G]

Can anybody get a picture of what the pickup has to be like after 1hrs running in please?

[spitfire123]

[quote=Charlie_G;75887]Can anybody get a picture of what the pickup has to be like after 1hrs running in please?[/quot



central aparently?:thumbs:

[Ste_1]

Ill get one up when i finish work.

[spitfire123]

right...................


ive put it in the central possition and put it 0.5mm above the magnet with a feeler gauge like the other pickup next to it....


and i quicky leared it it 3/4 of a turn and went 1/2 to 3/4 throttle in my garden up the path and it wheelied!!!!!!!


at last:o

now i have about another hour of running in to do:(


thank you guys:thumbs: :thumbs: :thumbs: :thumbs: :thumbs:

[haveagoade]

We been saying to do this for the last week or so...glad to hear you sorted:thumbs:

Enjoy!

[haveagoade]

Whats really need is to take all the hit and miss out and put a strobe on it and check the timing properly to the correct 10 to 15 degrees.

[spitfire123]

Whats really need is to take all the hit and miss out and put a strobe on it and check the timing properly to the correct 10 to 15 degrees.


wts the cheapest i could get won 4?

thnx

[Ste_1]

They cost pennies tbh. I think you can get em for about £30. But you need a 12v batt for most, or a car close youre bike lol.

Unless you get a digital one, but there pretty pricey.

I dont know how to use one but ive seen a few people using them on cars and its something like setting the dial to 0 at a certain RPM then checking the strobe flashes in time. But i know there simple to use.

[haveagoade]

You use a flashing strobe one that goes inline with the spark plug, it flashes same time as spark, point this at the mark on cam and you done and dusted.:thumbs: