phbh rich slide vs rich mid range

[olliewtf]

oh and thanks drunkmonkey for throwing experience into this, Im finding it very useful so please stick with it! haha Just dont mention the word dyno

[olliewtf]

Righto. dropped the x13 to top clip and it ran smooth as; 2nd clip was spluttery n horrible. So thats got to be spot on. I then fitted a 135 main jet, 4 stroked. swapped for 130, loves it. may try 132 but i think its about right.

One thing thats troubling me is the pilot. In order to get rid of the odd revs hanging above tickover thing I thought Id go richer to see if that helped. Fitted a 57 pilot, and even if i wind the mixture screw out a good 3 turns it still wont help the problem. If i blip the throttle, the revs do drop in good time, but they hang just above tickover for a good few seconds before dropping to tickover. Its bugging me alot. I think a 60 pilot must be overkill. Maybe the answer is a 35 slide; I may modify my 30 slide and give that a go. Thoughts? Slowly getting there I think!

[drunkmunkey6969]

Just to clarify something first... have you ever done a leak down test to check for airleaks?


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[olliewtf]

are knew that one would come up haha... NO. Im planning to get the bits together, and when i do I shall carry one out. For now Ive touched a bit of soapy water around manifolds with the engine running, and it checks out. All joints a dry. However a leak down would obviously be more thorough.

Im going to try a 60 pilot and if it sorts it then im more conscious of a leak, as thats quite big. That said, the rest of the jetting is pretty conservative. And i did have a similar ish problem before with a 40 slide, though top end has been hugely re-tuned.

[olliewtf]

Tried the 60 pilot and it ran okay. revs still hang occasionally, but im not convinced anymore that its due to it being lean. I may post a video and see what people think. I did check if the slide was sticking, but tbh the difference in rpm you probably wouldnt be able to see, if you factor in all the shaking.

Out of interest i changed it for a 55 pilot, and it ran again. this time though at 1/8 throttle / progression if i held it it would lean out as it went into the power.

Im thinking therefore I should modify my 30 slide to a 35 and try that. that said the 30 slide ran fine as it was, and ive ruled out overly lean mid range in the tests ive carried out. But as has been suggested a 30 slide is not commonly used as its too rich, and its use in my set up could indicate a leak. The reason im skeptical however is that I dont have any other air leak symptoms and in the rest of the range there is no jetting oddity. Tricky.

[drunkmunkey6969]

Next question....what's your method of defining the weak spot on 1/4 throttle progression? Are you going plug chops?


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