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lean plug

Posted:
Thu Aug 13, 2015 4:24 pm
by skinnerwill
Re: lean plug

Posted:
Thu Aug 13, 2015 4:36 pm
by skinnerwill
been trying to jet a 26 phbh, pic of plug was taken at 1/4 throttle run.
pilot 45
x7 needle
main 110
originally pilot was 55 but struggled with tickover, revs would pick up only when it was down to a quarter of a turn and would run even with screw right in, dropped to 50 and was pretty much same, dropped again to 45 and managed to get tickover on 1 turn out.
if theres any stuttering on bike its very slight at about 1/8 throttle but pulls through it very easy (on road)so only notice it when tootling behind slow traffic. otherwise pulls strong but worried by plug.
its a 175 ,tried it with a clubman and expansion pipe , same plug colour
I also tried a 30mm phbh which was set up richer, 55 pilot x2 needle, 115 main, pulled a lot stronger and seemed to rev better at top end but same probs with trying to set tickover up and plug basically same.
do I start pulling apart looking for air leak
Re: lean plug

Posted:
Fri Aug 14, 2015 10:16 am
by hullygully
you haven't said what atomisor you've got or fuel jet (float pluger jet) or slide?

Re: lean plug

Posted:
Fri Aug 14, 2015 12:07 pm
by MickYork
also whats your timing set at ? Could be an electrical problem ?
Re: lean plug

Posted:
Fri Aug 14, 2015 1:18 pm
by skinnerwill
40 slide
AV266 atomiser
200 fuel jet (if you mean one on needle valve / float bowl shut off)
70 choke
18 degrees static timing and also checked with strobe
what I didn't mention above was I have also tried a 22mm jetex of mine and also one off my mates running bike and my plug always the same. mates bike is a 200 gp and his plug is chocolate brown
had putoline 2 stroke oil at first and now using rock oil
Re: lean plug

Posted:
Mon Aug 17, 2015 10:41 am
by hullygully
I've a 26mm delly on my Gori 200cc, Ancillotti, hollowed out airbox, needle X7 P1, 45 Slide, AV266 Atomisor, 45 Pilot, 105 m/jet, but Ive read somewhere that the fuel jet for a 25/26 delly, needs to be 250!!! like mine, yours @ 200 looks to be where your problem is on the 26mm
but if you have the same plug colour on all 3 carbs then I'd defo start having a looksy internally
Re: lean plug

Posted:
Tue Aug 18, 2015 3:10 pm
by skinnerwill
Re: lean plug

Posted:
Tue Aug 18, 2015 3:14 pm
by skinnerwill
[URL=http://s24.photobucket.com/user/li175sswill/media/WP_20150817_15_49_41_Pro_zps10xrep6r.jpg.html]

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Re: lean plug

Posted:
Tue Aug 18, 2015 3:15 pm
by skinnerwill
Re: lean plug

Posted:
Tue Aug 18, 2015 3:16 pm
by skinnerwill
Re: lean plug

Posted:
Tue Aug 18, 2015 3:19 pm
by skinnerwill
stripped top end, seems to be a fair bit of oil on piston skirt although bike doesn't seem to smoke when been ridden
any other tell tale signs ?
Re: lean plug

Posted:
Tue Aug 18, 2015 4:40 pm
by coaster
The oil deposits look healthy, there is some slight blow by below the rings so maybe compression is down a bit but air leak wise the base gasket looks a bit suspect around one of the stud holes

Re: lean plug

Posted:
Tue Aug 18, 2015 6:51 pm
by skinnerwill
I had a chat with lad at MB, he said pretty much same. told me to ride it quite hard for a while and then try doing some more plug chops as really couldn't tell from one that's in with it being new
Re: lean plug

Posted:
Thu Aug 20, 2015 4:52 pm
by skinnerwill
rebuilt top end, new gaskets and sealed with trubond
26mm phbh just wont run anywhere near unless you start weakening it, went from x13 to x7 top clip, 105 main and as for tickover had to drop to a 40 pilot . to get near tickover with 2 1/2 turns out but rides horrible on 1/8 to 1/4 throttle. if im reading it right it feels like 4stroking till you give it a bit more throttle, plug doesn't look too bad but daren't really weaken it anymore
now as for 30mm phbh its totally opposite, x2 needle 2nd from bottom clip, 115 main 50 pilot. mixture screw 1 1/4 turns out but rides sound at low revs, just doesn't rev out completely suggesting main needs dropping slightly but as for plug its the same as first pic, looks lean (did about 7 miles)
both av 266 atomisers
tail pipe dark and oilyish if you put finger down it
only other thing I can say about 26mm was , tried setting it up as per some threads say with main out to begin with, but it was hard to start and wouldn't go past 1/8 1/4 throttle at all so had to put main back in to set up
Re: lean plug

Posted:
Thu Aug 20, 2015 5:53 pm
by Warkton Tornado No.1
Did you ever try a float needle valve bigger than 200 as recommended earlier?
Re: lean plug

Posted:
Thu Aug 20, 2015 9:56 pm
by skinnerwill
no, forgot all about that if honest. ring round tomorrow and see if I can get one
Re: lean plug

Posted:
Fri Aug 21, 2015 8:15 am
by Captain Pugwash
It makes a big difference fitting a larger float needle, I ditch the 200 and usually fit a 300 but never less than 250.
Re: lean plug

Posted:
Fri Aug 21, 2015 5:54 pm
by skinnerwill
okay, got a 250 float valve jet, on 30mm it didn't really make any difference, get it to run nice and clean but plug still same
put 250 into 26mm and set it up richish, x2 needle, 50 pilot, 115 main. it just didn't want to start and when it did really struggled wouldn't rev at all. so started leaning it off, set up is now 105 main, 45 pilot, x13 needle on top clip. very very slight hesitation on about 1/8 to 1/4 throttle but pulls through easy and nice and clean. didn't really have time to do proper plug chop but did a couple of miles at around 1/4 throttle no more than half at any time. plug is now black and sooty

, so hopefully I can start dialling it in some more tomorrow, i'll drop to x7 needle and see how it goes.
as for 30mm just wondering now if that might need a 300 float valve jet as you mentioned earlier
Re: lean plug

Posted:
Sun Aug 23, 2015 11:03 am
by skinnerwill
okay did more plug chops, 1/4 throttle sootyish, 1/2 and 3/4 greyish, flat out (more or less )it does look as though its putting some tan colour on plug. so left with what looks lean on plug in midrange but runs fine, if I richen it by moving clip it starts bogging a little more from 1/4 throttle and you need to give it more revs to pull through it.
not sure where to go from here, shall I just ride it and see what happens
