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Strange one this

PostPosted: Sat May 25, 2019 8:31 am
by neil64
Hi

I am running a mugelo 186, with a club man , and a delorto phbh26 carb .pretty standard set up these days . Starts fine ,I've jetted as to certain dealers website , pilot 50, atomized av 264, needle x4 ,mid clip . Rides ok up to 3/4 throttle then a slight 4 stroke then has the effect of cutting out . I'm currently at 100 main jet , any suggestions ?. Thanks in advance .

Re: Strange one this

PostPosted: Sat May 25, 2019 8:38 am
by MickYork
Have you checked flow from tap ? Might be running a bit slow, worth checking.

Re: Strange one this

PostPosted: Sat May 25, 2019 11:18 am
by ULC Soulagent
Also suggest you check which float bowl needle jet you have in it ;)

Re: Strange one this

PostPosted: Sat May 25, 2019 1:23 pm
by neil64
Currently using metal float bowl with needle x4 - av264 atomiser.cheers

Re: Strange one this

PostPosted: Sat May 25, 2019 3:01 pm
by ULC Soulagent
neil64 wrote:Currently using metal float bowl with needle x4 - av264 atomiser.cheers

No, not the float bowl itself but the float needle jet

Re: Strange one this

PostPosted: Tue May 28, 2019 9:51 pm
by neil64
Ok , its got 2-25 on the side of it ,cheers

Re: Strange one this

PostPosted: Tue May 28, 2019 11:35 pm
by ULC Soulagent
neil64 wrote:Ok , its got 2-25 on the side of it ,cheers

Well that’s ample for a 186 kit

Re: Strange one this

PostPosted: Wed May 29, 2019 8:01 am
by coaster
If its consistently cutting out at 3/4 throttle then that would suggest that the main jet is the issue. 100 sounds too small to me, try going up several sizes until it gets boggy above 3/4 and then come back down in stages. That throttle position corresponds to the transition from the needle/atomizer to the main jet.
As already mentioned, fuel flow could be an issue, Have you firstly checked the flow rate from the tap? (you should be using a fast flow tap with a Mugello) If you undo the pipe from the carb and put a bowl under it think you need to flow about 1/2 litre in a minute (check Stickies book).

Re: Strange one this

PostPosted: Thu May 30, 2019 4:04 pm
by neil64
hi , inlight of this issue , and looking at the spec of this carb which should be correct . ive been offered a 28 pwk to try . so im carefully going to try it , have been pointed to a website for jetting spec but ive been advised it should be somewhere near , shall see.

cheers ,

Re: Strange one this

PostPosted: Thu May 30, 2019 7:30 pm
by Bogie
just had a muggy on the dyno today , same set up apart from a gori pipe . 40 slide , Av266 atomiser x7 needle 2nd clip down , 55 pilot and 115 main

Re: Strange one this

PostPosted: Fri May 31, 2019 12:07 pm
by Rich Oswald
Bogie wrote:just had a muggy on the dyno today , same set up apart from a gori pipe . 40 slide , Av266 atomiser x7 needle 2nd clip down , 55 pilot and 115 main


What CC Mugello? Pilot seems big imo.

Rich'

Re: Strange one this

PostPosted: Fri May 31, 2019 4:23 pm
by Donnie
neil64 wrote:hi , inlight of this issue , and looking at the spec of this carb which should be correct . ive been offered a 28 pwk to try . so im carefully going to try it , have been pointed to a website for jetting spec but ive been advised it should be somewhere near , shall see.

cheers ,


That is a mistake, you really should simply check the flow of the tap then put a 118 main jet in.

Now changing carbs you're going to be jetting completely again and facing a different problem.

Re: Strange one this

PostPosted: Fri May 31, 2019 6:26 pm
by MickYork
1st post after posting the question suggested checking flow rate, mentioned again by others.......

Re: Strange one this

PostPosted: Fri May 31, 2019 8:08 pm
by Bogie
Rich Oswald wrote:
Bogie wrote:just had a muggy on the dyno today , same set up apart from a gori pipe . 40 slide , Av266 atomiser x7 needle 2nd clip down , 55 pilot and 115 main


What CC Mugello? Pilot seems big imo.

Rich'

it was a 198 small block , and i always run a big pilot jet on everything . she runs and idles spot on ...

Re: Strange one this

PostPosted: Sun Jun 02, 2019 8:32 pm
by dscscotty
Try a different float bowl, a friend of mine has experienced issue with an alloy float bowl when changing from a plastic one, not sure of the reason but reckoned it was cured when reverting back to plastic one,

Re: Strange one this

PostPosted: Sun Jun 02, 2019 8:35 pm
by dscscotty
Just re- read this-x4 needle??

Re: Strange one this

PostPosted: Wed Jun 05, 2019 7:27 pm
by neil64
yes an x4 , as with cam lam guide.

Re: Strange one this

PostPosted: Wed Jun 05, 2019 7:53 pm
by dscscotty
I'd try another needle, possibly x7,

Re: Strange one this

PostPosted: Wed Jun 05, 2019 8:19 pm
by Toddy
dscscotty wrote:I'd try another needle, possibly x7,


+1

Re: Strange one this

PostPosted: Wed Jun 05, 2019 10:05 pm
by Rich Oswald
Toddy wrote:
dscscotty wrote:I'd try another needle, possibly x7,


+1


+2