Author Topic: re-jetting needed?  (Read 1748 times)

Offline El__burro

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Re: re-jetting needed?
« Reply #60 on: August 02, 2017, 12:11:56 AM »
Still running like sh*t.
when I rev it sounds great. The problem is the second part off the throttle, it feels like it is electrical. 2 of 4 plugs are quite carbon fooled. Needle is back on the last position so it lets in more fuel. What are the best spark plug I can fit with the resistor caps?
Thanks
el__burro
« Last Edit: August 02, 2017, 12:13:34 AM by El__burro »

Offline Johnwebley

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Re: re-jetting needed?
« Reply #61 on: August 02, 2017, 11:13:41 AM »
Still running like sh*t.
when I rev it sounds great. The problem is the second part off the throttle, it feels like it is electrical. 2 of 4 plugs are quite carbon fooled. Needle is back on the last position so it lets in more fuel. What are the best spark plug I can fit with the resistor caps?
Thanks
el__burro

  which 2 plugs are fouled?  are they a linked pair?  IE;  1-4 or 2-3 ,

 both those pairs use common coils,points etc.if the other plugs are cleaner,and on the same carb settings,you could have ignition
issues ,

 secondly ,if the needle has its clip at he lower groove,it lets in more petrol,so will run richer ,from maybe 1/3 to 2/3 throttle ,
but all 4 carbs should be set the same,and all 4 plugs should be about the same colour ,


 
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Offline Greebo

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Re: re-jetting needed?
« Reply #62 on: August 02, 2017, 04:46:06 PM »
Still running like sh*t.
when I rev it sounds great. The problem is the second part off the throttle, it feels like it is electrical. 2 of 4 plugs are quite carbon fooled. Needle is back on the last position so it lets in more fuel. What are the best spark plug I can fit with the resistor caps?
Thanks
el__burro

You have tried many suggestions now so I think its time to get it booked in for a Dyno  before it drives you potty.

I cant see it being the plugs or resistors unless they are old & shot. plugs I use are NGK DR8ES-L... Resistor caps Part Number 30700-GAR-000 30700-MW3-000
It takes a whole tankful of fuel before I can think straight !

My Stable:-
Honda CB750TT
Triumph Thruxton 1200 R
Ducati Italia Scrambler

Offline El__burro

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Re: re-jetting needed?
« Reply #63 on: August 02, 2017, 04:48:37 PM »
What's the cost for a dynodyno test and where in london.

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Offline Greebo

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Re: re-jetting needed?
« Reply #64 on: August 02, 2017, 06:46:46 PM »
What's the cost for a dynodyno test and where in london.

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Sorry Mate no idea "of where in London" I'm in Yorkshire.
The cost depends on what needs doing but just a Dyno Run to find the issues is about £45 ish + parts + extra time etc.
do a search on google for your area
It takes a whole tankful of fuel before I can think straight !

My Stable:-
Honda CB750TT
Triumph Thruxton 1200 R
Ducati Italia Scrambler

Offline El__burro

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Re: re-jetting needed?
« Reply #65 on: August 03, 2017, 05:20:29 PM »
UPDATE
Plug 4 reads ok while the other 3 are fouled with carbon. all carbs needles are set up the same way and synced. After a 10 minutes ride i have notice that when i play with the fuel tap (on/res) it goes slightly better. It struggles at low rpm but when it reaches the second part of the throttle it pulls much more. Not sure if it is my imagination or there is a logic behind this. I have fitted the plugs DR8ES L and it goes "slightly" better.
Thanks
el__burro

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Offline El__burro

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Re: re-jetting needed?
« Reply #66 on: August 07, 2017, 06:31:16 PM »
Again,i have synced the carbs with the same air mix screw turns, (1and 1/2) carbs sync almost perfect. Still plug 1,2 and 3 are quite black with carbon deposit, number 4 i think looks ok.
DO I set the other 3 carbs air mix  screw to a different setting?
Thanks
el__burro

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Offline K2-K6

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Re: re-jetting needed?
« Reply #67 on: August 07, 2017, 08:38:13 PM »
It looks to me like you've got both resisted plugs and caps in use there at the same time ( correct me if wrong).Ordinarily it would be one or the other.

These engines are just not that fickle to get running well so it does seem that something odd is present to prevent a logical path through what's in front of you.

In answer to the idle air screws setting,  Honda setup instructions do allow for differences between each carb. They go through a routine of getting the lower speed  mixture the same for each one although they shouldn't in reality end up with any hugely odd set points as that would suggest some impairment of that particular circuit.

Offline El__burro

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Re: re-jetting needed?
« Reply #68 on: August 08, 2017, 12:12:11 AM »
k2-k6 you are correct, i am heading to Halfords tomorrow to see if i can find either a set of plug caps or a set of plugs with no R.
Thanks
 el__burro

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Offline Johnwebley

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Re: re-jetting needed?
« Reply #69 on: August 08, 2017, 10:03:32 AM »
k2-k6 you are correct, i am heading to Halfords tomorrow to see if i can find either a set of plug caps or a set of plugs with no R.
Thanks
 el__burro

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 can I suggest you try fleabay and/or amazon,both should be way cheaper than Halfords,
also more likely to be the correct items
lifelong motorcycle rider,and fan

Offline El__burro

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Re: re-jetting needed?
« Reply #70 on: August 11, 2017, 09:21:42 PM »
After swapping the spark plugs for NGK D8EA I've seen a tiny improvement. Still Plug 4 is perfect  (almost too lean) while the other 3 still a bit carbon fouled (less than with previous plugs) but at least the same colour.
Needle clip is at the bottom but bike still struggles in the mid part of throttle.
In the meantime i have re adjusted the timing.
Thanks
el__burro
« Last Edit: August 11, 2017, 09:25:39 PM by El__burro »

Offline Johnwebley

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Re: re-jetting needed?
« Reply #71 on: August 11, 2017, 10:43:21 PM »
After swapping the spark plugs for NGK D8EA I've seen a tiny improvement. Still Plug 4 is perfect  (almost too lean) while the other 3 still a bit carbon fouled (less than with previous plugs) but at least the same colour.
Needle clip is at the bottom but bike still struggles in the mid part of throttle.
In the meantime i have re adjusted the timing.
Thanks
el__burro

  the needle clip at the bottom?   is that the lowest groove?  that would give a rich mid-range,,try fitting it either in the middle groove,or
second from the top ,

  that should clean up the middle range
lifelong motorcycle rider,and fan

Offline El__burro

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Re: re-jetting needed?
« Reply #72 on: August 11, 2017, 10:47:41 PM »
After swapping the spark plugs for NGK D8EA I've seen a tiny improvement. Still Plug 4 is perfect  (almost too lean) while the other 3 still a bit carbon fouled (less than with previous plugs) but at least the same colour.
Needle clip is at the bottom but bike still struggles in the mid part of throttle.
In the meantime i have re adjusted the timing.
Thanks
el__burro

  the needle clip at the bottom?   is that the lowest groove?  that would give a rich mid-range,,try fitting it either in the middle groove,or
second from the top ,

  that should clean up the middle range
Will do tomorrow.
Thanks a lot
el__burro

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Offline sprinta

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Re: re-jetting needed?
« Reply #73 on: August 12, 2017, 08:26:45 AM »
Are your air screws the solid type or the ones with holes in?

Offline Jamesh_sussex

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Re: re-jetting needed?
« Reply #74 on: August 12, 2017, 04:25:07 PM »
My advice would be fit a standard airbox, go back to stock 110 main jets, setup and re-sync the carbs and get the bike running properly on a baseline intake setup. Then if you really need to go back to pods at least you know you have a solid baseline. You're playing with too many unknown variables and a lack of experience to converge on a solution with your current approach. Just my opinion...
Loads of SOHC4's....