NC35 carburation query

LUCAS · Post by **LUCAS** » Thu Sep 02, 2010 11:41 pm

I got my NC35 a couple of weeks ago now and it was totally standard. It has a receipt for a full service only 200 miles back. 2 valve clearances needed altering but they are all now ok. Had new plugs also.

I put a single Tyga carbon silencer on the very next day

It has been on for 2 weeks. My query is that it doesn't need any choke at all no matter what condition. This morning it was could enough to see my breath but again it didn't need any choke to start. It idles at low revs happily. However, this morning going through the village at neighbour friendly revs i pulled onto the main road and it spluttered really badly and ran onto 1 or 2 cylinders. I paddled my way across the road and pulled to the side. I was able to bring the revs slowly up and clear it fine. 30 seconds later i was on my way.

Im guessing its running lean because of not needing any choke and maybe was close to fouling the plugs up??? I did allow a good few minutes to allow the motor to warm up.

When downshifting it does pop and bang (music to my ears) from 6.5k to 5k revs.

Whats the recommendation for jetting changes etc with a change to that silencer?

Thanks

Harvd · Post by **Harvd** » Thu Sep 02, 2010 11:59 pm

Yup theres a lot of pop and crackle in these cans

i ended up going for 115s after trying some 112s i also fitted some 0.5mm shims under the needles. This flattened out the midrange really well.

I should get a scanner and put my dyno run on here. Standard everything bar exhaust and carb jetted to suit. such a linear curve and 59 hp

code2006 · Post by **code2006** » Fri Sep 03, 2010 12:00 am

LUCAS wrote:I got my NC35 a couple of weeks ago now and it was totally standard. It has a receipt for a full service only 200 miles back. 2 valve clearances needed altering but they are all now ok. Had new plugs also.

I put a single Tyga carbon silencer on the very next day It has been on for 2 weeks. My query is that it doesn't need any choke at all no matter what condition. This morning it was could enough to see my breath but again it didn't need any choke to start. It idles at low revs happily. However, this morning going through the village at neighbour friendly revs i pulled onto the main road and it spluttered really badly and ran onto 1 or 2 cylinders. I paddled my way across the road and pulled to the side. I was able to bring the revs slowly up and clear it fine. 30 seconds later i was on my way.

Im guessing its running lean because of not needing any choke and maybe was close to fouling the plugs up??? I did allow a good few minutes to allow the motor to warm up.

When downshifting it does pop and bang (music to my ears) from 6.5k to 5k revs.

Whats the recommendation for jetting changes etc with a change to that silencer?

Thanks

Starting with no choke is good
As for jets I have been recommended 4 x112 for my tyga twin.
Might be the same for yours ?
U have full tyga system or just can? If its just can then STD jets would be fine but I'm no expert.
Also in the service receipt u say 2 valve clearances needing doing? Have u checked them and sorted them out your self?

LUCAS · Post by **LUCAS** » Fri Sep 03, 2010 12:23 am

Harvd wrote:Yup theres a lot of pop and crackle in these cans
i ended up going for 115s after trying some 112s i also fitted some 0.5mm shims under the needles. This flattened out the midrange really well.

I should get a scanner and put my dyno run on here. Standard everything bar exhaust and carb jetted to suit. such a linear curve and 59 hp

Thanks Harvd that gives me something to go by maybe. Would be nice seeing the dyno graph

LUCAS · Post by **LUCAS** » Fri Sep 03, 2010 12:31 am

code2006 wrote: Starting with no choke is good
As for jets I have been recommended 4 x112 for my tyga twin.
Might be the same for yours ?
U have full tyga system or just can? If its just can then STD jets would be fine but I'm no expert.
Also in the service receipt u say 2 valve clearances needing doing? Have u checked them and sorted them out your self?

The 2 valve clearances out and all sorted was from a conversation with the previous owner. No written evidence/ detail of that on the receipt and im not one for taking things like that as the truth. May check them myself.

Its a standard system with just the Tyga silencer.

The motor has only covered 14000 miles which would help with starting. My CBR400 at 75000km not so good at starting!!

I will see if the problem reoccurs on another cold morning. Fingers crossed it wont!

code2006 · Post by **code2006** » Fri Sep 03, 2010 12:47 am

LUCAS wrote:
code2006 wrote: Starting with no choke is good
As for jets I have been recommended 4 x112 for my tyga twin.
Might be the same for yours ?
U have full tyga system or just can? If its just can then STD jets would be fine but I'm no expert.
Also in the service receipt u say 2 valve clearances needing doing? Have u checked them and sorted them out your self?
The 2 valve clearances out and all sorted was from a conversation with the previous owner. No written evidence/ detail of that on the receipt and im not one for taking things like that as the truth. May check them myself.

Its a standard system with just the Tyga silencer.

The motor has only covered 14000 miles which would help with starting. My CBR400 at 75000km not so good at starting!!

I will see if the problem reoccurs on another cold morning. Fingers crossed it wont!

Ok I wouldn't had tough u would new to change the jets if u have a STD system but I don't know much.
As for the service it would had been easy for mechanic to give the guy a call and say that he needs 2 replace 2 shims unless they didn't have any but I would give them another check if I was you just to be on the safe side