Thanks for taking a minute to read this post and helping if you're able.
I have a 2008 Triumph Scrambler 900cc. I purchased the bike 2nd hand a while back and have been riding and loving it since. It's my 1st scrambler and probably my only for the foreseeable future, I love this bike.Some background on me is my only other experience with carbureted bikes are vintage Vespas, and a 2008 DR650, both of which I did not upgrade jets or reconfigure airboxes.
EDIT2: This is a CVK 36? carb, I live in NY/NYC at 20-50ft above sea level.
Before I get started, I just want to let the 'forum search' advocates know that I did some searching and read as many relevant posts as possible before opening a new thread (Because there's a limit to how much internet we can use).
The bike currently has 2 K&N Unifilter cones installed, the airbox baffle is removed and the airbox was cut by the previous owner (pictured). I installed the VW exhaust silencers and it rode the same as with the stock exhaust but my pipes were pretty blue and seemed to be getting worse, they also seemed to run a lot hotter because with the stock exhaust I didn't notice the head on my knees as much. The bike ran fine to the best of my knowledge, okay pickup at low speed and same at high speed.
Some light research led me to the idea that I need to rejet my carb, I'm not sure where, but I decided on 135 mains and 42 pilots. The mix screw was turned 2.5 turns out, I turned it in till it seated, and back it out 2.5 turns as I've read on here is a good baseline. I installed the jets last night and fired the bike up this morning, it started right up without choke and was running fine but the idle seemed really low (I did not touch the idle screw, BUT, the bike did idle low before but not enough to raise concern). I blipped the throttle and it died.
I fired the bike back up this time it needed the choke, I left the choke on and it idled like it was at 1/2-3/4 throttle, I pushed the choke in and it dropped back down to very low. I gave a little steady throttle (1/4 to 1/3) and it was ok. Let off the throttle, back down to very low idle, then it cut out.
All of this was done with the 'scrambler 900' side covers mounted against the air filter pods on the carbs. I'll be working on this a little more later today but wanted to some advice if anyone has it. I read the 'Tuning Notes PDF by Jenks' and it gave me a better understanding of my carb. From that PDF I feel that the 135's may be a tad too large and I should ideally be at a 120, or possibly a 125 with the way my airbox is setup. I'm not sure whether or not I may need to change my needle as well.
Lastly, I did all this without removing the carbs, I disconnected them from the manifold and turned them side ways like in this blog :Re-jetting the Keihin CVK Carburetor | Triumph Bonneville - A Personal Moto Blog
Thanks for the help.
-HabibiKnows
Edit: Im going to try turning in the pilot screw .5 turn and see how it fares this afternoon. Will provide updates to this tread as I troubleshoot the problem.
I have a 2008 Triumph Scrambler 900cc. I purchased the bike 2nd hand a while back and have been riding and loving it since. It's my 1st scrambler and probably my only for the foreseeable future, I love this bike.Some background on me is my only other experience with carbureted bikes are vintage Vespas, and a 2008 DR650, both of which I did not upgrade jets or reconfigure airboxes.
EDIT2: This is a CVK 36? carb, I live in NY/NYC at 20-50ft above sea level.
Before I get started, I just want to let the 'forum search' advocates know that I did some searching and read as many relevant posts as possible before opening a new thread (Because there's a limit to how much internet we can use).
The bike currently has 2 K&N Unifilter cones installed, the airbox baffle is removed and the airbox was cut by the previous owner (pictured). I installed the VW exhaust silencers and it rode the same as with the stock exhaust but my pipes were pretty blue and seemed to be getting worse, they also seemed to run a lot hotter because with the stock exhaust I didn't notice the head on my knees as much. The bike ran fine to the best of my knowledge, okay pickup at low speed and same at high speed.
Some light research led me to the idea that I need to rejet my carb, I'm not sure where, but I decided on 135 mains and 42 pilots. The mix screw was turned 2.5 turns out, I turned it in till it seated, and back it out 2.5 turns as I've read on here is a good baseline. I installed the jets last night and fired the bike up this morning, it started right up without choke and was running fine but the idle seemed really low (I did not touch the idle screw, BUT, the bike did idle low before but not enough to raise concern). I blipped the throttle and it died.
I fired the bike back up this time it needed the choke, I left the choke on and it idled like it was at 1/2-3/4 throttle, I pushed the choke in and it dropped back down to very low. I gave a little steady throttle (1/4 to 1/3) and it was ok. Let off the throttle, back down to very low idle, then it cut out.
All of this was done with the 'scrambler 900' side covers mounted against the air filter pods on the carbs. I'll be working on this a little more later today but wanted to some advice if anyone has it. I read the 'Tuning Notes PDF by Jenks' and it gave me a better understanding of my carb. From that PDF I feel that the 135's may be a tad too large and I should ideally be at a 120, or possibly a 125 with the way my airbox is setup. I'm not sure whether or not I may need to change my needle as well.
Lastly, I did all this without removing the carbs, I disconnected them from the manifold and turned them side ways like in this blog :Re-jetting the Keihin CVK Carburetor | Triumph Bonneville - A Personal Moto Blog
Thanks for the help.
-HabibiKnows
Edit: Im going to try turning in the pilot screw .5 turn and see how it fares this afternoon. Will provide updates to this tread as I troubleshoot the problem.
