Triumphrat

Irishguy · 12-06-2012, 09:12 PM

Wow! That is a lot of difference! no wonder that I keep reading posts where one guy will say, "Hey, a 140 worked great for me!" and another guy will post, "I needed a 150."

There is no substitute for taking your bike to the dyno. Same as when I have built several turbo Miata's. You have to get a base line and then get the other data and work up from there.

I hope to be ordering some stuff next week.

Hey Everyone,

Please post links to websites where I can order, jets, needles and shims.

Thanks...

SCbonneville · 12-06-2012, 11:25 PM

Quote:

Originally Posted by Irishguy

Wow! That is a lot of difference! no wonder that I keep reading posts where one guy will say, "Hey, a 140 worked great for me!" and another guy will post, "I needed a 150."

There is no substitute for taking your bike to the dyno. Same as when I have built several turbo Miata's. You have to get a base line and then get the other data and work up from there.

I hope to be ordering some stuff next week.

Hey Everyone,

Please post links to websites where I can order, jets, needles and shims.

Thanks...

Mike at BellaCorse is a good source for the proper jets for CVK carbs

http://www.bellacorse.com/bce011-14.htm

15 bucks for a kit (42 pilots/145 mains & 4 shims) and you can get pairs of other sized mains (say 142's & 148's) for 6 buck per pair.... That's $27 for the pilots, shims and a good range of main jets. Add a set of 140's and 150's if you want... though the 142 - 148 set should cover you.

Tracking down needles is tougher... and Keihin has a butt ton of needles for their various carb models and you really need to know exactly which ones to order for the CVK's that Triumph uses. If you have a decent Triumph dealer near you, have them order you a set of "865" or NBZT needles... should be around 12 or 14 dollars for the pair, if I remember correctly...

The carb screw kit is a worthwhile upgrade... cheap too...

http://www.bellacorse.com/bce021.htm

Askari · 12-07-2012, 01:46 AM

Quote:

Originally Posted by Irishguy

Wow! That is a lot of difference! no wonder that I keep reading posts where one guy will say, "Hey, a 140 worked great for me!" and another guy will post, "I needed a 150."

There is no substitute for taking your bike to the dyno. Same as when I have built several turbo Miata's. You have to get a base line and then get the other data and work up from there.

I hope to be ordering some stuff next week.

Hey Everyone,

Please post links to websites where I can order, jets, needles and shims.

Think Forchetto posted a very sage answer to this varying setups. People perception as to what is good. It would seem that the window for tuning is quite wide. Rich/lean they still run good, it is when you start going too lean/rich that things change.
As mikeniva regularly points out unless you use a dyno or at least an A/F meter you are only getting in a ball park. Whether that is good, bad or accepatable is really up to the individual.

Thanks...

This is probably not of any use but this is where i got my jets/ shims from. As postage was just in an envelope it was cheap. I told them the sizes of jets i wanted, no of shims there next day.
http://www.showandgo.com.au/

Askari · 12-07-2012, 01:54 AM

Found this in my saved stuff. It is for a 32, looks pretty similar to a 36. Pics might help you to locate the jets etc.
http://myural.com/keihin_32cvk_disassembly.htm

SCbonneville · 12-07-2012, 08:32 AM

Quote:

Originally Posted by Askari

This is probably not of any use but this is where i got my jets/ shims from. As postage was just in an envelope it was cheap. I told them the sizes of jets i wanted, no of shims there next day.
http://www.showandgo.com.au/

Yes, Askari, there are any number of places that carry jets for the CVK's... Keihin or "oem equivalent"... The problem that can arise is that there are various incarnations of Keihin CV carbs that use different but similarly appearing jets... ie: "Harley CVK's" use different jets and needles than the ones used on Triumph "CVK's"...

Since Mike carries only the jets for the CVK's on the Bonnies, it just eliminates the chances of ordering the wrong ones... That is why I recommended going that route.

PS, the break down/rebuild link you posted is a good one... gives a good view of what you're looking at when servicing the CVK... I do have one minor point of contention though... His "verbiage" about only two reasons to access the top/slides of the carb... diaphragm tear and submersion? What about needle changing and shimming?

Irishguy · 05-06-2013, 10:27 AM

I just wanted to follow up on this thread in case anyone else is searching for info like I have been lately:

I got into the carbs and it turns out that the previous owner or previous tuner had installed 152 main jets. It has the stock needles and 3 shims under each needle. I forgot to take a look at the pilot jets.

Anyway, before I did anything I got the bike warmed up and took it up a long, mild incline on a nearby highway, took it up to full throttle and then slightly backed off to about 7/8ths throttle. There was no improvement at 7/8ths so I'm assuming from that, that the mains are sized about right.

Next I pulled it back into my shop and removed 2 of the three shims and took it back out for a spin. There was marked improvement in power from about 1/4 to 3/4 throttle and in the mid-range.

Next I pulled it back into the shop and took out the last shim, but just about that time my buddy showed up with some moonshine that he made and I don't remember much after that...

and I haven't had a chance to test it again.

My thoughts are that I will be even better. Here's to hoping.

Next up is to check the pilot jet. I'm 3 turns out, so my suspicion is that it is the stock 40.

bluesforchallah · 05-06-2013, 02:34 PM

Quote:

Originally Posted by Irishguy

I just wanted to follow up on this thread in case anyone else is searching for info like I have been lately:

I got into the carbs and it turns out that the previous owner or previous tuner had installed 152 main jets. It has the stock needles and 3 shims under each needle. I forgot to take a look at the pilot jets.

Anyway, before I did anything I got the bike warmed up and took it up a long, mild incline on a nearby highway, took it up to full throttle and then slightly backed off to about 7/8ths throttle. There was no improvement at 7/8ths so I'm assuming from that, that the mains are sized about right.

Next I pulled it back into my shop and removed 2 of the three shims and took it back out for a spin. There was marked improvement in power from about 1/4 to 3/4 throttle and in the mid-range.

Next I pulled it back into the shop and took out the last shim, but just about that time my buddy showed up with some moonshine that he made and I don't remember much after that...

and I haven't had a chance to test it again.

My thoughts are that I will be even better. Here's to hoping.

Next up is to check the pilot jet. I'm 3 turns out, so my suspicion is that it is the stock 40.

I'm now running 150 mains w/o shims, thrux needles (I understand stock '08 T100s came with Thrux needles) and 45 pilot jets. I was running 42 pilots like a lot of others after opening up the air-box and putting open flow pipes on, but it was getting an almost predictable hiccup at stops like so many others have said they were getting. So thru recommendation of another friend of mine, I upped the pilots to 45s and put the air mixture screw at 1.5 turns out. The bike is running a lot stronger at idle, the idle no longer fluctuates and I can give the bike a quick turn of the throttle with the RPM being much quicker to recover and most of all…no longer hiccupping. I haven't had it dyno'd, but I can tell just by the seat of my pants, it's a much better improvement.

Let us know how things end up.