Despite some cans of Seafoam recently my '02 still won't run eagerly when cold, seems to be searching for a steady idle even when warm, and the gas mileage has dropped to 39mpg from the usual average of 44mpg. The current setup is 132 MJ's, stock 40's at 2.50 turns out, and new Nology coil and wires.
Checking at Hermy's, they offer the stock 40 pilot jets but at $33 bucks each. Newbonneville offers pilot jets at $7 each, which is great but 42's are the closest option. I've read a lot of discussion on the merits of 40's/42's for our bikes, and hope I've concluded correctly that the 42's would be fine but with perhaps an additional turn out. Please correct me if I'm wrong.
I'm putting in new pilots because the previous owner did literally no maintenance and the bike sat unused for years. After that it'd be hard to imagine those little rubber bits would still be serviceable.
Lastly, Newbonneville sells neat idle air adjusters with accessible knurled handles, but I can't find any oem style even from Hermy's which I'd prefer. Again because of the deteriorated gasket issue I thought I'd better replace them.
The gas tank appears to be clean, I've drained some gas to see if there's any particulate or color but it's clean.
Thanks Callumity, yes, ultrasonic would be best but not certain there's anyone local here to do it. Jenk's is great, and I know that even with TORS on I'm outside their recommended setup. But each bike is different of course, and on my previous '04 I had it dyno-ed with 138MJ's, TORS and with 1 shim and it registered just right. The gas mpg's was also good usually touching 50mpg. I can always back off later but it ran so well I'd like to feel that agin.
I am running 42's and my carb Bonneville is bone stock. I could never get rid of the off idle and choppy acceleration [ slight but there ] with the stock 40's. Going to 42's really helped the cold blooded nature and immensely improved the off idle through mid acceleration smoothness.
You can go to Rockymountainatvmc.com for carb jets. You need to look them up for the carb you have, not the bike. They have everything jet wise you will ever need. Great people also !
They also have air screw adjusters that I think would work on our bikes but never looked into it very far. I wish I had a set since just a slight adjustment as air temps change is nice to have. I have them on all the other bikes just not the Triumph.
Thanks Back2-2, if you're running 42's successfully I'm sold. I'll look at Rockymountain for the idle air screws, that's the last piece of the effort. Thanks again.
The knurled idle needles are great. Got mine from CV products. Less expensive than other sites. Soaked my bodies in naptha (from Lowes paint dept.) careful though, it flashes off quick. You'll want a sealable container of some kind.
I hadn't thought of naptha, but the reports/reviews are good for carb cleaning if handled carefully. I'll look at CV Products, thanks, another new on on me. I see you're running 42's also? With you and Back2-2 having them it must make sense.
The 42's got rid of all the popping on decel and down shifting. Also I only need about 1 3/4 turns on the idle screws so it isn't nearly as rich on idle.
Yes definitely going to 42's as a cure for the cold running/dying symptom. I spoke with CV Products, but 'no' on pilot jets for Bonnies I was told. I found a page on Rockymountain.com that shows Keihin pilot jets, but I'll have to speak with someone from Triumph whether any of these shown would be correct.
I run 42's on my Scrambler and also went with a 125 main and Thruxton needle while it was all apart.
The bike pulls very well throughout. No popping etc.
I too looked into the knurled adjusters BUT when comparing the originals to the aftermarket offerings, I noticed that the "tip" on the OEM is about twice as long as the replacements. Once you remove yours, be particularly observant of the length of the tip when browsing for replacements.
FWIW, after further thought, I retained the originals - cutting a small slot to allow adjustment in situ using a straight bladed tip sitting in a quarter drive, 1/4" socket. (It's just as easy to pick up the correct D shaped socket for less than $10 too.)
Yes, finding exact replacements is the job. I found this idle mix screw on Ebay, which in the description says will fit Keihin CVK36 carbs on Triumph Bonneville.
But trying to compare it, for example, to NewBonneville's replacement picture is difficult. I'll have to wait for both to be on the table side by side.
On my existing idle air screws, I can manage fairly well with a small screwdriver I modified, but it's easy to loose touch/count especially when working on a hot engine.
I'd love to strike onto a supply of the tiny rubber gaskets for this rebuild project, I suspect mine are likely shot after 15 years, and good gaskets are key.
I tried ti find my RM part number for the 42 pilot jets for you. It seems to be packed away with my Triumph manuals as I am prepping for a move. I do not recall it being anything hard to find - they are just Keihin CV pilots. I even recall there was a picture of them.
For the little tool you made - I did the same and marked it on the side so you can easily count turns and see where you are.
The brass aftermarket adjusters are super nice but I'm pretty tight with the buck so never sprung for them.
Thanks much for your efforts Back2-2. I bought the 42's from NewBonneville at a good reasonable price, but like you, balked at nearly $100 for two knurled idle air knobs, despite their user appeal. The two I bought from Ebay, http://www.ebay.com/itm/231932922957, do state they're good for Keihin CVK 36 carbs, so about $40 for the pair. I'll get back to you if they're right.
Beyond my other limitations and unruly thoughts, seeing so many item costs disconnected from their real value has become another rant for me.
Sounds good - But I did find the info.- just now in case anyone else needs it.
From rockymountain the product # is : 1326320004 and the Mfg. # 019-813 they are titled : Keihin N424-25B Series Pilot Jet 42.
Price was 6.99 each. For what it's worth if you have never done business with RM they are incredibly helpful and really, really good to deal with. They are in Payson Utah - It is on hte bucket list to stop in there some time. I have driven by while travling a few times & never taken the time to stop.
Hope that helps.
Look forward to hearing your review of the air screws !
Thanks, yes, got them bookmarked. Those are good prices, and with dealers falling like leaves good online sources are critical. This week on the air screws I hope, I'll get back of course.
I called CV Products for the 'knurled' needles but was told they didn't have them. I'll see how this Ebay deal works out, and if they're not as I hope I'll try CV Products again.
I'm using the 42's and I'm only out 1 turn. Picked up the knurled air screws from Newbonneville.com. They were expensive for what they are. Running ARC and pods, 140 mains, only getting 39 mpg.
A quick reiteration of my earlier post .......for £50/$80 plus delivery a cheapie uktrasonic bath (3 litre or bigger) will hold a pair of stripped carbs and all manner of other stuff and do a remarkable job using water and soap.....brilliant if you buy the inexpensive metal cleaner. I bought mine to clean varnished carbs and it has since done all manner of jewellery, brake parts, furnace oil jets etc. It is one of those tools like a Dremel or a multi-cutter you wonder why you never got sooner. Beats a hard steel wire in a soft jet and does a far better job.
OP - your original question was: "and hope I've concluded correctly that the 42's would be fine but with perhaps an additional turn out. Please correct me if I'm wrong." As others have noted, you'll need less turns out, not more. More turns out will make it way too rich. I installed the 42s years ago (3+ turns out on the stock 40s was still too lean), about 1 3/4 turns out worked for me. I have read that 1 turn out on 42s is about equal to 3 turns out on 42s.
Looking back at my notes when I set up my carbs last July, reminded me of several points....
I made a template to set the floats from a piece of scrap aluminum sheet, which I then used to ensure that the float heights (at 17mm) were equally matched.
You could also make one from a piece of card stock. Measure the width across the float bowl sides. Add a cm to each side to allow enough material to easily "stand perpendicular" on the carb body. Measure the width of the the floats and cut out that space plus a few mm each side, up to height of 17mm horizontal to the float chamber. You should now have an aperture which, when placed over the floats will give you an even 17mm datum to adjust the floats to.
I swapped the original 40 pilots for 42's.
I replaced the original needles (N3RL) with Thruxton needles (NBZT).
I actually used 122's for the main jets (previously I thought I'd used 125's).
I finally set the D-headed adjuster screws at 2.5 turns out after a little trail and error, beginning at just 2 turns out.
I'm glad I triple-checked that the inlet runners (the rubber sleeves between the airbag and the carbs) were in good condition. After close inspection, I discovered a previously undetected tear in one of the rubbers and so replaced both with new ones.
I also removed the snorkel, opened the aperture into the airbox to within 5mm of the oval lip which presses against the foam seal on the air filter on the inner face of the cover and removed the baffle. A previous owner had already removed the air injection.
I'm very satisfied with the performance.
No popping, good idle and strong response throughout the throttle range.
Sorry for not getting back to your good info here. I'll do that card stock trick, I've never measured float height yet so I'm sure it's time. The 42's will be going in shortly, and maybe I'll try the NBZT needles. I've read about them but still not certain of their effect.
I'm currently running 132 MJ's, I had thought of going to 138's with one shim which ran perfectly on my old '04, but that's far larger than yours, and outside of the usual carb spec sheets. I've got the 138's, and some 125's on the shelf so lots to experiment with.
Good starting point with those 42's is one turn out and then maybe not more then 1.5 turns to be in the ball park.
40's are set at 3.5 turns from the factory which is equal to about a 42 with 1 turn or there about. All you are doing with a 42 with the less turns, making it a tiny bit more rich then a 40 with 3.5 turns. Gives better cold starting and helps cool the motor at the lights. Little richer pick up from the idle. Not much difference other then the cold weather advantage when starting. It also helps with de-excel pop.
All great info. The only thing I would like to add is the way of measuring float height with clear tubing off the bowl drain port and running it along the bowl side. With the bike upright this is the actual float height measurement. It really makes it easy to see what you got. It is spelled out in the manual on the way to set it up.
Also, don't do to many things at once so you know what really works and what does not.
Just a few thoughts for you. Good luck and look forward to how it all goes for you.
Also, don't do to many things at once so you know what really works and what does not.
Top advice, thanks Back2-2. Yes actually that clear tube method seems far easier and quick. Perhaps when I've got the carbs out the adjusting 'pin' action will become apparent.
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