Author Topic: How much does rejetting cost? (Read 9808 times)

jamesv220820 · « **on:** February 15, 2009, 03:59:11 PM »

i have a 350f im restoring and some parts i am going to order say that the bike will most liekly have to be rejetted
still new to restoring how much should that cost?
and should i rebuild the carbs before i get the rejetting done?

moham · « **Reply #1 on:** February 15, 2009, 04:05:29 PM »

What parts require re-jetting? If you are serious about restoring, then rebuilding carbs will be at the top of the list. Plan to spend a minimum of $50 to rebuild carbs.

TwoTired · « **Reply #2 on:** February 15, 2009, 04:11:40 PM »

A "restoration" to stock should only require the stock components, including the jets in the carbs.

jamesv220820 · « **Reply #3 on:** February 15, 2009, 04:16:26 PM »

aftermarket exhaust and K&N air filters say rejetting might be required

TwoTired · « **Reply #4 on:** February 15, 2009, 04:27:40 PM »

Quote from: jamesv220820 on February 15, 2009, 04:16:26 PM

aftermarket exhaust and K&N air filters say rejetting might be required

Then you aren't restoring the bike. You're just returning it to operating condition. Nothing wrong with that, though.
Open exhaust and filtration that raises the carb throat pressure, usually means larger metering orifices/adjustments int the carbs.
If the carbs are gunked up, then they need cleaning. If they are clean, then it's just adjusting and jet size changes. Look inside to determine the cleaning needs.
Most likely you'll have to richen up the idle, to get descent throttle response from down low (perhaps only with the idle bleed screws), possibly raise the slides needles, and maybe a larger main jet.
If you aren't using a dyno and getting a fuel map, then find a test track, some extra spark plugs, and learn to read spark deposits for combustion conditions. Then test and try, till it works as you wish it to. Takes patience and perseverance.

Cheers,

333 · « **Reply #5 on:** February 15, 2009, 04:35:59 PM »

+1 on the reading of the plugs. And you are going to have a harder time of it because of where you live. The higher altitudes compound the issue. Less air will affect the jetting. But if the bike has spent it's whole life in your area, it may not still be stock. The jets have numbers on them, so it will be easy to tell.

jamesv220820 · « **Reply #6 on:** February 15, 2009, 04:49:35 PM »

cool thanks for all the help

james

cb650 · « **Reply #7 on:** February 15, 2009, 05:01:40 PM »

You can do it yourself for the price of jets. Or you can take it to a shop that charges a bunch for a semi good job.
Also for the altitude here regetting would be better. Regardles of what was stock. Dont let the "experts" tell you bigger at our altitude either.

TwoTired · « **Reply #8 on:** February 15, 2009, 05:14:47 PM »

Quote from: cb650 on February 15, 2009, 05:01:40 PM

You can do it yourself for the price of jets. Or you can take it to a shop that charges a bunch for a semi good job.
Also for the altitude here regetting would be better. Regardles of what was stock. Dont let the "experts" tell you bigger at our altitude either.

The only caveate I have about this, is that ideal jetting for altitude usually means the engine runs lean at sea level. No issue around town, but if you take a trip... You might wind up with a hot, melted motor.

Cheers,

cb650 · « **Reply #9 on:** February 15, 2009, 06:21:42 PM »

If you look at his location he is in denver colorado. Mile high+++++ lowest part of the state is 3500. Less air less fuel = smaller jets. Stock jets are for sea level.

masonryman · « **Reply #10 on:** February 15, 2009, 06:34:26 PM »

I am getting ready to try this myself, I just bought 5 sets of jets and 2 sets of exhaust gaskets from Z1 I put pods and a custom exhaust on a build project and have not even started it yet.

The jets are just a little of $1.00 each at z1

Good luck

friedfish80 · « **Reply #11 on:** February 15, 2009, 07:57:51 PM »

You got a link for where you picked up your jets?

Does anyone have any experence with the glass sighted spark plug for tuneing. The site that sells the Morgan carb tune sells this sparkplug that's glass so you can see in the combustion chamber and "tune" by the color of the fire in the chamber. Is there any truth to this method?

jamesv220820 · « **Reply #12 on:** February 15, 2009, 08:00:47 PM »

Quote from: cb650 on February 15, 2009, 06:21:42 PM

If you look at his location he is in denver colorado. Mile high+++++ lowest part of the state is 3500. Less air less fuel = smaller jets. Stock jets are for sea level.

cool ya the bike will stay in denver for awhile probably 6 months then ill send it down to tampa florida or ride it down there not sure yet so i guess i would have to get it rejet again but for now ill rejet it for best performance in a high altitude

jamesv220820 · « **Reply #13 on:** February 15, 2009, 08:13:20 PM »

Quote from: cb650 on February 15, 2009, 06:21:42 PM

If you look at his location he is in denver colorado. Mile high+++++ lowest part of the state is 3500. Less air less fuel = smaller jets. Stock jets are for sea level.

smaller huh, well i was just was gonna order a keyster carb rebuild kit so are you saying those jets are gonna be a waste of money ?

http://cgi.ebay.com/ebaymotors/FOUR-Honda-CB350-F-Carb-Rebuild-Kits-Keyster-Kit-CB350F_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a1Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem110348966273QQitemZ110348966273QQptZMotorcyclesQ5fPartsQ5fAccessories

thanks

mrbreeze · « **Reply #14 on:** February 15, 2009, 08:16:10 PM »

Quote from: cb650 on February 15, 2009, 06:21:42 PM

If you look at his location he is in denver colorado. Mile high+++++ lowest part of the state is 3500. Less air less fuel = smaller jets. Stock jets are for sea level.

Stock jets are for sea level...............so when you take a stock bike with stock jets up to the mountains......just how high can you go before you have probs. with air/fuel mixture?
Oh.......and the main question.........How much does it cost to jet?
My experience tells me its alot less if you know what you're doing.The expense of working on these bikes comes two fold.....Parts and Time!!!!

masonryman · « **Reply #15 on:** February 15, 2009, 08:16:36 PM »

www.z1enterprises.com

You need to clean your carbs and see how it runs, and find out what size jets are in it

jamesv220820 · « **Reply #16 on:** February 15, 2009, 08:21:22 PM »

Quote from: masonryman on February 15, 2009, 08:16:36 PM

www.z1enterprises.com

You need to clean your carbs and see how it runs, and find out what size jets are in it

very nice site thanks masonryman i was wondering where i could find the decals theyve got alot of stuff for em

thanks

james

TwoTired · « **Reply #17 on:** February 16, 2009, 02:06:47 AM »

Quote from: cb650 on February 15, 2009, 06:21:42 PM

Stock jets are for sea level.

What makes you say that? Do you have a Honda directive for that statement?

Given the ideal mixture ratio changes with temperature, altitude, and humidity, and Honda sold to everywhere in the world, why would they set up the stock bike for ideal operation at only sea level altitudes?

I always thought they set up stock ratios for about 2000 Ft as a reasonable compromise. So, it runs a little leaner at lower altitudes, and a bit richer at higher altitudes.

Is there a Honda directive I missed?

333 · « **Reply #18 on:** February 16, 2009, 07:20:42 AM »

It seems to me that the early micro fiche actually stated something about altitude regarding the "optional" jets.

dummkauf · « **Reply #19 on:** February 16, 2009, 10:44:12 AM »

I haven't seen anyone respond with prices yet, but jets should cost you about $20. I've seen jet kits running upwards of $100, however if you know what size you need, just go to a honda dealer and get just the sizes you need and skip the kit.

I just picked up a main and a primary for my Buell this afternoon and it only cost me $5.36 for both, and that was Harley dealer prices, probly could've gotten them for $3 online somewhere

.....note that this is a thumper so I only needed one set as opposed to 4 for a CB.

heffay · « **Reply #20 on:** February 16, 2009, 10:54:16 AM »

Quote from: TwoTired on February 16, 2009, 02:06:47 AM

Quote from: cb650 on February 15, 2009, 06:21:42 PM
Stock jets are for sea level.

What makes you say that? Do you have a Honda directive for that statement?

Given the ideal mixture ratio changes with temperature, altitude, and humidity, and Honda sold to everywhere in the world, why would they set up the stock bike for ideal operation at only sea level altitudes?

I always thought they set up stock ratios for about 2000 Ft as a reasonable compromise. So, it runs a little leaner at lower altitudes, and a bit richer at higher altitudes.

Is there a Honda directive I missed?

no... but there is a class on tact that you missed.

and yes... i would agree that if you live at or in the rockies and intend to ride in them... you must constrict the flow of fuel in order to match the restricted air. its a simple formula. i've never read a directive for anything, i don't think... although, i have read many manuals and suggested carb settings for dealing w/ altitude.

also, 2000 feet above sea level isn't even close to how high we are!!!

TwoTired · « **Reply #21 on:** February 16, 2009, 12:39:15 PM »

Quote from: heffay on February 16, 2009, 10:54:16 AM

no... but there is a class on tact that you missed.

Attending class, and absorbing covered material are two different things... as is clear you've experienced.

Quote from: heffay on February 16, 2009, 10:54:16 AM

and yes... i would agree that if you live at or in the rockies and intend to ride in them... you must constrict the flow of fuel in order to match the restricted air. its a simple formula. i've never read a directive for anything, i don't think... although, i have read many manuals and suggested carb settings for dealing w/ altitude.

also, 2000 feet above sea level isn't even close to how high we are!!!

My airplane is carbureted, and normally aspirated, as is the SOHC4. It has a mixture control knob in the cockpit that is pilot operated. The operator's manual clearly states that mixture control leaning procedures begin above 5000 feet. More importantly, it stipulates full rich setting for decent below 5000 ft.
The Cessna 152, favored as a primary trainer to develop operational habits of pilots, uses 3000 Ft as the point when mixture control becomes significant, above; lean for peak RPM, below; full rich.

Forgetting this control on descent (leaving it leaned while landing) has danger in the event of a go around. Landing approaches are made with little or no power. A Go-around requires full power, and if the engine is still leaned for 7000 ft altitude, you get no power. (BT,DT) There are quite a few dented dashboards where the pilot has rammed the mixture control full forward, to regain engine power. And then, a permanently etched action made into the mental checklist of the pilot for decent procedures. (Brown pants are advised during pilot training.)

Anyway, despite the extremist aura that you wish to project, 5000 ft isn't extreme for thousands of airplanes that routinely fly above that altitude, albeit WITH a mixture control.

The point is, unless you absolutely must have maximum power, altitude effects don't really become interesting until 4000-5000 ft altitudes are achieved. And as I pointed out, ideal mixtures at or above 5000 are NOT good for lowland hot operation.
So, if you tune your bike for high altitudes, just remember to keep it there. And, don't be surprised if a bike that's peak tuned for altitude suddenly stops working ($) while driving toward Florida. A bike tuned for Florida, will likely tend to foul plugs in Denver or above. But, replacement plugs are way less $.

Do what you want. Just be aware of what you are doing.

Cheers,

heffay · « **Reply #22 on:** February 16, 2009, 12:46:32 PM »

but you didn't say that in the beginning two tired. not at all.

oh, here, sory... i almost forgot.

friedfish80 · « **Reply #23 on:** February 16, 2009, 01:00:28 PM »

Ok let's play nice around her

heffay · « **Reply #24 on:** February 16, 2009, 01:24:49 PM »

just banter... maybe 2tyred knows that by now.
if not he's a lost cause.

either way he disburses valuable information like its, well, valuable.

choke levers work well in the mountains... as does rejetting.

i would pay someone 50 bucks to do it for me as i looked over their shoulder... if they really needed the money. otherwise, i'd just save myself the trouble and money.

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Author Topic: How much does rejetting cost? (Read 9808 times)

masonryman

masonryman