Topic: Jets question (not about sizing)

[hondachopproject]

Hello,
I have a 76 CB 550 running individual foam uni-filter air filters. and open pipes.
I am running No. 100 main Jet and No. 38 Pilot Jet (samething as Slow Jet?).
It runs like crap. Dies after openning choke, won't idle. I assume I need to go to higher jets, possible 120 to 125 mains 40 pilots.
I called the local dealer (what a joke) and they said the 100 is ALL that I can get for this bike.
From reading here I know this can not be true.
Where can I get them. Do (other) Honda dealers stock them?
I have read about changing location on another jet? I am a bit confused on this and how it is done.
Any help appreciated,
Lee

[Pinhead]

Just look for jets for your carbs, not for your bike. I'll go out on a limb and assume you've got Keihin's, you could get them where I got mine:

http://www.crc2onlinecatalog.com/misc_carb_parts.htm#Main%20Jets

[hondachopproject]

Pinhead,
Thanks, yup Keihin's.
That makes sense, suprised parts man at dealer couldn't tell me that!
Thanks again,
Lee

[hondachopproject]

Hey Pinhead,
Just noticed you was from KC.
Glad to see more on list from this area.
Lee
Topeka

[400F_CaféKing]

You may also want to try adjusting your throtle needle.

[Pinhead]

Hey Pinhead,
Just noticed you was from KC.
Glad to see more on list from this area.
Lee
Topeka

LOL I bought my bike from a guy in Topeka, too!

[hondachopproject]

You may also want to try adjusting your throtle needle.

I am a bit new at this... I am not sure what is meant by throttle needle...or how to adjust it.
Can you give me a bit more info?
Thanks,
Lee

[hondachopproject]

LOL I bought my bike from a guy in Topeka, too!

LOL.....was it somebody from the list?

[Pinhead]

LOL I bought my bike from a guy in Topeka, too!

LOL.....was it somebody from the list?

I don't think so, I got it off eBay. $515 I think it was, delivered.

[mrbreeze]

Its pretty amazing what these dealership people know about bikes isn't it?

[Noel]

FWIW, you can drill your mains in increments with commonly available numbered bits. You will find people who will tell you it's a bad idea and that you will die -- or something like that -- but it worked for me, and if nothing else is a good bit cheaper than buying a half dozen sets of jets with which to experiment. Once you've found the correct size you can order it and thus avoid dying.

Although I am led to believe that pods and/or open pipes will also lead to death, but that's another thread I suppose.

[bryanj]

400/500 & 550 (except K£) use a push in jet that is VERY difficult to come by and expensive when you can ($10 EACH) as against the readily available screw in 750 type. You may well have to resort to drilling them BUT make sure you have a "Spare" set FIRST

[hondachopproject]

people who will tell you.....you will die -- or something like that -- 
Although I am led to believe that pods and/or open pipes will also lead to death, but that's another thread I suppose.

Guess I hven't seen that about drilling them. How could that kill you?

I may have to disagree though about the open pipes.....I beleive in the old saying "Loud Pipes Saves Lives"

[hondachopproject]

You may well have to resort to drilling them BUT make sure you have a "Spare" set FIRST

I do have a spare set. well kind of, the are in another set of carbs on another bike I haven't started on yet.

Bryanj and Noel..an tips on drilling these out? Does it matter which direction to drill from?etc.

[Noel]

Guess I hven't seen that about drilling them. How could that kill you?

I may have to disagree though about the open pipes.....I beleive in the old saying "Loud Pipes Saves Lives"

Just poking a bit of fun at some of the more conservative types around here. I figures the worst outcome of drilled mains is a set of ruined mains. As far as the open pipes, I do like that sound, but also have neighbors to consider. I'm running with no baffles in my SuperTrapp, but have left a bit of restriction at the end to try to keep the locals (and the cops!) happy.

[Noel]

As for spares, they can be had from http://www.crc2onlinecatalog.com/misc_carb_parts.htm#Main%20Jets (scroll to the middle of the page) in sizes from 98 to 150, for $3.25 each plus shipping. This seems like a fine deal, unless you need to experiemnt, in which case you may well be on the hook for $60 or more. Still not a huge amount of money, but...

I drilled until I found "rich", and then bought a single set of new jets one size smaller. Total cost for trying four different sizes with drill bits: $12.

For the complete run-down on the board's opinion of drilling, go to http://www.sohc4.us/forums/index.php?topic=3713.0.

Short version: some people think drilling isn't precise enough; that it can/will make oval holes and also that drilling changes the precise geometry of the inlets. Other people shrug and say "Well, I drilled 'em and they work fine, so I think you're overestimating how precise these things actually are."

My drilling technique was/is to chuck the bit in a vice, using some scraps of soft wood to prevent snapping the bit, and then gently turning the jet down onto it. As long as you're going up one size at a time, this seems to create no problems and results in a mirror-smooth interior surface. Just check for burrs and shavings before tossing them back into the carbs. Oh, and I ended up drilling from the inlet side as it seemed to make centering the jet on the bit a little easier, FWIW.

[eurban]

Getting back to his orginal question .  . . ..What is the stock pilot jet for the 550? I believe the early 750s used 40s and my 78 750ks stock size is a 35.  Perhaps you need to jet up on the pilot jet but perhaps with your current symptoms you should consider that your current #38 is way too big? 

[hondachopproject]

Getting back to his orginal question .  . . ..What is the stock pilot jet for the 550? I believe the early 750s used 40s and my 78 750ks stock size is a 35.  Perhaps you need to jet up on the pilot jet but perhaps with your current symptoms you should consider that your current #38 is way too big? 

eurban,
according to my Haynes manual 38 for 550 model 40 for 550 F model.
you say the 38 may be way to big? Again symptoms, bike starts(usually after a LOT of kicking), but dies when I try to open the choke. Earlier this summer I could ride it short distance but had to keep it fully or almost fully chocked.
Lee

[hondachopproject]

As for spares, they can be had from http://www.crc2onlinecatalog.com/misc_carb_parts.htm#Main%20Jets (

This is probably what I will do.
But first have to narrow down the problem...... to small of mains, to large of pilot jets as eurban mentioned, or wrong color paint...... right now how knows!
Any links for pilot jets?
Lee

[Noel]

I spent a long time looking for pilots and never found any. With screened stacks and almost completely unrestricted pipes, I was able to get my bike to start and idle perfectly by turning in the air screws all the way. Am not sure about the 55, but on the 500 the screws still flow air even when turned all the way in.

So hopefully not talking out of my arse -- the bikes are very similar -- I would leave the pilots alone for now, turn in the airscrews to maybe 1/2 turn from bottomed, and switch to 120 mains. Assuming your carbs are squeaky clean -- and the rest of the bike is in proper tune -- this should get you pretty close if not perfect. Good luck!

[mrbreeze]

After rereading this post,I noticed no mention of carb sync.I don't care if the sucker runs and has clean bench synched carbs.Its going to make all the difference doing a proper carb sync.

[hondachopproject]

After rereading this post,I noticed no mention of carb sync.I don't care if the sucker runs and has clean bench synched carbs.Its going to make all the difference doing a proper carb sync.

The carbs were synced by Honda prior to Hardtailing and modifications(open pipes, individual air filters)

[mrbreeze]

So now the fun begins! You have to seperate all of your throttle settings but first.you have to have compression(valve timing and adjustment).You have to have a properly timed spark and you have to have a proper air/fuel mixture.There are many things that can throw a monkey wrench into the machine but with patience,determination,a fair mix of tools,A few books don't hurt,the people on this site,and.......oh yeah......you gotta have a brain also!!!!!!(not directed at anyone personally of course!!!!)If you do any of these things without the rest of them.....you will more than likely not have the machine you are striving for.Happy Motoring!!!!!!

[hondachopproject]

Well I went out and finally got her started (but running like crap) and this is what I ran into:
I noticed 2 of the exhaust ipes were cold.
  So I Tore into it and found :
1. one outlet on the petcock was clogged. Unclogged it.
2. Plugs were terrible fouled. Cleaned them, they are new.
3. Broke #2 plug cap trying to remove it. Replaced it. Honda wanted 16 something, but it from a local  independant shop 3 dollars. NGK's
3. And probably most important slowjets clogged or nearly clogged. Cleaned them.
4 Dead battery. Charged it.

Now she fires on first kick AND....now idles without the choke on!!!!!!!!!

Grin

Still think I will have to put 120 or 125 main jets in though.
Hopefully I can test ride it tomorrow.

[mrbreeze]

Good for you man!!!!Now you are getting the satisfaction of making one of these bad ass machines run!!! If it still ain't right,you can keep trying different combinations until you are satisfied with the way she runs.Just keep notes of what you did so far and any adjustments or part changes you make.If it runs better...great.If it runs worse,go the other way.What pissed me off when I did mine was the fact that every main jet change costed me $28 (4x$7).Every needle position change costed me time (to remove carbs and try different needle setting). The end result when it runs good through all throttle settings will put a major #$%* eating grin on your face that makes it all worth it!!! After you get it right....get the carbs synched and you are there my man!!!! Oh...and by the way....now that you you have your slow jets cleaned out,I wouldn't worry about resizing them. I kept my stock 40's and it idles fine after warm up. The mains is the ones to be concerned with.