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GT550 LMNAB Needle Jet

Posted: Mon Mar 31, 2014 5:50 am
by Vintageman
Hello,


Does anyone have a 174 series Needle Jet and can take some measurements of its length and shoulder thickness... for example. Optionally, compare it to another series side by side like the 159 or whatever. Take a picture so I can see as well please.

Looking for a possible replacement series since this one is obsolete.

Thanks

Re: GT550 LMNAB Needle Jet

Posted: Wed Apr 02, 2014 12:50 pm
by Vintageman
Nobody has one loose?

I suppose not.

All in carbs running in your bikes.

I again must have had these (have complete set of carbs in pieces) just what the 7734 did I do with them?

What series did the Kaw H1 use?
What series did the Yam R5 use?

Re: GT550 LMNAB Needle Jet

Posted: Wed Apr 02, 2014 1:51 pm
by tz375
According to my notes, R5 used a 169 series. That would be the Primary version of a #175, but I don't have one or the dimensions.

Re: GT550 LMNAB Needle Jet

Posted: Wed Apr 02, 2014 1:53 pm
by yeadon_m
I'm afraid so - those I have are in my carbs and on the bike (550B). As its going well for now I don't want to dismantle purely for measuring purposes. But, if I should have them apart later this year - as is quite possible - I'll be sure to take pics and measurements.

Mike

Re: GT550 LMNAB Needle Jet

Posted: Wed Apr 02, 2014 2:04 pm
by jabcb
This eBay retailer has NOS Mikuni needle jets for the GT550B.
http://www.ebay.com/itm/MIKUNI-NEEDLE-J ... 1031474530

Some chance they might have the ones you need -- you should ask them.

Re: GT550 LMNAB Needle Jet

Posted: Wed Apr 02, 2014 4:55 pm
by Vintageman
Thanks guys

yeadon_m.

No problem. Someday someone should measure.

I do recall the ones in my carbs were wasted. I doubt I threw away… but can’t find now. For if mine were the O8, as you noted, the later model years were larger hole and I am sure I could ream next size or two up. That’s what a reamer is for and that material is so soft, and the length of the metered area inside is not long at all it has worked well in the past for me .. shinny and smooth. Your not believing me, I can tell.

You and your dang GT550 carbs onto the GT380 got me here. I never thought the GT380 cyls had over a 28mm opening stock. I'll still plan to bore my spare 24mms to 26mm. waiting for my adjustable reamer to come in. It’s a bit like brain surgery, I have done it, but I am no surgeon.

Tz375 and jabcb
I doubt the 169 is a 174 equivalent? The 169 was claimed to be equal to 172 series... it's not as some of us have learned. So I think maybe R5 has a 172 series like GT250A with its 28mm carb?

Well off to (“Help”) pull the spindle out of a 2002 Saturn SL2 (son’s car). Front wheel bearing failed again. This time I am going to press the new one in myself

How about the H1 you Kaw guys what series. Mabybe I should ask Ivan I think he has a kit for H1?

Re: GT550 LMNAB Needle Jet

Posted: Wed Apr 02, 2014 5:00 pm
by jabcb
Oops. Had the wrong link.

GT550B needle jets with the Suzuki part #:
http://www.ebay.com/itm/Suzuki-1977-GT5 ... 0519442161

Re: GT550 LMNAB Needle Jet

Posted: Wed Apr 02, 2014 6:20 pm
by Blokhead
This probably doesn't help, but I run the 159 series in my 73 GT750. They are identical to the original 188, except they are threaded for the small hex main, instead of large round.

Re: GT550 LMNAB Needle Jet

Posted: Wed Apr 02, 2014 10:00 pm
by tz375
Blokhead,
Correct about 188 and 159 series.

Vintageman,
I have note here that ways that 172 fitted to 550 and 250 after 74 was replaced by 169 and I think that story came from Mikuni jet sellers, so it may be right but may also be wrong....We know that Mike Y has told us that his 550 has 174 series fitted to his late model 550 carbs. I doubt that 169, 172 and 174 are all the same though

175 (bleed) and 169(Primary) fit the same 28mm carbs on Yamaha twins but I don't have a 174 series on hand to measure. I'm sure I have a 169 AND 175 & 176 here somewhere, but as I said no 174 to compare to.

Re: GT550 LMNAB Needle Jet

Posted: Thu Apr 03, 2014 6:00 am
by Vintageman
tz375 wrote:Blokhead,
Correct about 188 and 159 series.
Almost perfect. The air inlet hole is a little smaller on 188, more round where 159 more oval. When no air jet dominating this changes things just a little, but I have had no issues.... you may have to tune a little. e.g. clip pos, pilot circuit or +/- needle jet orfice size ... if anything at all

Tz375 remember the 169 had an 0.040" thinner shoulder tahn 172 and sets lower. So we and others thought e can just shim up... but watch out, the air hole may partial blocked. You could elongate if it does, but did not try.... Jack knife was dull?

Yeah, we need a 174 to check and must be different question is where. I could drop a 172 into my later 550 ad see how it looks. I will. But, these are obsolete too :(

What series is the H1....maybe that question needs to be placed on Kawasaki forum

Re: GT550 LMNAB Needle Jet

Posted: Thu Apr 03, 2014 7:40 am
by tz375
jabcb wrote:Oops. Had the wrong link.

GT550B needle jets with the Suzuki part #:
http://www.ebay.com/itm/Suzuki-1977-GT5 ... 0519442161
Can anyone read the numbers on those? At that price they are not cheap but if someone needs a set, now would be a good time to garb a few.

Re: GT550 LMNAB Needle Jet

Posted: Thu Apr 03, 2014 7:47 am
by jabcb
tz375 wrote:
jabcb wrote:Oops. Had the wrong link.

GT550B needle jets with the Suzuki part #:
http://www.ebay.com/itm/Suzuki-1977-GT5 ... 0519442161
Can anyone read the numbers on those? At that price they are not cheap but if someone needs a set, now would be a good time to garb a few.
Ask the seller for a pic.

Re: GT550 LMNAB Needle Jet

Posted: Thu Apr 03, 2014 8:27 am
by Vintageman
I asked.

They look real short and I think I see 192. If so that is early GT550.

and P-4 is large

We'll see

Thanks jabcb

Also, Per Ivanperformance H1 is a 172 series. I'll try a 172 later to see how it fits GT550

Re: GT550 LMNAB Needle Jet

Posted: Thu Apr 03, 2014 8:56 am
by Vintageman
I asked twice and refuses to check. Wants to sell based on part# only.

Looks like 192s to me so I'll save my money.

early gt550 called for O-5 to O-8. so a few steps larger... I think yeadon_m saw some P-4 in later gt550 may work, or be a little rich on early carbs. I am looking for later carbs 174

Re: GT550 LMNAB Needle Jet

Posted: Thu Apr 03, 2014 9:32 am
by yeadon_m
That part number is correct for 172 P-4 but thats not the same as confirming that is what is on sale. I cannot read the numbers.
Mike