Project "walrus" Yam XS 750

Just shows you can F anything up if you try hard enough.
I made up a manometer today, to balance the carbies on my 750 (manometer worked well - cost $6). The tune was OK, by using a feeler gauge, but I thought the manometer would be better.
Got it balanced and running well. Then I made my mistake. It was a little rich when stating, so I played with the idle screws. 1/4 of a turn at a time but I have managed to bugger it up and now it sounds like yours Ryan!!!!!!!
Just shows if the balance and idle screws are out it will not run. I think I have driven the neighbours mad, so I am giving it a break and will get everything back to standard and start again tomorrow.
Cheers
Tim
 
Hey tim!

I was lucky enough to aquire a Triumph Triple Carb for a reasonable price from the UK.I think I won't bother messing around with the stock carbs.
Will wait for them.
Put some pods on the stock carbs though,2 1/2 turns out...still just fires up cylinder3.
I will however in the meantime investigatr in my other electrical issues.

No lights,rear and front,no idiot lights,no blinkers.

Cleaned up the ground on the frame,fuses are all ok.
Am I missing something?
Are there more grounds on the frame?

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Now I am not an expert, but that cut off plug... that's three phases, plus, ground and a sensing wire. Or in other words unless you have a magic reg/rect-unit in there, that'll have a VERY hard time doing anything. 8)
 
Re: Project "walrus" Yam XS 750

der_nanno said:
Now I am not an expert, but that cut off plug... that's three phases, plus, ground and a sensing wire. Or in other words unless you have a magic reg/rect-unit in there, that'll have a VERY hard time doing anything. 8)
Yes. I wonder why he cut those?
 
Re: Project "walrus" Yam XS 750

This is the plug of the stock reg rec that is supposedly broken.
I didnt take the time yet to remove it from the bottom of the battery box.
The new unit is plugged in (had to use a different modern plug for the new unit).

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... and you should mention that it only took about 3 minutes to find the reason, why it didn't run on all threes... ;D

(Brake-cleaner is pretty awesome as a fault finding tool, don't you think?) 8)
 
Re: Project "walrus" Yam XS 750

der_nanno said:
... and you should mention that it only took about 3 minutes to find the reason, why it didn't run on all threes... ;D

(Brake-cleaner is pretty awesome as a fault finding tool, don't you think?) 8)
Leaky seals? :)
 
Re: Project "walrus" Yam XS 750

Mr.Nanno used brake cleaner to check if his assumption was right that my idle system is clogged...i will check when I'm back on the bike.
Idles are too small too.
Like you stated early data 45's are in the ballpark.guess somebidy messed around with them.

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Ryan Stecken said:
Mr.Nanno used brake cleaner to check if his assumption was right that my idle system is clogged...i will check when I'm back on the bike.
Idles are too small too.
Like you stated early data 45's are in the ballpark.guess somebidy messed around with them.

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It would run anyhow, as long as the jets are clean. I upped my pilots because i run full open exhaust, oval pods, and 896cc with high comp head. My stockish 750 ran perfect with stock pilots.
I would advice you to be 100% sure your existing carbs are clean and flowing what they are supposed to Before you start buying jets
Also verify the jet sizes currently installed first. Life gets easier with some method to the madness
 
Re: Project "walrus" Yam XS 750

Late night carb cleaning.

Jets and passages were clean.
Blow trough all orifices and jets,even the idles were clean.
I have no idea why there 17.5s idles in this carb....
Will swap for 42.5's and see what happens (manual says 42.5 should be stock).
Cylinder 1 float was maladjusted.
Do I measure float height with or without the float bowl gasket on the carb?

Thanks in advance!
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Hi Ryan
The info you have is for the XS750E which had mark II Mikunis
Your bike is a XS750-2D with Mark I and 17.5 pilots were standard with 145 mains.
Cheers
Tim
 

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Re: Project "walrus" Yam XS 750

Thanks tim!

Do I measure the float height from the gasket surface with or without the gasket?

Just investigated more...what is the starter jet?idle and main is installed in the float bowl but where do I find the starter jet in the diagram?
Thank you!
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Re: Project "walrus" Yam XS 750

No gasket when measuring float height, but measure from the surface be gasket sits on to top of the float. I lean the carbs at about a 45* angle, too. Put them on the side so the floats are hanging away from the needle valve (not touching) then rotate them back until they are just barely touching the spring loaded pushrod at the top...to make sure the weight of floats themselves are not skewing your measurement


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Re: Project "walrus" Yam XS 750

Hi Ryan
Bloody repair manuals, you can't live without then, but sometimes they send you crazy!
Apart from that listing, I cannot find any other reference. Now I have never worked on a BS34 series I, but the only other "jet" I know in the starter circuit is the air pilot jet. It is located in the air inlet area. On the series II there is a jet that is removable. If your series I also have a removable jet in the air inlet, I am guessing that is the starter jet????
Hope there is someone else who knows exactly online.
Cheers
Tim

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Re: Project "walrus" Yam XS 750

Looks like I might have found the issue...
Had a telephone call yesterday with the a german triples club member.
The starter jet is pressed into tje float bowl.
There is a brass tube running into that tiny orifice in the float bowl.
When I cleaned the carbs I forgot the clean that orifice thoroughly (the float bowl was filled with gummed up gas).
This is the reservoir for starting gasoline.
The tiny bore ends in a small hole which tends to gook up.
I currently soak it in carb cleaner...lets see...
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Got to love the internet and modern communications.
One question - I thought you had bought a new set of Triumph Makunis? Why bother with these BS34 series I???
Good luck
Tim
 
XS750AU said:
Got yo love the internet and modern communications.
One question - I thought you had bought a new set of Triumph Makunis? Why bother with these BS34 series I???
Good luck
Tim

The "new "Mikunis didnt arrive yet...it takes 2 weeks (!!) for stuff to arrive from the UK going to austria.
Since I have 2 Xs 750´s (the one i´m working on right now wills stay stock) I have to deal with that carb anyways :)
 
Ryan Stecken said:
Late night carb cleaning.

Jets and passages were clean.
Blow trough all orifices and jets,even the idles were clean.
I have no idea why there 17.5s idles in this carb....
Will swap for 42.5's and see what happens (manual says 42.5 should be stock).
Cylinder 1 float was maladjusted.
Do I measure float height with or without the float bowl gasket on the carb?

Thanks in advance!
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First you need to verify the jetting for these specific carbs. Mk1's may or may not have a completely different fuel delivery system compared to mk2's. I dont know, i never read anything about them and only ever worked on mk2 carbs. 17.5 may well be the correct stock size.
Soaking may not suffice in cleaningg the fuel passage, probe it with a wire as well.
You measure float height without gasket.
And as i said in pm, those triumph mikunis have a reputation for rapid needle and needle jet wear, that is why they swapped to keihins on later models.
I would not buy them as they are fundamentally flawed.
 
Re: Project "walrus" Yam XS 750

Thanks data!
Checked and doublechecked,17.5'd are the right idles for the MK1 carbs.
I will blow them trough and check with a wire.
Which bike models had these keihin carbs?when I receive the carbs i will have look and probably send them back.

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You have to at least stick them on and see what happens!!!
If they slip straight on, it would be too tempting for me to not try them.
 
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