AFTER CARB´S OVERHAUL

[gavicool]

Hello,first of all,thank you very much for your help in the past.
This is the hystoric of this bike to try to get it running properlly...I hope with your help I can get it...
The point is that during the start bike was not able to keep the "idle" (I have to increase it with the nob)and looks that it was running "on 3 carb´s",so I decide to open up the carb´s and check the fuel line circuit.
86´vmax,2 years in garage..so,as I said,first thing is carb´s inspection and gas tanks/filter cleaning/replacement,but in the mean time ,inspection was going deeper..just to try to do a good maintenance because "I´m there already "..this is the list of the working process;
*CDI + Pickup´s -Checked by Carmo Electronics
*Ignition coils ok according to Service book specs
*New spark plugs
*Battery ok(I´m using a car battery to start up )
*KN filter original air filter box
*Stock Vboost
*4/1 Kerker
*Carb´s overhaul/set up ;
-Replacement of Coasting enrichers,jet block´s(blowed/cleaned), jet block´s ruber cubs,vacun piston,orings and cover seals.
-Floats ajusted to 28.5 mm
-150 Mikuni mains
-170PAJ2
-90PAJ1
-Slides drilled
-DJS7 nedles
-DJ S7 springs
-DJS7Air correctors
-A/F- 3 turns out(as a starting point..this maybe should be corrected..wait for your coments...)


After installation of the carbs(without the air filter) and start up, it is running "terrible",I know that I have to synchronize the carbs,but in order to keep the bike running I have to leve the "choke" open...
I do not know if it is possible to made a "previous sychro" with the choke open and move foward.. or ,at this poin ,how to proceed...
I was thinking about the fuel pump(or fuel pump system) as well as the Pressure Sensor,....
How to tune A/F mixture ?

Well, too many things..but I would like your opinion about where to start looking for, just to discard the "obvious"...

Wait for your comments

Thank you for your support.

 

[desert_max]

I will save FM the trouble: I see no mention of your cleaning the pilot jets in this dialogue. Do that, and I suspect your troubles will be over.

 

[02GF74]

86´vmax,2 years in garage..

If your saying it has sat unused in garage for 2 years, then chances are one or more of the pilot jets are block.ed You need to to remove the carbs, seperate into pairs, remove the fuel bowl and then remove the jet block. Underneath one of the two black rubber bungs you will find the pilot jet, remove it by using the biggest screwdriver that will fit in the slot and make sure the hole in the jet is clear.

I had the exact running problem you describe due to blocked jets - I uses a sharpened needle in order to gently prod the crud out of the tiny hole in order to run a piece of copper wire (softer than the brass jet) with nicks so it acts as file, through the hole. Alternatively buy replacement jects.

 

[gavicool]

I will save FM the trouble: I see no mention of your cleaning the pilot jets in this dialogue. Do that, and I suspect your troubles will be over.

Thank you for your repply,Sorry,yes I did remove the jet blocks and clean(carburator cleaning kit needles) and blow the pilot jets ,I do not remove the pilot jets from the jet blocks,is it necessary?

 

[gavicool]

If your saying it has sat unused in garage for 2 years, then chances are one or more of the pilot jets are block.ed You need to to remove the carbs, seperate into pairs, remove the fuel bowl and then remove the jet block. Underneath one of the two black rubber bungs you will find the pilot jet, remove it by using the biggest screwdriver that will fit in the slot and make sure the hole in the jet is clear.

I had the exact running problem you describe due to blocked jets - I uses a sharpened needle in order to gently prod the crud out of the tiny hole in order to run a piece of copper wire (softer than the brass jet) with nicks so it acts as file, through the hole. Alternatively buy replacement jects.

Thank´s for the reply too,but as I coment to "desert",I cleaned then without removed from the jet block.

https://www.ebay.co.uk/p/24029098813

 

[02GF74]

From what I can see, the pilot jets fit into a blind hole and with a drilling off axis to the pilot jet, so I don't think it is easy to tell without precise measurement of depth if the brush has gone through the hole in the pilot jet.

How do you know the holes in the pilots are totally clear? Without very precise measurements of air flow, I don't see how it is possible to tell a partially blocked jet to a clear one by blowing air through them.

The hole is so stupidly small so It does not take much debris to alter its cross section area.

In other words, the best way is to remove the jets and clean the holes out.

Be gentle when using the carb cleaner brushes (I later bought a similar kit) as they are stainless steel so harder then the brass, otherwise you could end up enlarging the holes; hence why I used copper wires, strands taken from a power cable.

Unless someone corrects me, from memory the jet has a tiny hole, about 0.3mm at one end that opens out to a larger hole through the main body. I attach 2 photos. The larger hole is at the end with the screwdriver slot, the tiny one sits in a concave recess, the photo makes the concave recess look like a hole but it's not.

 

[Fire-medic]

OMG, don't bother to get that thing in-focus! Was that from a Hurricane Katrina 'flood bike?' I can see the barnacles from-here!

Here's a pic of a mid-1980's Gold Wing that came-into the shop, I think the license plate was from about 1989. I thought, "now, these are bad!" The odometer showed 34K miles.



Here is the obligatory pair of 'fire-medic pilot jet pictures.'

 

[02GF74]

Below is a diagram of what I believe is the situation in cross-section. The jet block is shown as cross hatched and the pilot jet is coloured grey.
(1) shows the drilling in the block is not inline with the hole in the jet so you will not get a wire passing all the way through both.
(2) shows that the main body of the pilot jet has a bigger diameter hole than the all important tiny fuel metering hole. Pushing a wire into the jet gets past (3) - the end of the jet - but can stop at (2) making you think it has gone all the way through when it hasn't - hence my previous comment about measuring how far the wire has gone.

Thinking about it now, trying to clear the jet by poking a wire through would result in any debris inside the tiny hole being pushed into the jet block and perhaps blocking it hence you have to take the jet out of the block.

When I was trying to clear my pilot jets, some were clogged up solid with a varnish type substance. I used a sharpened needle to chip away at it from both sides and once through, used a copper wire file* to clean it out, a powdery white dust came out when tapping the jet on a surface.

* this home made file is a piece of copper wire (or aluminium MIG wire) that has been crimped very lightly many times with a pair of wire cutters to create a very small needle file.

 

[02GF74]

OMG, don't bother to get that thing in-focus! Was that from a Hurricane Katrina 'flood bike?' I can see the barnacles from-here!

Nope, not my photos - I searched the internet to find photos showing the holes at each end of the jet and these were the best I could find.

During the search I came across a used jet on eBay that clearly was blocked with corrosion worse than the one above for sale for £ 14 - WTF ??? New ones can be gotten for less than half of that.

 

[CaptainKyle]

I see you said you are running the stock air box with K&N filter . Is it the stock type K&N or is it a Morley kit with the big flat K&N ? If you are running the stock type K&N with the regular lid then the air correctors are not needed. Might sound like a stupid question but I have seen people do all kinds of crazy stuff with the carbs on these bikes.

 

[gavicool]

I see you said you are running the stock air box with K&N filter . Is it the stock type K&N or is it a Morley kit with the big flat K&N ? If you are running the stock type K&N with the regular lid then the air correctors are not needed. Might sound like a stupid question but I have seen people do all kinds of crazy stuff with the carbs on these bikes.

It was running with Stock air box ,without the " Y ",but ,as you comment ,I will put back the DJS7 Air pods ..if I can get it running ...

 

[gavicool]

OMG, don't bother to get that thing in-focus! Was that from a Hurricane Katrina 'flood bike?' I can see the barnacles from-here!

Here's a pic of a mid-1980's Gold Wing that came-into the shop, I think the license plate was from about 1989. I thought, "now, these are bad!" The odometer showed 34K miles.

View attachment 75305View attachment 75306

Here is the obligatory pair of 'fire-medic pilot jet pictures.'

View attachment 75307
View attachment 75308

You guys are right,better make sure that the problem is not there...
Other thing that I did not comment,and it is possible that maybe has something to do with the problem ist that during the carb´s overhaul,the jet block gasket that came with the kit was made of rubber,and about 1mm(0.04"),the one that removed was "paper type" more thinner..
I do not know if it is important,but got my attention,during the assembly of the jet block and the needle jet oring..
Other issue is the fuel pump,is there any test can be done to know it´s correct operation?
Thank´s for your comments

 

[gavicool]

Below is a diagram of what I believe is the situation in cross-section. The jet block is shown as cross hatched and the pilot jet is coloured grey.
(1) shows the drilling in the block is not inline with the hole in the jet so you will not get a wire passing all the way through both.
(2) shows that the main body of the pilot jet has a bigger diameter hole than the all important tiny fuel metering hole. Pushing a wire into the jet gets past (3) - the end of the jet - but can stop at (2) making you think it has gone all the way through when it hasn't - hence my previous comment about measuring how far the wire has gone.

Thinking about it now, trying to clear the jet by poking a wire through would result in any debris inside the tiny hole being pushed into the jet block and perhaps blocking it hence you have to take the jet out of the block.

When I was trying to clear my pilot jets, some were clogged up solid with a varnish type substance. I used a sharpened needle to chip away at it from both sides and once through, used a copper wire file* to clean it out, a powdery white dust came out when tapping the jet on a surface.

* this home made file is a piece of copper wire (or aluminium MIG wire) that has been crimped very lightly many times with a pair of wire cutters to create a very small needle file.

View attachment 75314

I know what you mean..and I agre with you,better to remove it.
Is it possible to use a "heat gun" to facilitate the removal of the pilot jet?
Thank you for your comments.

 

[02GF74]

Fuel pump : disconnect hose at carbs and point in a container.

Turn on ignition and pump should start pumping. There probably is data on flow rate litres or gallons per minute so you can check.

Take a look inside the fuel tank, they have a reputation for rusting, if you can see rust/debris at the bottom, then you will need to clean or replace the fuel filter as well as the tank. Remove the filter, let it dry out, tap the filter inlet on a hard surface, if lots of crud comes out, it needs replacing

Re removing the jets. Use the largest screwdriver that fits the slot, maybe a bit of penetrating fluid in first. Heating the block may help release a stubborn jet but usually they are not problematic.

 

[gavicool]

Fuel pump : disconnect hose at carbs and point in a container.

Turn on ignition and pump should start pumping. There probably is data on flow rate litres or gallons per minute so you can check.

Take a look inside the fuel tank, they have a reputation for rusting, if you can see rust/debris at the bottom, then you will need to clean or replace the fuel filter as well as the tank. Remove the filter, let it dry out, tap the filter inlet on a hard surface, if lots of crud comes out, it needs replacing

Re removing the jets. Use the largest screwdriver that fits the slot, maybe a bit of penetrating fluid in first. Heating the block may help release a stubborn jet but usually they are not problematic.

Thank you "02GF74" for your comments,so if I understand ,once I desconet the gas line from the carb´s and turn on the ignition key,should start pumping until I shut off the ignition(recording the time and quantity mean time),isn´t it?
About the jet block gasket that I comment with "Fire-medic";
Other thing that I did not comment,and it is possible that maybe has something to do with the problem ist that during the carb´s overhaul,the jet block gasket that came with the kit was made of rubber,and about 1mm(0.04"),the one that removed was "paper type" more thinner..
What do you think?

 

[02GF74]

Pump flow rate = exactly.
Let's say at 120mph fuel consumption is 20mpg, so that is 6 gallons (UK which are bigger than US gallons) per hour, or 0.45 litres per minute.

Someone on here posted;
I put the output into a bottle and filled a 500ml bottle in 20 seconds.

So that is over 3x what I calculate and should give you something to compare to. (the manual may give a precise spec.)

Re. Gasket thickness, I can't see how that would affect anything, all that happens is the jet block sticks out a bit more, all holes are still aligned.

 

[gavicool]

Pump flow rate = exactly.
Let's say at 120mph fuel consumption is 20mpg, so that is 6 gallons (UK which are bigger than US gallons) per hour, or 0.45 litres per minute.

Someone on here posted;
I put the output into a bottle and filled a 500ml bottle in 20 seconds.

So that is over 3x what I calculate and should give you something to compare to. (the manual may give a precise spec.)

Re. Gasket thickness, I can't see how that would affect anything, all that happens is the jet block sticks out a bit more, all holes are still aligned.

Got it!! thank you.
I will back with more coments after I remove the jet block to make sure everything is "nice and clear"..thank´s once again...

 

[02GF74]

Clean out both jets in the block and main jet. On mine the rubber bungs had hardened so to make it easier to fit them back, a dab of vaseline (petroleum jelly) and pushing them in with a blunt rod down the hole in the centre of them got them in.

Note that ebay is flooded with cheap rebuild kits that includes gaskets, bungs, screws; the jets which are part of the kit apparently are not the best quality.

MAKE SURE YOU NOTE DOWN THE JET numbers in all 4 carbs so you can see if they are the same and if anything was changed from standard, annoyingly I forgot to do this, doh.

Once it kinda idles, the carbs are likely to require synchronising so you will need to invest in a set of gauges.

 

[gavicool]

Clean out both jets in the block and main jet. On mine the rubber bungs had hardened so to make it easier to fit them back, a dab of vaseline (petroleum jelly) and pushing them in with a blunt rod down the hole in the centre of them got them in.

Note that ebay is flooded with cheap rebuild kits that includes gaskets, bungs, screws; the jets which are part of the kit apparently are not the best quality.

MAKE SURE YOU NOTE DOWN THE JET numbers in all 4 carbs so you can see if they are the same and if anything was changed from standard, annoyingly I forgot to do this, doh.

Once it kinda idles, the carbs are likely to require synchronising so you will need to invest in a set of gauges.

About the jet kit´s on sale,I´m with you,there are "great deals" around,but I think ,normally,"you get what you pay for"...
About the jet´s numbers ,you are right I took all the numbers but the pilot jet...
I have the Carbotune Pro,but I think I have to get a closer A/F tune to get an idle more less stable..but first I going to be sure that inside parts of the carb´s are ok,..we all know that Vmax´s carb´s are very "sensitives" to put it in some way...
thank´s for your coments,I will come back with the findings...

 

[gavicool]

Hello,...finally I can take over the bike...
First of all,I would like to tell you Fire-medic,02GF74,Cap-Kyle,...many thank you for your support and "patience" with some of us....
You guys were right!!,3 of 4 pilot jet´s were blocked.....after intense cleaning of the jet block parts and re-assembly back,and some fine tunnining syncro carbs and A/F setting (2 ,5 turns out),everything was running fine at idle...
I ´ll get a ride and check everything...(as soon as I get a new battery...)
Any recomendations about what to test during the ride?
Well,once again thank you very much for your support...