Carb Rebuild Complete - Dies on throttle

[oohsam]

Thanks guys, that is some amazing information right there. Exactly what I was after.
CR480 - Top info there mate. I'll do just that..

Pete...where did you get your jets from? Looking for an Aussie supplier.

Cheers

[oohsam]

Oh one more thing, is it common to replace all 3 jets ? ( Main Jet, Pilot Jet, Air jet) ?
Or is normally just the Main Jet ?

also, how does one convert the numbers from dynojet to the minkuni numbers?
Example

Stage 3 kit comes with :

4 Main Jet DJ114
4 Main Jet DJ118
4 Main Jet DJ165
4 Main Jet DJ170
4 Fuel Needle DNO405
4 Adjusting Washer DW0001
4 E-clips DE0001
4 Main Air Jets DCO301
1 Slide Drill DD #7/64
1 Plug Drill DD #5/32
1 Screw DS000

Do I need all those??

Thanks for help.

[koolaid_kid]

With just pods you will use the smaller mains and all the other parts. You can probably adjust the factory Pilot Jets to suit. If you need them you have to buy them from a dealer or Z1Enterprises (my choice). They are around $2 each.

[oohsam]

Ok I'm still confused.

The Stage 3 Kit comes with stage 1 components too...thats why there are 2 small jets and 2 large jets.

So I'm running pods and an exhaust, so I'm assuming I'll need to change the Main jets from what I currently have (stock 115) to 122.5, which is 3 sizes up ? (surely 170 is too large?)

I'm currently running a #40 pilot jet (i also have a #45 that came with my rebuild kit) does that need to be changed too?

With the air jet, does that need to be changed at all ?

I'm way out of my depth here guys, have no idea what needs to go up/down in order to compensate pods and exhaust.
So many threads where so many people have tried different things, but there has been nothing conclusive or rock solid with a "winning" solution!

[cowboyup3371]

Ok I'm still confused.

I'm way out of my depth here guys, have no idea what needs to go up/down in order to compensate pods and exhaust.
So many threads where so many people have tried different things, but there has been nothing conclusive or rock solid with a "winning" solution!

I still have the stock setup on my bike so I can't answer how to fix yours. However, this last statement of yours is why so many people on here tell everyone else to start with a stock set up first to ensure the bike runs correctly. THEN, and only then, should anyone start to change things from there as there just isn't a right answer. You have to adjust things based on your bike, what you intend to do, and it takes a whole lot of testing to get it right.

Good luck. I hope you can figure it out without having too many headaches.

[Super]

OK, I'm going to throw another monkey wrench into the conversation. My son's little '79 GS425 was switched to pods (Emgo) but kept the stock exhaust. We had bought these long before we realized the issues people have with the Emgo pods.

So on our first shot at using these, we decided to try and adjust the amount of air (too much) going into the intake. We did this by attaching some thin foam material with zip ties covering about 70% of the outside of the pods. Amazingly, it worked!! He's ridden the bike all last summer with no issues at all. Now I'm not advocating this as a solution, but it might be worth 15 minutes of fiddling just to see.

PS...the earlier advice offered by others before me is the right way to go. Just take your time as it's not that hard...just frustrating some times.

[cr480]

Ok I'm still confused.

The Stage 3 Kit comes with stage 1 components too...thats why there are 2 small jets and 2 large jets.

So I'm running pods and an exhaust, so I'm assuming I'll need to change the Main jets from what I currently have (stock 115) to 122.5, which is 3 sizes up ? (surely 170 is too large?)

I'm currently running a #40 pilot jet (i also have a #45 that came with my rebuild kit) does that need to be changed too?

With the air jet, does that need to be changed at all ?

I'm way out of my depth here guys, have no idea what needs to go up/down in order to compensate pods and exhaust.
So many threads where so many people have tried different things, but there has been nothing conclusive or rock solid with a "winning" solution!

OK. The kit for your bike does show both stage 1 and stage 3 jets. With pods and performance exhaust you have a stage 3 setup. Here is what it showed for your 83 gs1100

4 Main Jet DJ132

4 Main Jet DJ138
You will need a set of 138 and a set one size up = 140 main jets to get started. I would install the 140 jets first as they are most likely to run well with your setup. Leave the primary jets alone for now. Start by only changing the main jets and setting the mixture screws. Once installed and running, Test bike. then adjust the mixture screws as I explianed earlier, test bike. It is important to make only one change at a time when tuning carbs, make the change and test the bike's performance after each change. If you do not achieve better performance after making an adjustment, go back to where you where before the adjustment. If it won't idle at all after you have made the mixture screw adjustments but runs well when on the throttle you may want to go the larger primary jet but I doubt you will have to. Once you have a decent running bike try raising the needles up one slot and test the bike, if it pulls harder, try going up one more and test bike, if the bike is slower go back the other way. Do this until you achieve the most powerful settings. If the bike bogs while on throttle after changing the main jets, test the jetting by reading the plugs as i explained earlier, Black and sooty = too large of a main jet.
Bone white = too small of a main jet Light brown + you nailed it! Move up or down in jet sizes 1 size at a time as needed. Those 140's will get you very close but don't be surpised if your bike wants 142's or even larger as pods and performance exhaust is the most free flowing setup for the street. it will depend on your engines overall condition wether it needs more or less fuel from your main jets.

[rustybronco]

Ok I'm still confused.


I'm way out of my depth here guys, have no idea what needs to go up/down in order to compensate pods and exhaust.
So many threads where so many people have tried different things, but there has been nothing conclusive or rock solid with a "winning" solution!

You might be to get the main jetting close, you may even have adjustable needles. what you don't have is the correct needle taper and don't know what size hole to drill in the slides.

I think you need to revisit post #5.

[cr480]

OK, I'm going to throw another monkey wrench into the conversation. My son's little '79 GS425 was switched to pods (Emgo) but kept the stock exhaust. We had bought these long before we realized the issues people have with the Emgo pods.

So on our first shot at using these, we decided to try and adjust the amount of air (too much) going into the intake. We did this by attaching some thin foam material with zip ties covering about 70% of the outside of the pods. Amazingly, it worked!! He's ridden the bike all last summer with no issues at all. Now I'm not advocating this as a solution, but it might be worth 15 minutes of fiddling just to see.

PS...the earlier advice offered by others before me is the right way to go. Just take your time as it's not that hard...just frustrating some times.

It worked because you restricted the airflow going into your carbs in a similar amount that the stock air box had before it was removed. this will enrichen the fuel mixture and cancel out the lean condition created by installing the free flowing pod filters. less air more fuel = richer mixture
More air less fuel = Lean mixture all engines require a balanced and proportionate fuel - air mixture to run properly and stay cool.

[cr480]

You might be to get the main jetting close, you may even have adjustable needles. what you don't have is the correct needle taper and don't know what size hole to drill in the slides.

I think you need to revisit post #5.

The needle taper point is interesting to me. I have done many rejets and have used thier kits many times with decent results. As time went on I stopped using the kits and rejetted on my own. I achieved better results on my own and saved many dollars doing so. If you look at thier kits. they use the same needles wether you are running pods or not. I have never been able to actually feel a difference between the two. If the needles truly need to be optimized for pod filters I doubt that they would be optimal for a Stage 1 kit -stock airbox setup with an aftermarket filter. If you send your bike to a shop for performance jetting they are not going to install a kit. They will almost always avoid the extra cost and rejet manually. Proper jetting with stock needles will not make bike run lean. I fail to see the major compromise here between the 2. Can someone help clear this up for me? Much appreciated.

[Steve]

Example

Stage 3 kit comes with :

4 Main Jet DJ114
4 Main Jet DJ118
4 Main Jet DJ165
4 Main Jet DJ170
4 Fuel Needle DNO405
4 Adjusting Washer DW0001
4 E-clips DE0001
4 Main Air Jets DCO301
1 Slide Drill DD #7/64
1 Plug Drill DD #5/32
1 Screw DS000

Just so you know: the 165s and 170s are NOT "main jets".

They are the "pilot air jets" that go into the carb intake throat at about the 8 o'clock position.


Referring back to one of your earlier posts about the bike stalling when throttle was applied: did you have any filters on at the time?
As you have seen, the jetting needs to be changed for the type of filter that you have. If you have NO filter on the intake of the carbs, the bike WILL stall, unless you have the carbs jetted for that situation.

Regarding ct480's post about lean jetting running hotter. VERY TRUE, but for synchronizing the carbs, you are not getting into the main jet, so your jetting is still controlled by the PILOT FUEL JET and the PILOT AIR JET making a mixture, which is then controlled by the IDLE MIXTURE ADJUSTMENT SCREW. Usually, those jets are left stock, although some DJ kits have a "correction sleeve" that is inserted into the air jet to richen up the pilot mixture a bit.

When you did your "full rebuild and carb teardown", did you replace the intake boots between the carbs and the engine? If you have a bit of an air leak there, it might account for your "hanging idle". I was going to do the standard suggestion of changing your intake o-rings, but your bike does not have them.

.

[rustybronco]

I for one cannot clear this up for you. I don't have the ability to bench flow a set of carbs.

I do know the taper is different between the stock needles and the ones in the dyno jet.

when jetting for pods, what have 'you' done to increase the fuel supplied during part throttle operation? did you change spring tension on the slides?

[7981GS]

If you have NO filter on the intake of the carbs, the bike WILL stall, unless you have the carbs jetted for that situation.

Really? What am I doing wrong???

http://www.youtube.com/watch?v=TcMWTHTkts4

Daniel

[gearhead13]

You are running a #40 pilot?? theres your problem. Dont assume that your rebuild kits come with proper sized jets
Put in the #45's and I bet your stalling goes away
EDIT: I looked it up and the service manual says a #40 pilot, but that is for a STOCK bike with airbox, a #45 would be a better choice.

[pete]

I'm getting my jets from www.iwt.com.au in SA. $8.50 each for my pilots and mains and I just give him a call and get him to express post so I get it the next day. $9 is what he charges for express post.

He has a full price list on there somewhere so you should be able to see needle prices as well I would imagine.