choke problems with restrictive pods

[beaverbeliever]

I'm new to this site mainly because I've got the kid brother bike (79 xs750) but I've spent many hours looking through this site for various subjects including the revelation that some aftermarket pods were restricting air flow. I'm curious to see if any of you who had the restrive pods (the ones with the lip) saw any starting or choke problems? With the pods on mine it would also stumble around 6000 but it doesn't like full choke even with the temps are in the 40's or lower. It will need to be without choke to get it to fire then I have to quickly move it to full choke to get it to run but the rpms stay low at 1500 rpm and don't climb. It starts to improve a little at half choke but the plugs are very very black. Just curious what you guys have seen.

[TopCatGr58]

Hey Beave,

Black sooty plugs are a sign of too rich, but doubt it's all from the pod filters. Have you done a carb cleaning recently, put in any new parts, like pilot jets. Some K&L kits were known to use different sized jets causing overly rich conditions for many folks. Also, float height can affect it as well.

I've not seen/heard about anybody having problems with their choke/fuel enricheners being too rich due to the pod filters restrictiveness.
T.C.

[beaverbeliever]

I've cleaned the carbs pretty thoroughly and experimented with different size pilot jets but I'm back to stock. Looking at the way the pods attach to the carbs air must flow in 90 degrees from the path into the carbs. It must turn quickly and then flow into the carbs and then make a quick bend to flow into the inlet ports on the backside of the carbs with the pods on. As I understand it the air jet supplies the pilot jet with air and if it isn't getting a good flow then I'm pulling in a very rich mixture from the pilot circuit as well as the choke circuit.

I'm doing some minor valve adjustments and awaiting shims at the moment so I won't be able to do a test without the filters for a few days.

[egleaves]

I have the pods you speak of, but I have never had any choke or idle problems caused by them. I believe the real problem is the air flow restriction caused by that lip when running high RPM.

[beaverbeliever]

I pulled the pods off tonight and tried to start it and it started on full choke but remained at around 1500 rpm. The high idle at choke never appeared. Not sure were to go next in trying to find this problem.

[dbeardslee]

I was having problems with my choke not working properly about 2 months ago. Wound up being plugged filters on the carb vent tubes. Took the filters off and it worked fine. My $.02.

[TopCatGr58]

Hey Beaver,

Okay, you actually have to start it WITHOUT the choke, and then quickly pull the choke out once it hits!?!?

This now sounds like the choke circuit is partially clogged, hence probably why it never rises in rpm as it warms up!

There is a small jet in the float bowl that is easily clogged with crud, and the choke/fuel enrichener circuit gets fed thru that jet/hole, but if it's clogged, then fuel can't get up thru the pipe to the choke circuit, so no extra fuel!!!

You can use a fine wire to poke thru the jet to unclog it along with liberal squirts of spray carb cleaner, just watch your eyes!!
T.C.

[beaverbeliever]

Thanks topcat.. I've had these apart and sprayed carb cleaner through them and it sprays on through. I've also taken them completely apart and boiled them in lemon juice. As dark as the plugs are when it chugs away under full choke its getting plenty of fuel. After 2 minutes or so of half choke it also starts climbing very slowly up to 3000 but neither full or half jump quickly up to full high idle.

[Ivan]

I've also taken them completely apart and boiled them in lemon juice.

This witch doctor has not seen that mojo before. Please elaborate.

[beaverbeliever]

I found over and over on different sites a recommendation to boil carbs in lemon juice as the acid in the juice helps to break down the built up fuel varnish and its easier on rubber pieces like the butterfly shaft seals. After a 15 minute boil I then took the air compressor to all the ports, holes tubes I could find and had air come out on the other side of everyone. I have my doughts that I have an obstruction but maybe I've missed something.

I'm really at a loss of what to try next. Either not enough air is coming in at choke or too much fuel. I've tried the air/fuel mixture screws at stock 2 1/4, and turned them in down to 2 and 1 3/4 with not much of a difference. I've got the fuel level lowered so its at the lean end of the stock settings.

As far as I can tell at choke the choke plunger opens up the circuit to flow fuel from the long tube into the bowl. Air is brought in through an opening below the diaphragm which is fed by the curved air intake port. There would also be some fuel coming in from the fuel mixture screws as well.

I've also been putting in fresh spark plugs as I keep trying this. I probably have 20 plugs sitting on the work bench at this point.

What else should I try?

[DiverRay]

Do you still have the metal floats?? If so, try setting them about 1mm off from "stock". If the book calls for 27mm, try 28mm. If this helps a little, adjust a little bit more, going to 28.5mm. I've found that the older floats do not float quite like they did when new, and adjusting the level just a little bit will get the cards back to the proper running.

[Ivan]

If your plugs are merely fuel fouled, you can burn them clean with a propane torch. Just get them hot enough to burn the soot off, and they will work well again.

[beaverbeliever]

I've thought about lowering the floats a little more at a time and see what happens. If I did turn the fuel mixture screws way in under full choke I would get the rpm to raise but as soon as I take the choke off it won't run because there isn't enough fuel. Makes me wonder if I didn't get the pilot air jet or main air jet (whichever is pressed in) clean. I'll take a closer look at that one tonight. Not sure where that circuit runs and where I can blow air backwards through from.

[tarzan]

Beaverbeliever,can you put what year and model bike you have in your signature?I didnt thoroughly read through this whole post,just skimmed through it, but I didnt see what you set your floats to.You do know the earlier carbs have a lower setting right?If they are set too high it will flood.Too low and it will starve.Also like TC said the little tiny jets in the circuit in the side of the bowls may be plugged.

[dbeardslee]

Carefull with compressed air while the bowls are attached. If you have brass floats the increased air pressure inside the bowl can squeeze your floats. Bowls off only. That having been said, a shot down the vent lines might be in order.