GSX250E bogging down after a mile - dirty petrol ?

[ukjules]

1980 GSX250E bogging down intermittently:

I took my bike out today and it seems to bog down and splutter and go on one cylinder
and can only get home with great difficulty revving it very high sometimes on one cylinder. This now is reliably what
will happen if I ever take it out. It seems to happen even within a mile out.

I am convinced the plugs are ok, Timing and coils I am sure are ok and the battery is charged.
It feels like a petrol issue.

Now the tank was a mess inside and I cleaned it with acid etc years ago and it has worked for a few years fine.
-perhaps this is the issue. when left crud settles and somehow gets through 2 filters ?

Now I remove the tank. Swilled it out and yes I have found small particles I catch when emptying it.
I am yet to clean the fuel tap or take it off
I remove the carbs , and yes some jets are blocked. I clean and put it all back.

I run the bike from a external petrol tank and it fires up fine. sounds great stationary ticking over and revving.
I put the tank back and take it for a test run and again it bogs down and splutters within a few miles.

Now I have the tank filter and the inline fuel filter. I even changed the inline fuel filter but the same issue.
Now before I clean tank , petrol tap and carbs I have to know what people think ?

Q) how on earth can dirt get through a) the tank filter and b) the inline petrol pipe filter I put on ?
How on earth is this possible ?

I am prepared to line the tank (or do my acid tank internal clean again), but what’s think ?

 

[zed1015]

Is it the same cylinder each time.
If so it could be a coil failing or the ignitor when hot .
To rule out or find the faulty coil, swap them round and if the problem switches to the other cylinder it's the coil.
If the problem stays on the other cylinder it could be the ignitor .

 

[ukjules]

?k. It is hard to tell which cylinder but good point.
I have spare coils too. I Will add them to my tests. and report.

- don't forget last check when carbs stripped yesterday a few jets had blocked holes. when I say blocked I could not see through them and a quick blow solved it so that could be a red herring.
(I cleaned them properly after)

a seemingly dirty tank (when i swilled out ways had some particles in). and it has 2 filters on it.

that is why I think fuel.

but I agree coil is so so what it look like

 

[Cipher]

Two filters eh? Remove the filter you added and don't be surprised that rust and other particles can get through a filter. If things could not get through it would be called a plug not a filter. Also whatever goop suzuki uses to affix the petcock filter get old and leaks over time in my experience meaning its not really a filter at all.
My bowls always have a bit of fine debris finer than sand and occasionally largish chunky looking like rust. I drain the bowls onto a piece of clean paper towel whenever I can remember once in a blue moon.

Its also nigh onto impossible to get all the crap out of a tank and even though you get close more is created as rust never sleeps.

Another problem may be tiny dome filters over the float needle valve seats if so equipped. Back flushing is advised over removal as these are a GDPITA to remove without damage.

What engine and road speed does the bog occur at? is it in highest rpm prior to shift to next gear?

 

[zuluwiz]

I had a problem last fall somewhat similar to your, the Ratzuki would fire up just fine, but out on the road i lost power. I finally figured out the battery was not charging. a new battery and it's fine. You say your battery is charged, thats good. One less thing to worry about. Another possibility would be a choked vent in the gas cap. That might cause the problem you describe. Or even a kink in the fuel line.

 

[Big T]

I see the initial post

 

[ukjules]

Thanks guys for info.

For some reason I read somewhere in one article (not on this site ) that on old bikes this chap would not run them without a secondary filter. I'll ignor that on my bikes now.

fuel cap venting. any tips on how to clear out a fuel cap? carb cleaner , Air line?

gloop to affix petcock filter:

A good point. I have never put any sealant when refitting. Any suggestions ?

the bogging down happens all over the rev range it seems. from low to.medium. it is def not set in one area. I never get to max revs .

Battery - Now this is a good point. The battery I did Park and bought another. I am convinced it worked fine with the new one but j thought I'd try the old one again after a charge. timescales of months here.

it seemed to work but this is happening with that old battery. the new battery is in my GS550E...... and is fine.

fuel line kink. Will check .

I'll work through these points. and report . thanks .

 

[Cipher]

You can disassemble the squarish gas caps and clean them. Not sure about the round ones. Mine plugged once many years ago and I did this as I was scared to melt something with carb cleaner.
A quick, dirty, and no doubt needlessly dangerous way to check the caps not contributing is to run with low gas no cap. Not for the faint of heart.

No idea what they used to glue in the filters and Id be loathe to try anything that might shift over time and enter the carbs.

If your battery is fully charged and alows the starter to crank fast and the bike to start easily then short of using a volt meter with a large bright display while driving the only way to see if its a fatal charging issue is to runt he bike till it dies and the battery is flat.

AS to coils I have had one fail iirc but that only manifested in rain and then largely due to the connection wiring becoming frayed over time.

I wrote this in notepad as the site is acting like a bastard today

 

[zed1015]

What I mean is, zed1015 is post number 1 in this thread. He appears to be addressing a question asked by whom? The thread title ""GSX250E bogging down after a mile - dirty petrol ?" was posed by zed1015? He's answering his own question?

No Mate.
My post is the 2nd .

The first was posted by UKJULES.

Here's the first post copied and pasted if you still can't see it..

1980 GSX250E bogging down intermittently:

I took my bike out today and it seems to bog down and splutter and go on one cylinder
and can only get home with great difficulty revving it very high sometimes on one cylinder. This now is reliably what
will happen if I ever take it out. It seems to happen even within a mile out.

I am convinced the plugs are ok, Timing and coils I am sure are ok and the battery is charged.
It feels like a petrol issue.

Now the tank was a mess inside and I cleaned it with acid etc years ago and it has worked for a few years fine.
-perhaps this is the issue. when left crud settles and somehow gets through 2 filters ?

Now I remove the tank. Swilled it out and yes I have found small particles I catch when emptying it.
I am yet to clean the fuel tap or take it off
I remove the carbs , and yes some jets are blocked. I clean and put it all back.

I run the bike from a external petrol tank and it fires up fine. sounds great stationary ticking over and revving.
I put the tank back and take it for a test run and again it bogs down and splutters within a few miles.

Now I have the tank filter and the inline fuel filter. I even changed the inline fuel filter but the same issue.
Now before I clean tank , petrol tap and carbs I have to know what people think ?

Q) how on earth can dirt get through a) the tank filter and b) the inline petrol pipe filter I put on ?
How on earth is this possible ?

I am prepared to line the tank (or do my acid tank internal clean again), but what’s think ?

 

[ukjules]

no idea what some are talking about. j posted this subject re bogging down.


Work today - total failure still.

Charging test:

Using my new battery .

on bike ignition off - 12.7v

ignition on - 12 36

tickover- 12.41v

4k revs - 12.64
regulater issue ? as voltage should increase to over 13 to 14v ?

Road test:

fuel cap off
New battery
still bogs down intermittently

Road test 2:
filter off , new fuel line
still bogs down intermittently

note:

looking through my notes a few years ago I had an issue similar ... pickup connector box faulty. renewed and issue went away.

I will look at this.
can't find my spare coils so not tested bar :

lh primary 4.2ohms
secondary 11000 without plug

rh primary 4.2ohms
secondary 10009 without plug


however I'll add a pic of a test I did a while ago on coils. seem to suggest a poss problem.

 

[ukjules]

Previous analysis on these coils

 

[Cipher]

Intermittent the diagnosticians word for hell

A fuel supply issue might vary with engine speed or exist due to flow restriction but should be consistent. The one thing I can think of would be a leaking petcock diaphaghm or a collapsing petcock vacuum line.

I would trace the ignition and test for shorts to ground and also the plug caps as they act oddly when they are at end of service life.

 

[ukjules]

I am sure petcock and vac line ok. no kinks of fuel line.

I am concerned with the:
-Regulater - doesnt seem to charge the battery right ? 4k revs on 12.6v
this is not right
-pickup cable and connector
-coils. while a static test shows they seem ok - but my attachment shows a difference. thing is i dont know what that means

 

[ukjules]

Update:
Status - inline fuel filter removed .
carbs not cleaned out
not tried my spare coils yet
regulater doesn't seem to charge over 12.9v even increasing revs.

Today I checked the pickup cable, which according to my notes caused a similar issue 3 yes ago. That time I put on a new block connector for the 4 wires.
- on checking 2 wires pulled out without any force Clearly a loose connection.

Started first time snd felt smooth. However a mild stutter but it has to be said it is better. so this pickup lead was at least some of the issue.

perhaps a run might help ?

 

[ukjules]

update:
- inline fuel filter off
- no links
- rewired pick up leads

within a mile is was doing same , bogging down.

went on 1 cylinder. pull rh plug and that's te one that has the issue.
so
plug
ht lead
rh coil

 

[zed1015]

update:
- inline fuel filter off
- no links
- rewired pick up leads

within a mile is was doing same , bogging down.

went on 1 cylinder. pull rh plug and that's te one that has the issue.
so
plug
ht lead
rh coil

So the next step is to swap the coils and if the other cylinder fails it's likely the coil and if the problem remains on the same one it's the pickup or ignitor etc for that cylinder.

 

[ukjules]

Update:
pickup leads re wired
inline filter off
no kinks in fuel line

next:
as suggested coils.
- I found my spare set of coils. these have the ht lead hard wired into them as do originals. I went and put them directly in.
(note to swap coils over is a but hard as block connectors different so can't get wrong.)

- different set of coils
- different ht leads
- same plugs (never touched these )

2m run and no issues. Need a longer run but I hold my breath.

New coil stats ;
both
secondary 4.4 ohms
primary 11000 ohms

 

[ukjules]

Long 15m run and no issues.

so I think it was either coil or ht lead.
and possibly not helped by the poor
wiring on the pickup connector.

I don't think fuel had anything to do with
it ......

 

[ukjules]

and .....
the bike starts immediately . pre doing this work with coils etc it was hard to start. now at the flick of the switch it starts. never known that with this bike .

but of course never swapped coils

 

[ukjules]

It went again. 1.5m out and had to push it back a mile.
bogging down, and then elecs just stopped. now ig light but no starter motor.

so I have achieved nothing. I just cannot get to where this is coming from