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The 2-Stroke Garage => Turning Wrenches => Topic started by: Milan on June 09, 2022, 09:08:26 AM

Title: SOLVED = RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 09, 2022, 09:08:26 AM
Got the tank on i bought thru the Sale section.
Got the Electrical sorted out.

carbs cleaned.
Put gas in.

Only right side fired right up.
Switched plugs, same thing, only right side.

I then switched spark plug leads, and nothing = is that normal as the timing per cylinder may be opposite?



So, anyone have a short list of order to what to check, and values.
I also have a 250 here I can compare to, and swap parts just to get running.



Title: Re: RD350 Running on 1 Cylinder : Advice
Post by: Striker1423 on June 09, 2022, 10:04:26 AM
both sides are timed separately, so, just swapping the leads means the plug will fire at bottom dead center instead of top.

To check the coil functions, swap the COIL wires left and right. That doesn't affect timing. If the bike starts running on left side then you found your culprit in the coil. Also, you can simply lay the plug across the head and see if it sparks as you kick it over.
Title: Re: RD350 Running on 1 Cylinder : Advice
Post by: m in sc on June 09, 2022, 10:16:09 AM
check connections at points. also make sure left side crankcase isnt full of fuel. take plug out, run on right cyl only. see if a shitload of fuel pumps out of left cyl. if so, thats prob the issue. let air out, fit new plug, try again.

if not that, then onto electrical.
Title: Re: RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 09, 2022, 10:26:05 AM
I was thinking that timing thing as stated above, and that they were opposite.

When I took left plug out it was not soaked.
So do not think its flooded

I will try the coil swap tonite.

Thanks all.

M
Title: Re: RD350 Running on 1 Cylinder : Advice
Post by: m in sc on June 09, 2022, 10:51:20 AM
when you kick it over with the plug out does it spark? if so.... look at carb.
Title: Re: RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 09, 2022, 11:00:01 AM
I will try the spark thing first.

Hard to convince my 14 year old daughter to hold the spark plug while I kick it over.

She asks why?
I say to see if it sparks.

The she runs away.
:dawg:
Title: Re: RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 09, 2022, 11:03:45 AM
So if the coil ends up being bad:
Find a Stock one, or is there a better aftermarket choice?

M
Title: Re: RD350 Running on 1 Cylinder : Advice
Post by: pdxjim on June 09, 2022, 11:25:11 AM
Quote from: Milan on June 09, 2022, 11:03:45 AM
So if the coil ends up being bad:
Find a Stock one, or is there a better aftermarket choice?

M

Dyna mini coil is a great choice and about $100 on ebay.  Lots of cheaper options tho.
Title: Re: RD350 Running on 1 Cylinder : Advice
Post by: m in sc on June 09, 2022, 11:42:59 AM
1st gen sv650 coil. pretty much a bolt in.


https://www.2strokeworld.net/forum/index.php?topic=4576.msg38688#msg38688
Title: Re: RD350 Running on 1 Cylinder : Advice
Post by: 2steve on June 09, 2022, 04:09:34 PM
Or stock ones from Economy Cycle.
Been there, done that.
Title: Re: RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 09, 2022, 05:53:18 PM
Troubleshooting

Primary coil =
4.3 & 4.4

Secondary =
8.4 & 8.6  no cap

Secondary with cap =
50 & 0.

2 different leads.
1 has straight wire that pushen into hole in cap.
That one gave 0.

Other cap is twist on type & gave 50.

So pysh type not makinge contact

Title: Re: RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 09, 2022, 06:07:19 PM
So I bent & burred the straight wire a little.
Put back in, and now I hava 8.6 at the cap.
The orher twist one still has over 50
Title: Re: RD350 Running on 1 Cylinder : Advice
Post by: m in sc on June 09, 2022, 09:36:05 PM
replace the caps. they should all screw in. like said, caps and wires minimally.

Title: Re: RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 10, 2022, 09:14:20 AM
One of the leads had a solid wire in it?
So cannot screw in a cap.

I ordered a set from HVC
Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 11, 2022, 02:08:51 PM
Put the 250 coils & wires in the 350.
Started on 1 same cylinder again.

Took plug out. Was wet.

Started bike and getting spark.
Let air out.
Put plug back in.

Started on 1 cylinder again.

Such thing as a weak spark?
Nit being enough to ignite?

M
Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: m in sc on June 11, 2022, 03:05:55 PM
did you ever check for spark w the plug pulled out?
Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 11, 2022, 03:35:02 PM
Yes.
Sparks like crazy when laid on case while bike running on other cylinder.

Is there a way to measure this?
Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: Brad-Man on June 11, 2022, 03:36:30 PM
What is your battery voltage?
Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 11, 2022, 11:09:16 PM
Took the Battery out of the 250.
Put in.

Bike starts. One cylinder.
One kick.

Gracias

M
Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: m in sc on June 11, 2022, 11:26:04 PM
probably a carb issue then.
Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: 2t Fan on June 12, 2022, 03:11:45 AM
stock points ignition ? engine having good compression ?
Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 12, 2022, 11:48:44 AM
I believe its stock ignition & points.

Had borh carbs out & cleaned them.

Don't have a compression tester.
But even if low it still should start on that cylinder?

Is there such a thing as low spark?

Took other plug out.
Kicked bike over.
Get a nice blue spark

Other cylinder plug just gets a little spark.

So points or condensor?
Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: m in sc on June 12, 2022, 02:11:09 PM
points are just a mechanical switch. if the condesor goes bad it will spark a LOT at the points when running. what is the voltage at the brown wires at the coil with the key on? I dont care if its a brand new battery.

compression shouldnt matter to get it to idle unless theres a hole in the piston.

make sure the wring at the points is isolated correctly as well. like this:

(https://www.2strokeworld.net/wp-content/uploads/general-tech/ignitions/points-wiring-layout-insulator.jpg)

also make sure the gap is set to .3-.4mm.

Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 12, 2022, 03:14:28 PM
About 12 volts at brown wire, that is common to both coils.

Orange wire on left side has continuity from coil to points.
Points are closing.

So where does the power come from prior to the points that makes the pulse?
Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: m in sc on June 12, 2022, 03:35:30 PM
the points collapse the field,  that 'sends' the power to the plugs. so its from the battery. either your crankcase is full of fuel, exhaust is clogged (doubful) or your carbs need to be looked at again.

Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 12, 2022, 03:56:03 PM
Not getting spark on left side
Spark produced using orange wire from point when contacts open & close.
Right?

Found this

Too wide a point gap decreases the dwell angle. This does not give the coil sufficient time to charge, resulting in a weak spark.

So time to order the tool & check the gap

M
Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: m in sc on June 13, 2022, 11:13:42 AM
just use a feeler gauge and set gap. 

you said:

'Yes.
Sparks like crazy when laid on case while bike running on other cylinder.

Is there a way to measure this?'

now there's not.  this makes no sense.

Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 13, 2022, 11:17:19 AM
Yes.

Confuses me too.

It was sparking when I first looked at it.

Now it is very weak, or non existent.

I will work on it again tonite.

M
Title: Re: Update RD350 Running on 1 Cylinder : Advice
Post by: m in sc on June 13, 2022, 11:23:59 AM
CHARGE YOUR BATTERY AS WELL, and look at condition of all wires and connectors related.  I chased a bad points-to-coil wire on my T500 for a few weeks, and it was intermittent.  repaired it, then put on a cdi anyway. lol.



Title: Re: SOLVED = RD350 Running on 1 Cylinder : Advice
Post by: Milan on June 14, 2022, 07:40:32 PM
Looks like it was a bad condenser.
Swaped leads & got spark.

Put RD250 one on, & both spark.

Must have had a short to ground on that side.
( single condeser, dual leads )
Title: Re: SOLVED = RD350 Running on 1 Cylinder : Advice
Post by: Brad-Man on June 15, 2022, 02:08:07 AM
Good news!
Title: Re: SOLVED = RD350 Running on 1 Cylinder : Advice
Post by: m in sc on June 15, 2022, 10:11:22 AM
glad you found it. changing the 40+ year old ign components is one of the 1st things i do on a 'new' bike.
Title: Re: SOLVED = RD350 Running on 1 Cylinder : Advice
Post by: patastinky on June 27, 2022, 09:26:59 PM
Quote from: m in sc on June 15, 2022, 10:11:22 AM
glad you found it. changing the 40+ year old ign components is one of the 1st things i do on a 'new' bike.

Do you swap them with OEM? Or something aftermarket?