HPI Baja 5SC - Help Needed

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RC Master

RC Master

Active Member
Messages
41
Location
Middle of the Desert
Hi my Baja 5SC ran well on the first pull this morning, did some laps and tuned the H and L needles.

After say 10mins the engine died

And it won't start even after

I changed the spark plug

I checked the plug has sparks when pulled

I checked and cleaned the igniter

I checked and cleaned the Walbro Carb WT668B, diaphragm is clean and has the indent on the corners still

What am I missing??

Engine is not flooded, removed the plug and pulled 15-20 times and turned the engine upside down.

I am dumbfounded on this problem of mine.

note: when I did laps in the morning, I was tuning the L and H needle and it was working well, white smoke on acceleration and the car was moving at a good pace.
 
RC Master said:
Hi my Baja 5SC ran well on the first pull this morning, did some laps and tuned the H and L needles.

After say 10mins the engine died

And it won't start even after

I changed the spark plug

I checked the plug has sparks when pulled

I checked and cleaned the igniter

I checked and cleaned the Walbro Carb WT668B, diaphragm is clean and has the indent on the corners still

What am I missing??

Engine is not flooded, removed the plug and pulled 15-20 times and turned the engine upside down.

I am dumbfounded on this problem of mine.

note: when I did laps in the morning, I was tuning the L and H needle and it was working well, white smoke on acceleration and the car was moving at a good pace.
Click to expand...

How old is it an how long has the truck been sitting before you started to run it from being stored?

If it has been stored for a long period ,then your fuel lines an fuel filter may need to be replaced!...:cool:
 
1) check for spark - remove plug, connect to wire and press plug to exhaust for metal to metal contact, now pull the pull start - you should see a good spark
2) does the priming bulb work on the carb? do you see fuel flow through?
3) is the air filter clean?

star with that, air, fuel, spark.
If it looks good, then next step I would do: remove the carb and try starting the motor. The upside down pull the pull start doesn't work (I know from experience) It is probably flooded now. This should de-flood it.
 
enzo3856 said:
1) check for spark - remove plug, connect to wire and press plug to exhaust for metal to metal contact, now pull the pull start - you should see a good spark
2) does the priming bulb work on the carb? do you see fuel flow through?
3) is the air filter clean?

star with that, air, fuel, spark.
If it looks good, then next step I would do: remove the carb and try starting the motor. The upside down pull the pull start doesn't work (I know from experience) It is probably flooded now. This should de-flood it.
Click to expand...


Remove Carb and nothing, the spark on the plug is a bit faint is the spark supposed to be a bit bigger or stronger? My suspect is the igniter, I have check all above and really wrecking my head now and painful shoulders and arms from pulling
cbaker65 said:
How old is it an how long has the truck been sitting before you started to run it from being stored?

If it has been stored for a long period ,then your fuel lines an fuel filter may need to be replaced!...:cool:
Click to expand...

It ran like a champ in the morning, after I cleaned it 100%
 
RC Master said:
Remove Carb and nothing, the spark on the plug is a bit faint is the spark supposed to be a bit bigger or stronger? My suspect is the igniter, I have check all above and really wrecking my head now and painful shoulders and arms from pulling


It ran like a champ in the morning, after I cleaned it 100%
Click to expand...

Just like all 2 stroke engines ,they are un predictable ,mine ran great until it sat in a hot shed for 5 years!

The only thing you can do ,is go back over everything again an see if you missed something ,but it is crucial to make
sure that you start with the fuel tank!
 
cbaker65 said:
Just like all 2 stroke engines ,they are un predictable ,mine ran great until it sat in a hot shed for 5 years!

The only thing you can do ,is go back over everything again an see if you missed something ,but it is crucial to make
sure that you start with the fuel tank!
Click to expand...

Thanks there is no blockage there the fuel goes back smoothly when primed
 
cbaker65 said:
Here is a pic ,it is the little hole that I am pointing at ,there would be one on the gasket & carb ,some times
gaskets will be versitle an have 2 holes ,but some may have one an could be installed upside down plugging
the hole ,also ,it could be an air leak there ,or a warped carb throat!

Click to expand...


Thanks that very clear
Can it also be that the igniter is busted, how can I test that it produces sparks on the plug but very weak
 
It wouldnt run at all of the pulse hole was plugged up. You should have a nice bright blueish spark, from the plug. Only way to check if the coil is junk is with a new one. They normally work or not, have had a few that would break down when they got hot, but normally fire right up once cooled down a bit. If your plug isnt wet, it's not flooded as well. By tuning the fuel needles, how hard did you lean out the high needle? And again how long was this thing sitting? There are 2 diagrams in these carbs. One is for the fuel metering side and the other is the fuel pump side. They get stiff with age and need replacing every now and then. Plus a kit is all of $12.00 or so.
 
Seandonato73 said:
It wouldnt run at all of the pulse hole was plugged up. You should have a nice bright blueish spark, from the plug. Only way to check if the coil is junk is with a new one. They normally work or not, have had a few that would break down when they got hot, but normally fire right up once cooled down a bit. If your plug isnt wet, it's not flooded as well. By tuning the fuel needles, how hard did you lean out the high needle? And again how long was this thing sitting? There are 2 diagrams in these carbs. One is for the fuel metering side and the other is the fuel pump side. They get stiff with age and need replacing every now and then. Plus a kit is all of $12.00 or so.
Click to expand...

Thanks those carb kits are indeed valuable will keep those handy
The engine CY26 is ALIVE

It ran well today, had no room to tune it though just idled it till it warmed up
 
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