NEW Zenoah 27.2 ESP Ported & Mod'ed 4 BOLT

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mik3y

mik3y

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Just got the engine for the Baja yesterday.

I am going to be using stock pinion gear and robinson racing 57 tooth (stock ratio). Any recommendations?
 
Nice choice. I run the same motor but the 2bolt.


Read thru Dougs Tuning Sheet.

He does NOT favor babying a motor on break in (seating the ring)

25:1 oil/gas ratio.
start it up, warm it up, get it roughly tuned to idle well and spool up good, get to higher rpms fairly smoothy (rear wheel off the ground).

then run it. run it well. don't baby the motor, its a motor, not a child.
Durring the first few runs, follow Dougs tuning guide and do some runs then plug checks. If you have a Remote kill switch, use it for tuning. i run at the RPM i want to check, and kill the motor with the switch after 10 or 15 seconds. this give me a very TRUE TO RPM read of the needle settings by "Reading" the plug color.

go for a medium brown plug color like a broken open hersey chocolate bar.
this should only take a few minutes to do, say 10 or so.

once your confident your needle settings are good and a bit on the rich side, run the motor like a red headed step child.

after 15ish minutes of running, bring it in and shut it down, let it cool for 20mins.

restart and do it again.

on the 2nd tank, tweek your needles as you see fit ( you may find you want to adjust them during the 1st few tanks to get good performance. go ahead, just be sure to leave your settings a Smidge rich for the 1st 2 or 3 tanks), and don't look back.



just keep up with your maintenance, filter changes ect, and enjoy that brute of a motor.
also after every couple runs, check your bolts (carb during filter maintenance) exhaust and cylinder bolts, to be sure they are tight. sometimes on new motors, the bolts may like to come loose, though i have never had this issue with one of ESPs built motors.


you ll want to re ring the motor probably between 5 and 7 gallons thru it to keep it running strong. i waited till 12 gallons to redo mine (purposly pushing it to the limits of needing rebuilt) but it should of been done around 5, as i did start to notice some performace loss as the ring continued to wear down as gallons passed.
 
@timmah

thank u very much for the advice. Can u please explain to me what you mean by "reading the plug color"? What is the purpose and what should I be looking for or understanding from the colors.

ThAnks
 
when you take the plug out after a run, you ll see it has some color to the electrode area.

that color can tell you LOADS of information on how the motor is running.

when you run at a steady rpm for 10 to 15 seconds, the color on the plug will change a bit, reflecting the tune of the motor.

a black oily looking plug is Way rich. (think carbon black and wet looking)
a Black dry plug is rather rich (think carbon black, dry looking
a dark brown plug is a fairly rich (think well done meat, very dark brown)
a med dark brown plug is just a bit rich (where i usually run for bashing, think a hersey chocolate bar that has been broken open. that nice brown color inside the candy bar)
a brown plug is nicely tuned (also safe for bashing) think a bit lighter brown than the candy bar)
A dark Tan, Now your getting to performance tuned. think a very very dark caremel color
a med Tan. this is Performance tuned. if you think of a Kraft Caremal candy, that is about the color of a very well performance tuned motor.
a light tan is getting too lean 9 think a bit darker than a nuegat from a 3 muskateer, between that and the kraft caremel color)
a very light/white color is vey very lean and about to lean sieze. think Ashes or a dark chalk white color.

so as you can tell, looking at the color of the plug (Reading the plug) can tell you much.

if its really dark, your too rich with the needle settings, if its really light, your too lean.

note: a new plug is white. it can take up to two tanks to get some color on the plug to be able to read it. either use a plug that has already been ran and has some color to it, or be sure your rich for a few tanks to get some color built up on the new plug, so it can be read.
 
@timmah,

Thank you so much for the explaination! Now I understand.

I have a question:

What did you mean by using the kill switch to test the various RPMs?

I have a killer bee kill switch. Can you please elaborate on the proper procedure.

Thanks,
Mike
 
my killer B works off my 3rd channel. your may also, or you may have to shut off the TX if you have one of the V2 models.

but run at the rpm you want to check for tuning, ie, say you want to check the low needle setting.

you ll run the baja at no more then 1/4 throatle (as after 1/4 throtle, the high needle starts to flow fuel). so you run 1/4 throtle for 10 to 15 seconds, then just hit your 3rd channel (or shut off TX if using V2 killerb switches) and the motor will shut down, then take the plug out and do the "READ" of its color. there is a plug chart posted here in the motor/exhaust areas that shows plugs, and the corrisponding READ of the plug.

(be sure you check the operation of your fail safe before doing this with motor off, so it does infact shut the motor down, and does not stay running and wot the gas for you.

but anyways, by using the remote kill switch to kill the motor at the RPMS you want to check the tune on, you can get a true reading from the plug for that RPM.

now once you read the plug, say its black and oily, signifying the low needle is set to rich, then lean up the low needle a small amount (i try to work in 1/32 to 1/18th increments), put the plug back in, take another run at the same rpm, shut it down, and re check the plug. adjust if needed. again go for a medium brown, like that hersey bar color i mentioned above. that is a good performing tune, but still rich, and should be safe, yet powerfull motor performance.
 
Does the plug colour change then even if it has gone really black to lighter brown when the the settings are leaned off?
 
yes, as you run the motor, the heat created by the burn/tune will burn off (as the tune gets leaner) or adds to (as the tune gets richer) to the plug color.

so a black plug that is leaned up on the needles will start to lighten in color to represent the current needle settings.
that is the reason for the 15 second run at a steady rpm. in that 15 seconds, the color should change some with the needle changes just prior to that run.
 
Thanks Timmahh and mynameismud76, anyone previously confused about spark plug colour now shouldn't be!
 
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Kinda of upset today :(

I just went on Daves motors website and saw that they have a new Zenoah 30.5cc 4-Bolt ESP Modified and Ported Engine for $499.99

Last week, I purchased the same engine but the 27.2cc for $499.99 and now they lowered the price to $475.00 since the 30.5cc came out.

Is there any REAL and Noticeable difference in a 30.5cc ESP Ported and Modified 4 Bolt engine vs. 27.2cc ESP Ported and Modified 4 Bolt engine?

Timmah...Any input from you?

Thanks
 
IMO the 27.2 is a GREAT overall motor. The 30.5 will be more torque but less RPMs this will get you less top end. In a Baja the Rpms are a must IMO in most driving conditions. The Torque comes in sand type applications.
Can't go wrong with the 27.2.
 
I am only using my baja for On-Road applications.. No sand, no dirt. I put on Hostile Slicks and am primarily looking for top end speed.

So im glad to hear that the 27.2cc is actually a better choice for my application.

Can you explain why the 30.5cc gives less RPMs and More torque vs. the 27.2cc?
 
the both actually rev out about the same, but the 30.5 pulls more load from producing more torque.
the more torque is created from the larger bore. no replacement for displacemnt anology comes to mind.

but in general, the smaller ligher piston/bore of the 27.2 should give you a bit more top rpms than the 30.5. but again, its not a huge differance up top, the main differance is the additional torque. again not alot but it is a noticable differance.
 
Thanks for the explaination Timmah

You are right, there is no replacement for displacement.
I guess for my application of on-road use, the 27.2 should be enough =)

I guess ill get the 30.5cc for my FG MT5 truck :drool:
 
dicplacement. the larger bore just naturally creates more torque. also being larger, its typically heavier, thus the less top rpm. but with that said, i ve seen some of the 30.5s make just as much top rpm as the 27.2 (sometimes more) and be able to pull taller gearing.
 
@ Timmah,

Speaking of gearing,
I have a 57tooth robinson racing spur gear and 17 tooth pinion gear (stock set up).

What do you think about this gear set up and the 27.2cc ESP motor? Do u think / recommend getting a different gear ratio set up?
 
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