borley1863

Hi, i have an MCD monster Truck. It has the CY 29cc billet engine in it, i have heard bad things about this engine which may be true as i ran the engine in, then on my first run once tuned with a jetpro pipe after 15-20 minutes it cut as i slowed and since then i have not been able to start it!
I have tried tuning it different, checked the plug, even changed the carb for a new one but to no avail.
My point is i have 2 Zenoah engines one 26cc and one 23cc converted to 29cc, i had another Zenoah 26cc on my old truck and have never had problems with these engines.
So will a 26 Zenoah be as powerful as the CY in torque and revs as i just might not bother with the CY if i`m already having these kind of problems.
The only hassle is i will have to mod the engine to fit an MCD!
Any help appreciated.

Thanks

Guy

slawhammer

Some CY29cc engines had a bad cylinder inner chrome plating problem...I was known to flake off...cause problems...
The sen 26 cc is a good power plant..plenty of rpm....may not be as much low down torque as the Cy29 cc engine was...
Your zen 26cc should give you plenty of enjoyment for your unit.......
The zen 27.2cc is a very good snappy engine.....rpm's plus some torque..........Slawhammer

Croozer

My Feedback: (1)

I have never had a problem with Zenoah engines, I am working on a Rampage MT which came with a CY 23cc engine but I am adding a race ported 28.5 cc kit to it right out the box.

slawhammer

To my understanding the CY 29cc engine was the only engine to have this problem with the chrome plating...
from what pictures I have seen and different stories I have read about the CY29 cc engine.......
I my self had a billet Cy29cc engine..never had any problems with that.....Seem to smoke a little ..but that may have
been the 2 stroke oil I was using before I switched to Klotz 2 stroke oil......Slawhammer

Ballistic Lunacy

I've seen chrome failures on all sizes of new CY engines, their chorming is really hit'n'miss.

Foxy

Zenoah, definitely.

borley1863

Took engine head off and exhaust no obvious markings in the cylinder or on the head! I think i will put in my Zenoah which has been upgraded to a 29cc, only problrm i have no cluctch and no housing on this engine, can i take take the housing off a CY and put on a Zenoah? I know the clutch will fit.
Looks like i will have to get a piston stopper off of ebay to to this job[]
If i hadnt got this car at a bargain price i would be seriously peeved, i mean a £200 engine in total lasting about an hour!
Thanks

Guy

46u

My Feedback: (3)

Supposedly the CY plating has gotten better. No I do not think a CY is as good for the most part as the Zen. Now there are some Zen engines that have problems like the 4 bolt Zen with the dual bearing on the power take off side that is known for sucking air and dirt. I just wish Zen make a 36mm cylinder.

slawhammer

Ya don't need a piston stopper...just use about 10 inchs of small nylon rope...take out spark plug..put in rope..roll the piston to up till it stops..your good.
Yes the Cy clutch housing and clutch will work on the zen lower engine case....I have done that on my engine...You can buy a piston stopper later..
this will get ya going for now.......I my self have always used rope......Slawhammer

slawhammer

46u..that extra bearing your talking about..on the G270..you take that bearing out and install a extra oil seal there....Then it is fine....Slawhammer

dc2 man

hello

i can GURARNTEE you that you have lifted that cylinder head from the crank case when you mounted your jetpro pipe,i have had a cy engine,man they are good,no crap,they are not bad at all......

jetpro pipes have rubbish mounting designs man.

you mounted it tightly i bet yeah?

simple check/fix here my friend,check your two head bolts,first you will need to take off your billet head(four small bolts on top man) and that will give you access to your main cylinder head bolts which i can lay down money you loosened when mounting that pipe.............engine head lifted drawing air into cylinder thus making it impossible for you to restart........ problem solved.

check this man and let me know,i will be dammed if im wrong lol

just retighted and off you go,GOOD POWER WITH THAT PIPE..that motor has a high displacment with a 2mm stroker crank....awesome low down grunt with good top rpm.....

let me know quick im impaitent now to hear feedback..... lol

46u

My Feedback: (3)

Yes I know this but you should not have to totally disassemble a BRAND NEW engine to fix a design defect? Just thought Zen was better then that. Then the 813 carb that comes on it some have good luck with them and others have to change that to.

Ballistic Lunacy

813 is a tricky carb but it pays you back with perfromance, your either good with it or not. Kinda like Nitro tuning - its a knack.

tom111

Hi borley1863,

I have the same truck as you & I had on it the CY 29cc billet head engine, when I first installed it I couldn’t even turn it on, you were lucky to get 15-20 minutes!!! After many tests & even a special engines workshop that checked my engine, the conclusion was that I am having a pressure leakage from the billet head, when you open the billet head there is a copper gasket that just does not do its work, I think that billet head engine are just worthless, it does not make sense to have an engine with another weak point that some pressure can leak from, the standard engines have 1 gasket for the big bore & the billet engine has 2… anyway my point is that you can try sealing that billet head or replacing the entire engine (same as what I did…) last month I installed a new 30.5 cc CY engine, it has plenty of torque & power & so far it works great, I think that the 30.5cc CY engine will be better than the 26cc Zenoah since the MCD MT is really heavy & 4WD, it requires a lot of torque & power, I have a 26cc Zenoah on my FG & it seems to me as if it has less power… I guess you can try the 27.2cc Zenoah, that might be good.

You can refer to this site for some info on different engines & the power that they supply:

http://www.lunatikengineering.com/home.html

Good luck!

borley1863

Thanks for the replies people, dc2 man, i tried what you said and the 2 head bolts are rock tight so it can`t be them, getting the billett head isn`t a matter of just removing the 4 bolts either unfortantly.
You have to take the pullstart cover off just to get to one of the coil screws that goes into the billett head lol.[>:]
Also dc2 man, do you get a very slight leak of oil round the Jetpro gasket? It is tight it`s just there is a bit of residue.
I have inclosed some pics any other ideas would be appreciated.



Thanks

Guy

GT100

My Feedback: (1)

I like zenoah as well but I do own a CY29 that rips. Its the version that came with the stuffed crank. But if you already have a zenoah that was converted to a 29CC then you have a CY top because last I'd heard, zen didnt make anything larger than a 26CC top. If youre ok with that one, then I guess its like Ballistic said, they're just hit-n-miss on their plating.

dc2 man

WOW.....

i thought that was your problem man,now im just baffled....
cant figure it out,unless your coil is not working properly,all wires on there ok,have you good spark to plug?

cant possibly be an engine problem so,must be carb,had you ever carb off it? you do know that the bottom fuel line to carb is feed from tank and top is return,also if you had carb itself apart the gaskets inside need to be in correct order with diaphram gasket on bottom and plastic type one on top.

simple things but would cause the engine to (not start) lol

also on the intake manifold that gasket between the manifold and carb needs to be on the right way other wise you will block the pulse port causing engine not to start.ahh maybe you used your old carb and made this mistake,on the bottom of your intake block aka isolator block there is a small hole the gasket needs to allighn with this to prevent lack of fuel from carb.

if this isnt the prob then i dont know man,its strange,what mix you run?

as for jetpro.new gasket will not leak if you apply the right torque to those bolts putting them on there.

an old gasket is a pain in the butt as they always leak no matter what...

also change plug just in case........

let us know man,dont give up on this engine,its the same as one i have for sale right now but it always ran great for me with no bother and made great power.

better than zen 26 low down but just a bit shy top end then but not a major differnce either,good wheelie popping power especially with that jerpro,jetpro should give you another 1hp gain on that man.

dont give up on it just yet,must be something simple........

check all above and let me know please.

now im convinced its either that carb gasket on the intake mani or the fuel lines on wrong way around,either way we are eliminating as we go along here so thats a start

p.s man as for that statment about that top copper gasket losing pressure i would be taking that with a pinch of salt now,as mine was taken off a few times just to do checks sometimes and clean and never gave me a bother,anyway who replaces an entire engine over a gasket..

not saying that it didnt give the man the problem that he stated it did but mine was always fine.

dc2

dimag093

Zenoah
Hands down
[8D]

borley1863

Hi dc2, yeah i have tried 2 carbs after i couldn`t get it to start after numerous tuning i changed over for a new one which i had in my box still no luck.
It has a good spark and i initialy tried a new plug that i had, no luck. I might try the coil from a Zenoah i have in bits you never know might be a bad spark. Both plugs are sparking though, tried by doing the old plug on the head trick.
otherwise i`m a bit miffed.
Thanks

Guy

tom111

Try replacing that copper gasket, 99% that this is the issue, pressure might leak from there & due to bad compression it won’t start.

dc2 man

well i never had an issue with mine,but im baffled now to hear this man,try what the lads are saying so......

i would prefer zenoah any day to the cy thats all i use now i have a cad raceported engine coming for my fg now in the 26th this month,750euro motor.

but when i used my cy like yours i never had any bothers,maybe your unlucky with a faulty one man.

besto luck.

splcrazy

those billet heads are crap , i used it once and it overheated bad and then it never started ever again , the two piece design has poor heat transfer to the billet head cooling fins or rather the cooling fins retain the heat rather than getting rid of the heat , the thin copper ring to seal both halves together does a very poor job no matter how tight you do the bolts and no matter what kind of sealing goo you use . I would say use the ZEN first if you want trouble free reliable performance for ever , then use CY heads if you want more power cos they are the ones that only go bigger to 35mm and 36mm . What would be good is if DDM sent ZEN heads to get bored out to 35mm and 36mm then get them sent out to get the bore plated with high quality nickel plate , it would be an unbelievable seller that i bet they would not be able to keep up with demand if they did that

borley1863

Thanks slpcrazy, i have come to a couple of decisions and need some advice thanks.
I have the converted Zenoah 23cc to 29cc which i will probably install after a bit of modding for an MCD vehicle and putting a clutch and housing on.
Another option, is it worth getting the standard head for my CY? I wil buy the chrome head shroud as well as it`s cut down for the billett head.
Also i have a Zenoah 26cc in pieces which apart from that fact i damaged the piston[>:] when taking apart i know runs fine as i had it in my FGMT,
now i would like to buy a new head and piston for this any good tuned kits for under around £120, remember it needs a lot of torque as it may be going
in a heavey MCD MT! Prefebably places in the UK!
Thanks

Guy

splcrazy

well if you want a torque monster out of your stock crankcases this is what ive done to my heavy FG MT, i kept and am using the stock zen cases and installed a 2mm stuffed stroker with zero drag seals with a raceported 36mm ESP head to get it to 30.5cc its a top performer im very happy with its power it really gets the truck moving to scary speeds , remember to grind out the rectangle on the edge of the crankcase bowles when going to 35mm and 36mm pistons, otherwise you will end up putting a huge score line marks on the cylinder bore and kill the piston . you don't need to use an esp head , you could very well just use a stock CY 36mm head and then stack copper gaskets a 020 & 040 together if you use the 2mm stuffed stroker beacuse of clearances

dc2 man

or you could buy mine,an o neills 27.2 race ported full engine,doing a very very special offer at the moment on it,you would be paying shipping of course,cause its been sold atan already unbelivable price.

its a zenoah with a raceported 27.2 piston and cylinder fitted and has 2mm stuffed stroker crank,just needs coil and pullastarted to complete.

pm me for more info as this is not sales section.