greed1

hi all

having problems with my Oniell 27.2

hard to start but when it is started i has an erratic idle
then it wont accelerate and just dies when i use the throttle

i have changed the spark plug

plz help

graham

DarkFire989

You might have a airleak. Check for one.

greed1

were could the air leak be and thanks for the fast reply

greed1

i think there may be a small crack in the jetpro exhaust but i wouldnt think that this would case the problems

46u

My Feedback: (3)

Make sure the exhaust header is tight and not leaks. Check the isolation block for cracks, leaking and make sure it and the carb are tight.

Is the engine new or have you had it a while?

greed1

i have had the engine around half a year
it is a bit dark now to do anything to it but i will have a look tomorrow

what is the isolation block

sparky 25

Also check the carb needles as while i was tuning my km baja the tune went way off,

i had real bother trying to find the problem but i put it down to the carb in the end,

i was about to purchase a new carb when i screwed out the carb needles

and the low end needle was missing a small piece at the tip ,

which was stuck in the carb sending the idle and low end way off

46u

My Feedback: (3)

The plastic or if up graded aluminum part between the cylinder and the carb. It is to keep the heat of the engine from getting to the carburetor. They are none to crack and leak. Make sure the carb and the bolts to the isolation block are tight.

Did this problem start all of a sudden?

greed1

just checked the carb needels and they are fine but thanks for the help also checked that the carb is on tight

any other ideas
graham

46u

My Feedback: (3)

Do you have WD 40 over there? If so start the engine up and spray some WD 40 around any where there is a gasket but keep it from going down the air filter as this will give you a false reading. But if you have an air leak the engine will either rev up or die when you spray it if there is an air leak.

Been using this method for years on trying to find intake leaks and leaks on 2 cycle motorcycles.

greed1

ow i c
the isolation block is aluminum havent checked for crack yet

the engine seemed to get hot and stoped then from then i have had the problem

i dont know why it got hot it worked the day before


i will try the WD40 tomorrow and yes we do have it over here lol

46u

My Feedback: (3)

Is this the engine you have ?
http://www.oneillbrothers.com/rccar/...c_machined.htm

46u

My Feedback: (3)

If you have an air leak this will make the engine run lean which in turn will make the engine run hot.

46u

My Feedback: (3)

Or is this the engine you have that is the 4 bolt Zenoah? If it is a 4 bolt Zenoah they have a dual bearing on the clutch side which are know for developing air leaks. Most take out one bearing and put a seal in its place.
http://www.oneillbrothers.com/rccar/...mod_g272rc.htm

greed1

yes that is the engine i have well i think i have came with the car but i had to buy a cylinder and piston




that makes sence i will try the WD40

if it is a leak will it only need a gasket

greed1

lol u keep replying so fast i dont have time

i think this is the engine i have

http://www.oneillbrothers.com/rccar/...c_machined.htm

TheFgMan01

Cylinder gasket my friend... trust me

46u

My Feedback: (3)

If it is the WD 40 trick will find it and very well could be. If it is when replacing make sure you torque it to the recommend torque value and best when it comes to the engine to torque anything on the engine to the recommend torque value.

SAVAGEJIM

Wow, how did you break that tip off? I have bent a tip on one of my engines, but never have I broken a tip like you did. You must have totally trashed the engine for the needle to take that kind of damahe.

46u

My Feedback: (3)

Keep in mind it was on a stock KM engine and we know how they are made.

SAVAGEJIM

True, brittle steel = tips chipping and breaking off instead of bending. []

46u

My Feedback: (3)

No telling what they are made out of!

greed1

thanks for all the help again but now i have taken the needels can you tell me the needel settings

so i can try the WD40 when i get home

regards graham

Mudgy

isn't a plastic insulator plate supposed to be way way better than some bling metal one? (something about heat expansion)


WD 40 is a good way to find a vacuum leak in 4 stroke intake manifolds, and the jungle of hoses attatched therein....

SAVAGEJIM

Yes, definitely. I know for sure Zenoahs have a plastic "manifold" spacer between the engine and the carb, and that is exactly what it is designed to do: function as heast insulators so the carbs dont get massive amounts of heat transferred to them.