2004 Suzuki GN250 issues: smoking like crazy, burnt oil smell

[SJizzle]

Hi guys. I recently put another motor in my gn250 as the old one was completely shot. Today I filled up the second hand motor I got with oil 15w40 oil run of the mill type and she ran fine for about twenty minutes until I took her for a ride. All of a sudden I smell burning oil and a whole bunch of smoke is coming out the exhaust. Any theories as to what may cause this? I am a car mechanic by trade and admittedly this is my first time working on motorcycles.
Any comments would be helpful.
cheers guys
Sj

[ducatilover]

Over filled? They only take 1.3L of oil
Do a compression check.
You can buy a barrel and piston for $150 locally (cheaper from China)

A GN motor works like a cars...

[skippa1]

Check the engine on the garage floor....chances are it's the good one......pickin you took the fucked one out, went upstairs for a cuppa, came back and reinstalled it



PS.......a car mechanic should know what the likely culprits are.......it's only a 4 stroke motor ffs

[nzspokes]

Check the engine on the garage floor....chances are it's the good one......pickin you took the fucked one out, went upstairs for a cuppa, came back and reinstalled it



PS.......a car mechanic should know what the likely culprits are.......it's only a 4 stroke motor ffs

Many years ago I worked as a lawnmower mechanic. Ginny motor is a B&S 4 stroke that stands up.

Mind you a B&S puts out more powa.....

[AllanB]

Over filled the oil? Or the second motor is a dud.

[SJizzle]

Hahaha I know I put the right engine in cos I had to swap over some bits from the old one that was missing on the one I just installed. New motor is a japanese one from an older gn. Maybe car oil is not ideal for it?

[SJizzle]

Over filled? They only take 1.3L of oil
Do a compression check.
You can buy a barrel and piston for $150 locally (cheaper from China)

A GN motor works like a cars...

No compression issues bud. Just a whole bunch of smoke under throttle

[skippa1]

Hahaha I know I put the right engine in cos I had to swap over some bits from the old one that was missing on the one I just installed. New motor is a japanese one from an older gn. Maybe car oil is not ideal for it?

Depends on what part of the car you took it out of, the diff oil might not be so good.

im no oil expert but I have always used motorcycle specific oil as it cost fuckall more, seems like false economy to use car oil for the sake of a few bucks

[SJizzle]

Depends on what part of the car you took it out of, the diff oil might not be so good.

im no oil expert but I have always used motorcycle specific oil as it cost fuckall more, seems like false economy to use car oil for the sake of a few bucks

I used SAE 15w40 sinopec oil. They are one of my suppliers. Engine oil not diff oil. I may drain the oil tomorrow and put in some Motul 10w40 as the service manual recommends that particular viscosity of oil

[AllanB]

Blocked crankcase breather or something forcing oil into the air box? Check the air box - it should be nice and dry in there.

[ducatilover]

No compression issues bud. Just a whole bunch of smoke under throttle

What'd the comp test show? Dry/wet hot/cold?

You have a GN, which fucking sucks

[SJizzle]

Blocked crankcase breather or something forcing oil into the air box? Check the air box - it should be nice and dry in there.

Has no airbox. Has a pod filter ans breather hose is just there not connected to anything. Bought it like this

[SJizzle]

What'd the comp test show? Dry/wet hot/cold?

You have a GN, which fucking sucks

Compression test showed good results from memory. Did it when the bike was cold. In between working on a customer's car and doing a wof lol

[ducatilover]

Probably oil control ring then.

[Big Dog]

You definitely want bike oil I there. Bikes use the same oil for their tranny as engine. Won't cause your smoke in such a short time , will happily cause your tranny or engine to wear at some point in the future as it becomes less slippery every time it passes through the gearbox.

Smoke is blueish or smells of oil I'd check the head gasket.
Black and stinks of fuel check you have not dropped a valve.
If the engine has spent any considerable amount of time on its side since it was last run rip the headers off and see if you still have smoke.
A mate had his bike on its side to pull the engine out and found it smoking badly whenever the pipes got hot.
Problem not there with the pipes removed and engine hot. Put some degreaser down the header (cold unless you want a fire) swirl it and hang it muffler up. A mall amount if thick black goop dripped I out overnight.
Next day light grey smoke when the pope first heated up, then a bit of a back fire and back to normall.


Stupid phone / Tapatalk, apologies in advance.