Have i just blown my bike?

[Martay]

Hi,

Just popped to town on my SH50, rode there absolutely fine. On the way home, it started loosing power. I was sat at 35ish then the speed started dropping off slightly, down to about 29 when the engine stopped suddenly locking the rear wheel.
I had a little tinker at the side of the road, checked the plug, the tip was a tan brown colour. Drained the carb. The bike restarted but wouldnt idle. I rode it about 100yards to a layby and it locked up again. It now will not start The 2t oil is full, its got fuel. It cranks over on the starter. It has spark, not a fantastic one but consistant.
Any ideas?
Ta
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express

[R6 Wilson]

Doesn't sound good at all, have you checked the drive-belt? I'd say take the cylinder head off and have a ganders
____________________
♥ YZF-R6 '05 ♥
Time is money so I stay late

[stinkwheel]

Certainly sounds like an engine seizure to me.

Only way to find out is to pull the top-end off. You can sometimes see scoring on the piston if you peer through the exhaust port with a pen torch.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Martay]

Hi,
well, ive set to with the spanners, its not looking healthy. I think the oil pump may have died, the supply line to the carb is bone dry inside
Got the cylinder off, the piston has started to melt and turned an interesting colour, and bits of piston are stuck to the bore! Im guessing its not good?!
Bottom end:
what are the chances of the bottom end being salvagable? Ive got the piston off the rod, all looks well inside. Theres a tiny bit of sideways movement in the big end bearing but no up/down movement. Ive popped some 2t oil into the bottom and been spinning it round by hand to lube it all up.
Il pop a piccy up in a sec
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express

[Martay]

https://i279.photobucket.com/albums/kk125/MartayP/P310711_14440001.jpg

https://i279.photobucket.com/albums/kk125/MartayP/P310711_14450002.jpg

https://i279.photobucket.com/albums/kk125/MartayP/P310711_14460001.jpg

https://i279.photobucket.com/albums/kk125/MartayP/P310711_14470001.jpg
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express

[R6 Wilson]

I'd agree that it was not good

If the problem started with the piston melting I'd say there was a fair chance the bottom end is salvageable
____________________
♥ YZF-R6 '05 ♥
Time is money so I stay late

[pepperami]

? looks like you might be able to salvage that? hopefully? possibly? maybe?
A tiny bit of sideways play need not be a problem.
Hold the crank still and see if the con-rod can be moved up and down whilst the crank is held tight........ if it moves then you could have bottom end problems .

Now I remember why I was such a fan of pre-mix!
____________________
I am the sum total of my own existence, what went before makes me who I am now!

[Martay]

Hi,
thanks for the help. The oil pump is infact dead. Popped it out, whacked it in an electric drill, it doesnt move any fluid. I even primed it and re-tried. It makes a whining noise but not alot else! Its pissed me off, ive always made sure its got oil and smoked. It was smoking when i left, then within a mile or so it seized. Its only done 11k.
Im torn between replacing the pump and top end, or just the top and pre-mix it?
I gave one of these to my friend to use for moped mayhem, im hoping i can buy the engine back off him. He's just replaced the piston and gaskets
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express

[unitynotsocri...]

try n get a big bore kit and pre mix it. 11k is pretty good for a small piston.You can check the conrod/big end play and see wether its within tolerance.if not then why not check out the price for a new engine/transmission ?You might find a bigger bore china clone that would fit.
____________________
nearly a normal tax paying tosser.......with ferrileness suzi100,cg125,cb125scb100n,cb175,cd100,cj250t,kh250,c15,125 bantam,super 6,rickman gs750,xt500,250rs,dt175,lifan125,dolomite1850,metro,Morris220ld,morrisfg,leyland princess,range rover,corsa,vw camper .now struggling with legs. MORE ORDER = MORE CHAOS

[Martay]

The only big bore kit available is a 60cc, but tbh i couldnt see it making alot of difference. On wemoto the difference in price between a standard kit and big bore is about £15.
Theres no vertical play in the big end, and the crank bearings feel fine.
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express

[unitynotsocri...]

When you've 50cc a twenty per cent difference is alot!Youd get a little more lower down power and a bit more acceleration.
____________________
nearly a normal tax paying tosser.......with ferrileness suzi100,cg125,cb125scb100n,cb175,cd100,cj250t,kh250,c15,125 bantam,super 6,rickman gs750,xt500,250rs,dt175,lifan125,dolomite1850,metro,Morris220ld,morrisfg,leyland princess,range rover,corsa,vw camper .now struggling with legs. MORE ORDER = MORE CHAOS

[Blau Zedong]

My YR5 suffered an oil pump failure which murdered the top end. I never touched the crank when I rebuilt it because it felt ok. It's still fine three years later. Roller bearing cranks can take a lot of shit.

And Wilson, stop giving crap advice plox.
____________________
18:54:48 Rob Fzs: jews don't give away stuff for free

18:54:59 Rob Fzs: unless its their clothes/ hair/ golden teeth

[Martay]

Righto,

Just picked up an almost complete spare bike to fix mine up with! I gave it to a friend several months ago for moped mayhem. He rebuilt the top end, put most of the bike back together then ive just bought it from him. Well, when i say 'bought' i didnt take any cash, so i still owe him!

My questions:
If i just swap over the engine unit, do i need to tell DVLA? The plan is im keeping my carb etc and putting them onto the replacement engine.
How do i prime the oil pump? Or should i block off the oil pump and run pre-mix? The oil pump is linked to the throttle cable, so it has no set mix ratio, so what ratio would i use?
Ta's
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express

[P.]

[trisers]

Firstly, swapping the engine over will mean you should inform DVLA...the replacement engine obviously has a different number which won't tally with the V5.

If you're going to use the oil pump for the 2t oil then the way i primed mine was to put a little premix in the petrol tank first, fill the 2t oil tank then disconnect the 2t delivery tube from the inlet manifold. I then found another small piece of tube to connect to the manifold which i plugged with a suitably sized bolt to stop an air leak into the manifold.

Start the bike and holding the free end of the pipe coming from the pump in a rag just wait for the oil to appear in a steady flow without any air bubbles...mine (honda) didn't need any priming and it only took about 30 secs for the oil to start coming through nicely at about a drip every couple of seconds. Stop the engine, remove the spare plugged piece of hose, connect the tube from the pump back to the manifold, run the engine again just to make sure you didn't let any air in while reconnecting and the job's done.

Lastly fill the tank right up with petrol to dilute the premix in it right back down again.

The choice is yours if you want to stick with premix, but if you do the handbook should tell you the mix ratio although the 2t oil bottles i've bought all give a suggested ratio for their product on the label....

[chris-red]

[Martay]

Sounds like a plan with the 2t pump

I may have changed my mind re engine swap. I dont know if its the bottom bearings or the clutch but something makes a rumbly loud bearing noise when i kick it over.
So, im now thinking of pinching the top end and oil pump to put on my bottom end + carb. Il post some pics when im done
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express

[benandthe]

I've never trusted oil pumps, never know when/if they are going to pack up, so I've always pre-mixed at about 33:1 (150ml oil to 5.15litres of petrol).

If you go pre-mix, my advice is buy a jerry can and always mix in there, that way if you don't use it all you wont have filled your petrol tank with too much oil.

Also, don't forget to upjet the carb to allow for the oil, say you're running a 54 main jet, go up to something like a 56/58 and you will be fine.
____________________
Sold: NRG 50cc, SR125cc, CBR125cc, Mito MK 1 125cc, Speedfight 50cc, Stomp 125cc, cbr125cc, NRG 172cc, CBF 125cc, Zip 70cc, stomp 140cc
Current: CB500 (waiting on DAS)

[Martay]

Hi,

Ive decided to run the pump, if it proves problematic i will go onto pre-mix.

GOOD NEWS! She runs!! Got the engine built up, back in and running! Im running it premix at the mo to prime the oil pump. So pleased Shes quite smokey. I think i mixed it a tad rich. Looked like fruit squash in the jerry can
Couple of Q's:
How much oil should the pump deliver? Ive got the engine idling and it drips once every 30 seconds, at full throttle once every 15 seconds. Ive had the engine running for about 20minutes on premix and i think most of the air is out of the pump.

Some photos for ya:

The doner bike
https://i279.photobucket.com/albums/kk125/MartayP/P030811_15030001.jpg

Engine removed
https://i279.photobucket.com/albums/kk125/MartayP/P030811_15070001.jpg

Offending parts
https://i279.photobucket.com/albums/kk125/MartayP/P030811_16130002.jpg

The 'pump priming' setup
https://i279.photobucket.com/albums/kk125/MartayP/P030811_17230001.jpg
Bottle to catch the 2t oil, on the left a big fan keeping the engine cool as the casings arent on to direct the airflow from the fan on the flywheel
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express

[benandthe]

Have you switched the whole engine or just parts? if it's the whole engine, don't forget to tell the DVLA.
____________________
Sold: NRG 50cc, SR125cc, CBR125cc, Mito MK 1 125cc, Speedfight 50cc, Stomp 125cc, cbr125cc, NRG 172cc, CBF 125cc, Zip 70cc, stomp 140cc
Current: CB500 (waiting on DAS)

[trisers]

[Pete.]

Most stroker oil pumps have a priming screw on the pump body. You remove the screw until oil comes out then re-fit it.

Oil pumps are by their very nature reliable, they are full of oil after all (or should be).
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[ThoughtContro...]

[Martay]

Hi,

In the end i only swapped parts onto my engine. I think the main bearings were on their way out on the replacement one. I just took the oil pump, cylinder, piston/rings, gudeon pin and small end needle bearing.
Unfortunatly i dont think the pump has a priming screw. I had a quick ganders in the Haynes and couldnt see anything.

One last thing, what do you do with the handful of nuts/bolts/fixings left over after ypu've rebuilt the bike!? Apparently thats the sign of a good mechanic, getting it all back together and working correctly with bits left over
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express

[Martay]

Sorry to re-nudge this but it saves a new thread.

Running in: How do i run in a moped after a new piston + barrel? I understand i need to go easy on it, but by its nature i need to almost full throttle it to move off.
Ta
____________________
Eat well, poo hard
Drives: Cavalier 2.0 16v
Rides: Slightly ratted Honda City Express