Running in and broke down!

paul knapp · Post by **paul knapp** » Sat Jan 21, 2012 2:00 am

I think perhaps being a rebuilt motor, not run in, it was pushing up a bit of oil into the cylinder, which due to the 'sedate' speed didn't burn off, and just fouled the plug. Or perhaps 'whiskered' it.

Not getting into any debate re oil, 10W/40 is for modern high reving multi over head cam engines with close running tollerances, not for these old roller bearing crank, push rod clunkers.
Even in Kiwi land, I personally wouldn't go any lighter than straight SAE40.

...

Trefor · Post by **Trefor** » Sat Jan 21, 2012 2:45 am

How about running in oil or straight 50 to bed in the new rings? I agree with itma a cap full of 2 stroke as an offering to the valve guide god.

en7jos · Post by **en7jos** » Sat Jan 21, 2012 3:09 am

It seems that Redex "upper engine lubricant" is no longer available, as modern fuels allegedly have the required additives in already (or at least the additives required by modern engines). Not sure any of the current Redex products are equivalent or will do the same job, waiting for a response from Holts to confirm.

Interesting reading on the back of the old can though - a real miracle product. Surprised it didn't also suggest adding it to your morning cuppa to get peak rider performance too!

That 5litre can in your garage could we worth a small fortune Ken

fump · Post by **fump** » Sat Jan 21, 2012 4:06 am

Thanks for all your inputs. I have had a look at the pushrod adjustments and all appears okay. Nothing appears broken as far as I can see. The engine starts okay from cold and can be restarted a few times, but once it is hot then restarting becomes a problem. Compression is fine and spark appear fine and I cannot see why fuel should be a problem but....... then why is the hot starting a problem?

There is one thing I forgot to mention........The pilot jet on the "concentric" carby has always to be set right in (clockwise) no matter which needle setting I select and I have tried all three.
Maybe a clue there.....

I have just about had enough with this bike, one problem after another it's been nothing but a pain in the A#$= and leg ever since I bought it 8 weeks ago!Edited by - fump on 21 Jan 2012 04:15:00 AMEdited by - fump on 21 Jan 2012 04:36:03 AMEdited by - fump on 21 Jan 2012 04:51:22 AM

rex.webb · Post by **rex.webb** » Sat Jan 21, 2012 8:55 am

Redex Petrol Treatment - 500ml

Redex Petrol Treatment - 500ml

Its here in Cambridge ! You can still but it.
RIDE with CARE and LIVE LONG to ENJOY your Bikes and Scooters .
Insured with Peter James

SPRIDDLER · Post by **SPRIDDLER** » Sat Jan 21, 2012 10:13 am

quote:
there was a strange noise from the front part of the engine and it stopped.
Unless I've missed it you didn't reply to Goldstar's question: What ignition system do you have?
Could the 'strange noise' have come from the mag, if that's what you have?
What year's the bike?

It's unlikely that the position of the needle would have any effect on the pilot jet adjustment as the needle regulates fuel from the main jet.
I've never had a concentric but I don't think the pilot should be screwed right in (max richness at small throttle openings when starting). If you are having to screw it right in it's a possibility that you have an air leak at the carb to engine interface.

Give the old girl a chance - 8 weeks aint much to get her sorted. Mine's taken me years

Cerberus · Post by **Cerberus** » Sat Jan 21, 2012 1:41 pm

"pain in the A#$= and leg ever since I bought it 8 weeks ago"

It took me almost 12 months to sort out all the little niggles on my M16 after I purchased it (ostensiably going). I got very despondent about 2 months in, but after a whole catalogue of small to medium problems: condenser, pitted contact breaker surfaces, auto-advance springs weak, worn carb slider, cracked insulating block (between carb and inlet), carb face that looked like the top of IKB's Tamar Bridge. Since sorting them all out then it's been running like a dream (famous last words), started first kick this morning.

1608 · Post by **1608** » Sat Jan 21, 2012 10:35 pm

The more common reasons for poor or non-starting when engine hot is either, rich mixture ( possibly flooding ) or weak mag / condensor. Remember, that the plug may spark when laid on the outer casing of the engine , but may not spark when under compression. A simple test of the mag is to see what if any spark is produced when the plug gap is widened to 1/4" to 3/8". A good mag will manage that gap. This is one reason its not a good idea to exceed the recommended plug gap which just stresses the mag making it work too hard.

fump · Post by **fump** » Sun Jan 22, 2012 7:04 am

Thanks for all your comments and suggestions. It's good to be reminded that other folk have had the same experiences with these old machines.

SPRIDDLER/1608 The Ignition is the N1 Magneto and I am sure it is fine having had it on the bench examined and re-installed and re-set up.
However that strange noise could have been the Mag it was somewhere near the front of the engine. But all appears okay now.

I took the carby apart this morning and cleaned it out with solvent and made sure the pilot holes were clear. Re installed and took particular attention to eliminate any possible air leaks in the inlet.
Also put the needle back on the middle setting.The pilot jet setting is still best at fully clockwise. But I can live with that for now at least.

She started first time and ran well from cold. I then did a ten mile ride and all was well. I wasn't up to trying the hot start! So at the moment I am happy..I started taking her apart 14 days ago and now all appears well with re-bored barrel and new +20 thou piston also valves checked and lapped. No more excessive fuming from the crank case and she now has plenty of compression.

I think I will change the oil and go to SAE 50 good stuff...... now about the questionable front brake performance............Edited by - fump on 22 Jan 2012 07:13:58 AMEdited by - fump on 22 Jan 2012 07:17:54 AM

bigwol · Post by **bigwol** » Sun Jan 22, 2012 8:54 pm

now about the questionable front brake performance............

Dont expect too much from the front brake! Cable operated single leading shoe drum will never be a great stopper!
De glaze the shoes, clean all the dust out and centre the shoes when you re-assemble, then adjust and be prepared to accept that what you end up with is the best you will get!
Ride allowing more braking time and room and ready to stamp on the rear when required!