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Tiger Cub Rebore?


brucey
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Bruce

Kickstarts fouling footrests is a bugbear of mine too...

re Terry's Kickstarts, he told me if I need to bend it (to clear a footpeg) DON'T use heat, just use a long bar. He then produced about 8ft of what looked like scaffolding pole to demonstrate what "long" meant. I've no idea how you are supposed to hold the other end....I haven't fitted mine yet and haven't decided on footrests either; the cub is such a long term project I ended up buying a TLR200 just so I could get out and ride.

Esteve

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Just a thought:

you said "Timing was set as instructions (align yellow marks with piston at TDC) which I believe is an actual static timing of 3mm btdc."

Have you strobed it to see when the spark is actually occurring?

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Esteve,

I can accept the fact that I had to remove the spring from my RH Sammy Miller Footrest and lift it to kickstart the bike. What I hate is when the kick start lever flicks back into its 'stored' position at the bottom of the stroke and gets stuck under the footrest mount! with any luck the engine is now running and you have the hand you need to unhook the kickstart lever on the throttle twist grip!

UPB are doing a splined kickstart and ally lever for about £200.... You pay your money.........

Just had the barrel glaze busted and will be putting it together again over the weekend.

If I put a strobe on the engine whilst its running, what should I mark? The 2 yellow dots (1 on the rotating stator and 1 on the static pick up) were set up to align on tdc.

Not sure if I should do the oil return mod while the engine is apart.

Bruce.

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I hadn't considered the possibility of the kickstart flicking into the stored position...something to look forward to - not. I can't imagine how that is happening and will have to dig out the kickstart and look at it to understand how that can happen.

If you didn't glaze bust when you fitted the new rings at the time of the last/recent rebuild then you didn't give the rings a chance to bed in. An interesting if controversial article here:

http://www.mototuneusa.com/break_in_secrets.htm

My sympathies with your problem(s). There are too many variables to pin it down (new carb, new ignition, new build; is the cam timing spot on? can the cam timing be out and not have piston/valve contact? valve clearances (tappets) OK? Valve guides were mentioned? OK? Valves seating sealing OK?).

I've no experience of the PVL system but it is a modification I intend to use so I have researched it somewhat; is the rotor keyed or did you have to accurately position the rotor on the crankshaft at TDC (with degree disc etc)? Is it accurately positioned?

Re checking the ignition timing with a strobe I would recommend this as a first check before you put the primary cover on to make sure that the spark at tickover is occurring around 3deg BTDC and that the ignition timing advances with increasing revs. You say that when the yellow dots are aligned at TDC there are 3 degrees BTDC advance at static; then at tickover under the strobe light the mark on the rotor and the static mark should be aligned or at least quite close together with the mark on the rotor slightly in advance of the static mark if some further advance from static is associated with the rpm at tickover - did you get an advance curve with the ignition kit? As you increase the revs the mark on the rotor should advance with increasing revs up to the maximum advance (is it specified?). If the mark on the rotor appears after the static mark and increasingly so as you increase revs then your ignition is retarding; I don't know if this is physically possible with a PVL system but the Pazon ignition system will retard if wired incorrectly).

Anyway food for thought. If all the engine settings and clearances are correct and the ignition is working as per specification then the probllem goes back to the carb? Are you using fresh fuel?

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  • 3 weeks later...

Esteve,

I can accept the fact that I had to remove the spring from my RH Sammy Miller Footrest and lift it to kickstart the bike. What I hate is when the kick start lever flicks back into its 'stored' position at the bottom of the stroke and gets stuck under the footrest mount! with any luck the engine is now running and you have the hand you need to unhook the kickstart lever on the throttle twist grip!

UPB are doing a splined kickstart and ally lever for about £200.... You pay your money.........

Just had the barrel glaze busted and will be putting it together again over the weekend.

If I put a strobe on the engine whilst its running, what should I mark? The 2 yellow dots (1 on the rotating stator and 1 on the static pick up) were set up to align on tdc.

Not sure if I should do the oil return mod while the engine is apart.

Bruce.

Have you sorted your problems yet? Have cured some similar problems on mine by fitting an Amal carb. The bike now revs out and runs well. Does your bike smoke when hot?

Jack

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Jack,

I just finished putting the engine back in tonight. I had the bore glaze busted and checked ring gaps etc. Everything checked out o.k.

While it was apart I loctited the final drive sprocket nut and took the opportunity to do some minor mods to the cylinder head. (replace thackery washers with solid spacers and blank off top of head nuts)

I haven't found anything obviously wrong but have left the clutch cover off to check the ignition timing with a strobe.

The engine used to smoke a bit on start up and clear after a short while (possibly morgo oil pump and cub valve guides?)

With a bit of luckwill have it running tomorrow night (with yet another new plug fitted). Time will tell. I haven't given up hope yet!

Bruce

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Replaced fluids (apart from clutch/primary drive as cover off to check ignition timing). Put fresh fuel in tank and it started 3rd kick quickly settling down to an even tick over. I have fitted a drilled bush (7 x 8mm holes) into the exhaust in an attempt to quiten it down and possibly produce a bit more back pressure but it is still too noisy to rev the bike up in my shed without the misereable guy next door complaining!

I ran it for a couple of minutes to make sure the oil was circulating o.k. and cure up the new high temp paint on the barrel.

I will sneek out and wizz it up and down the road/path if I get a chance tonight. The problem is trying to get it up to running temperature and rev it up without loading it all up and driving to a practice area.

I have just purchased a Gunson Spark Plug Cleaner (Mini Bead Blaster) to recycle the growing collection of sooty plugs I have. It seems to work o.k. especially when combined with a squirt of 'super clean'

I also picked up 4 plugs from e bay for less than £6 incl postage (I pay almost that each from Halfrauds!).

Fingers crossed!

Bruce.

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