BBK-failure

[ThehardcoreFTW]

Title explains it all.. 

Can`t get her to start, what are common things to go/do wrong with a BBK?
I triple checked valve play and timing, put in a 92 and a 85 jet both without any success. Compression is biiiiig. Didn`t forget to put back a hose/wire and I still have a spark.

What could it be?

[tortoise]

Was the BBK installation running previously?

BBK cylinder diameter?

[ThehardcoreFTW]

Forgot to mention some things, yes.

I installed the BBK just today, rings gapped properly, installed cilinder correct side up and she`s sliding along well. It`s a 72cc 47mm kit from Naraku. Just the jug, didn`t replace the head.

[tortoise]

The challenge is troubleshooting which fuel, spark, timing/compression element is deficient.

Verify engine ground wire is connected.

A momentary run using starting fluid indicates a fuel supply issue.

A performance CDI algorithm may cause hard starting.

Sometimes the flywheel/crankshaft woodruff key will shear which throws off timing.  Insert a mini-screwdriver into the spark plug hole to determine when the piston is at top-dead-center while rotating the cooling fan . . then verify flywheel and camshaft sprocket timing mark alignment.

[ThehardcoreFTW]

Whereabout would the engine ground wire be connected?
I had to make my own markings on the flywheel to mark TDC as the markings on the flywheel were incorrect.

Haven`t got a performance CDI, just a regular (cut) one. Haven`t advanced the timing to my knowledge.

Thanks alot by the way. Will try to start using some starter fluid.

[tortoise]

I had to make my own markings on the flywheel to mark TDC as the markings on the flywheel were incorrect.

This is getting weird . . I'll defer to others!

Typically the flywheel reluctor passes under the pickup/trigger/pulsar coil to ignite a few degrees before top-dead-center.

[ThehardcoreFTW]

Got her to work For a bit

First thing: My F mark doesn`t align with TDC. TDC happens about 10 degrees before F-marking.

Anyway, got her started after doing all sorts of stuff.
Problem being: She`s making a -damn- loud ticking noise coming from the top of the cilinder/bottom of the head, perhaps coming from the valves getting hit by the cilinder? Anyone got an idea what the noise might be? Can`t really narrow it down myself


The ticking noise wasn`t really there the first time I started it, it slowly came on and got louder and louder. Each time after a certain loudness was reached the engine cut out, I`d guess that that this all happens in about a minute.

[blue]

Did you have the right seals. and maybe you need to reset the timeing. and valve adjustment.

[ThehardcoreFTW]

Thanks for helping me! I already fixed it myself though.

One of the things that rattled was the valves, I apparently adjusted them to 0,010mm instead of the suggested (by the owners manual) 0,04mm lol. Fixed them and now the noise is gone
But boy was it a busy week, my plug broke off (was using a  torque wrench, the thing just broke off..) so I had to remove everything to get it out, one of my clutch shoes broke in half, my oil drain plug was stuck and stripped beyond recognition. Got out a saw and some pliers and forced the thing out. Hehe.

She drives nicely, put in 6,5 gram rollers (stock) and cruising about with 8000RPM (a tad high) and usually at about 46mph speedo. Hope that I will get some good miles on her. 90 for jetting, drilled some holes in stock airbox and still got my Leovince exhaust.

Happy new year guys!

[Tseg]

Congrats!  I suppose working through the issues is rewarding... but reinforces why I think I won't modify my (Agility based platform) Super 8 until after the warranty expires in 2 years.  Learning 'shade tree' mechanic capabilities may be best served resurrecting a fairly used up scooter vs. a brand new one.