No compression, then some compression, then even with no compression on the kick starter it would start and run. Yes, performance was down, but I couldn't believe it would go 110 kph with so little resistance at the kick-starter. I should point out that the decompresser cable to the kick start broke ages ago and I bought the bike without the valve lifter lever or cable. Finally, one night it just gave up on me and it was clear that the head would have to come off.
Endoscope
A while back I bought a USB endoscope to search for electrical wiring sealed up above suspended ceilings without having to rip holes in them. For €16 it came with 5m of cable and worked a treat saving hours of work. It just so happened that it fitted down the plug hole in the head of the Suzuki. I saw a bore a tad glazed but without scratches or signs bad damage. I'm not sure this was much use but it was fun and made me feel clever!Head off then...
So off came the head and it looked fine. Nice healthy deposits for an engine with so many kms on it. Then I popped the valves out and hey presto! |
| Clink! Out fell the valve seat onto the floor |
The valve seat from the left hand exhaust port fell out and rolled across the floor. It must have been loose for a year or more - this was the source of that noise I couldn't trace!
I popped off the cylinder and found the rings were sound enough to show almost no stains from blow-by, so nothing to change there.
The remedy was simple enough - I got another head, cam and rocker box from the same bike through e-bay. €175 got me a very good set of parts, I doubt I could have had the head re-worked for that. Here's the excellent guy I got it from (click).
Straight from the box the inlet and exhaust ports were dry and so I decided to test the valve sealing.
Testing the existing valves
Good practice is to strip out the valves and overhaul the springs, guides, seats and re-grind, but I needed to get the bike back asap for work, so I decided to take a risk. I manually moved each of the valves a dozen or so times then turned the head upside down and filled it with parafin and waited. The idea is that parafin, having no surface tension to speak about is a "searching" liquid. When painted or soaked onto a join, it will find any cracks or non sealing areas and pass through, showing up on the other side like a pee stain on a schoolboy's shorts. When I worked in silo and pressure vessel construction this was a cheap technique used to find cracks in welds, with the parafin on the inside and the outside painted with whitewash. Anyway, after an hour there were no signs of parafin on the otherwise dry inlet or exhaust ports. Good enough, then.
Re-assembly
So, a base gasket cut from my daughter's Barby doll box and a head gasket from Poland (cheap and efficient service - click here) and back together it went uneventfully. I'm really impressed by the design and layout of this engine, it goes together easily and stuff just works! As a final dodge, I fitted the exhaust headers with transparent bathroom sealant - cheap as chips and works really well!The end result is like a new bike. Not bad for a mere €175 + €16 (head gasket) = €191. I bought this bike as a cheapo hack so that I could concentrate on the Triumph and the Velo, but this Suzuki is finding it's place in my heart!
