Join Date: Jun 2006
Location: Melbourne, Australia (formerly Ireland)
Motorcycle: GSXR 1000 K6 & K8
GSXR1000 K8 Top End Rebuild - First time attempt advice required
Need to do a top end rebuild on my ex-racebike GSXR1000 K8 which has been restored to commuter & weekend fun duty only. I suspect an exhaust valve is leaking in cylinder 1 as the compression is 2Bar lower than the others, the engine misfires/backfires at partial throttle, it idles unevenly, the exhaust is partially sucking from 1500 - 4000RPM & Cylinder 1 does not fire evenly like the others when I spray ether directly into the inlet manifold. The bike is a pig to ride at low speed as the throttle response is so jerky & uneven but it feels ok above 4000RPM with a bit more throttle.
I will inspect my current head when removed to see what the issue is - can remove the valves, test for leakage by pooling petrol in the combustion bowl, etc.. Hopefully I don't need to replace any valve seats & just need to replace 1 or mare dodgy valve (I have purchased a valve lapping kit & 'Persian Blue' marker to check the valve sealing depth & concentricity). I don’t know what thickness the current head gasket is but is likely to be thinner as was a race bike - need advice on what I should replace with for the road when using only premium gas/petrol.
Am an mech/elec engineer & accomplished home mechanic with semi-pro garage tools available ( I can get pretty much anything I need) - I have no fear about doing the actual work once I have the parts/tools available to me.
Please can experienced guys advise on the following key questions
- Head gasket size/thickness (stock bore) & where to buy? Is it safe to use a thinner gasket (95 & 98 RON widely available here)
- Can the job be done by leaving engine in the frame? (or at least leaving the rear part bolted in & pivot the top forward into the front wheel space)
- What special tools do I need if any (Have torque wrenches, digital callipers, feeler gauges, compressed air & power tools, etc.)
- What else should I check on old engine before rebuilding (cam wear, timing chain, cam chain tensioner etc.)
- What consumables do I need to replace (besides head gasket - head bolts, other gaskets, O-rings, etc.)
- What should I check on the donor head before fitment (Valve clearances, compression check/leakdown, leaking valves at seats, warping requiring, head shave, etc.)
All help & guidance appreciated fellas.
Last edited by King Kenny; 09-08-2017 at 02:34 AM.