History:
Bike was an ex Formula Extreme racebike last raced in 2010 with a apparently refreshed engine for the next season. I bought the bike in 2011 & have only really been using it again the past 18 months – it is now fully converted back to a road bike. The engine had $7000 of work done to it (unknown besides the fact it was blueprinted) & no doubt the valve clearance were set on the tight side for best power.
Have just checked my valves clearances & found them to be either at the limit of their allowances (on the tight side) or beyond the allowance (again on the tight side) – check out my results below.
Intake Valve Service Tolerances: 0.08 - 0.18mm
Exhaust Valve Service Tolerances: 0.18 - 0.28mm
I really only use the bike for commuting this winter with max sustained speeds of 60mph (100kph) however need to sort it out in any case. Can anyone tell me if they has been any likely damage suffered from the exhaust valves being too tight? The engine has been under very light load the last 10,000 miles so not too much gases or heat being rejected by it & the compression is largely ok except for 1 cylinder being a little lower that the others but only by 5% (I will recheck the compression after I put the bike back together after the shim measuring.)
All the plugs were looking on the lean side with plugs 1 & 4 looking slightly whiter that the centre pair - makes sense if the exhaust valves were too tight on this side too.
Cylinder 1
Cylinder 2
Cylinder 3
Cylinder 4
Also can anyone recommend a place to get shims cheap seeing as I will be needing to do all 16 of them by the looks of things!
Bike was an ex Formula Extreme racebike last raced in 2010 with a apparently refreshed engine for the next season. I bought the bike in 2011 & have only really been using it again the past 18 months – it is now fully converted back to a road bike. The engine had $7000 of work done to it (unknown besides the fact it was blueprinted) & no doubt the valve clearance were set on the tight side for best power.
Have just checked my valves clearances & found them to be either at the limit of their allowances (on the tight side) or beyond the allowance (again on the tight side) – check out my results below.
Intake Valve Service Tolerances: 0.08 - 0.18mm
Exhaust Valve Service Tolerances: 0.18 - 0.28mm
I really only use the bike for commuting this winter with max sustained speeds of 60mph (100kph) however need to sort it out in any case. Can anyone tell me if they has been any likely damage suffered from the exhaust valves being too tight? The engine has been under very light load the last 10,000 miles so not too much gases or heat being rejected by it & the compression is largely ok except for 1 cylinder being a little lower that the others but only by 5% (I will recheck the compression after I put the bike back together after the shim measuring.)
All the plugs were looking on the lean side with plugs 1 & 4 looking slightly whiter that the centre pair - makes sense if the exhaust valves were too tight on this side too.
Cylinder 1
Cylinder 2
Cylinder 3
Cylinder 4
Also can anyone recommend a place to get shims cheap seeing as I will be needing to do all 16 of them by the looks of things!