- Joined
- Jun 28, 2009
- Messages
- 2,181
Hi all,
I know the topic has been done to death already, and based on the collective wisdom of this forum (and others) I'm waiting for an XS 650 PCV to arrive from Holland for my '76 T140V.
The bike has the Harris (Gilardoni) Nikasil barrels fitted with low-ish compression pistons (Not sure what...), it has a Spitfire exhaust cam, 32mm Concentrics and the head flowed to suit. There are no air filters and it has standard downpipes and Norton reverse cones fitted. The cams were dialled in to spec and the ignition is an old Boyer, timed at (I think) 36 deg. BTDC FA
I swapped the standard flywheel for a lightened 650 Thruxton mumber.
It runs really well, and is the smoothest Bonnie I've ever had. Always starts first kick and accelerates well...to a point.
The problem I have is that I'd expect it to rev a bit more cleanly than it does; anything above 4,500-5,000 rpm feels like I'm wringing its neck for no good reason. I haven't done a plug chop, but the plug colour looks good.
I don't necessarily want to spend all my time at 6,000rpm, but I would like it to get there occasionally, and with a sense of more to come, if you know what I mean
Would this be symptomatic of poor engine breathing (which is out of the primary, i.e. per the design)?
I've just got hold of a belt primary drive, and I'm considering running the clutch dry. Would running the breather out of the crank timing plug hole be viable, or will it just chuck oil up the pipe?
As I said earlier, I have a PCV on the way, and I'm interested to hear what's the best location to mount it, and the best breather location on the engine.
I have an option on getting the timing cover modded for a breather, but for obvious reasons I don't what to travel this route if I don't have to.
I'd also like to know if there's anything fundamentally wrong with the setup - part of me wants to fit 11:1 pistons, but I rather like the absence of any pinking on modern sh*%e fuels, and the look of the alloy barrels, of course
I know the topic has been done to death already, and based on the collective wisdom of this forum (and others) I'm waiting for an XS 650 PCV to arrive from Holland for my '76 T140V.
The bike has the Harris (Gilardoni) Nikasil barrels fitted with low-ish compression pistons (Not sure what...), it has a Spitfire exhaust cam, 32mm Concentrics and the head flowed to suit. There are no air filters and it has standard downpipes and Norton reverse cones fitted. The cams were dialled in to spec and the ignition is an old Boyer, timed at (I think) 36 deg. BTDC FA
I swapped the standard flywheel for a lightened 650 Thruxton mumber.
It runs really well, and is the smoothest Bonnie I've ever had. Always starts first kick and accelerates well...to a point.
The problem I have is that I'd expect it to rev a bit more cleanly than it does; anything above 4,500-5,000 rpm feels like I'm wringing its neck for no good reason. I haven't done a plug chop, but the plug colour looks good.
I don't necessarily want to spend all my time at 6,000rpm, but I would like it to get there occasionally, and with a sense of more to come, if you know what I mean
Would this be symptomatic of poor engine breathing (which is out of the primary, i.e. per the design)?
I've just got hold of a belt primary drive, and I'm considering running the clutch dry. Would running the breather out of the crank timing plug hole be viable, or will it just chuck oil up the pipe?
As I said earlier, I have a PCV on the way, and I'm interested to hear what's the best location to mount it, and the best breather location on the engine.
I have an option on getting the timing cover modded for a breather, but for obvious reasons I don't what to travel this route if I don't have to.
I'd also like to know if there's anything fundamentally wrong with the setup - part of me wants to fit 11:1 pistons, but I rather like the absence of any pinking on modern sh*%e fuels, and the look of the alloy barrels, of course