Replacement Monza 225 piston to replace one with a hole.

[paulnobodyimportant]

Blown a hole in my Monza 225 piston (116 conrod type) that came with the kit back in 2010. I could replace it with the same, but are there better pistons out there now, not that there was nything wrong with the current one.

Reason for hole was me incorrectly jetting. I just had my Monza barrel tuned, coupled with a new Franspeed tourer pipe. Last week it ran too rich from 1/4 to 1/2 on an AV266 with X7 on top clip. Changed atomizer for the leaner AS266 to clean up the bottom end and put X7 on 2nd clip. Was just about to do a plug chop at 1/2 throttle, with intention of adjusting, when it blew. Should really have put on 3rd clip or used a X13, bugger.

Waiting for van

[Boreham]

You can now get the better super Monza pistons.
Also have the richness at 1/4, i run the X13 with the AV266 as a compromise, still get the slight richness at 1/4 to 1/2 but use a 50 slide, it seems a constant issue when running round slide carbs with this kit, tried on several dyno's to iron out but no luck.
Nice Scoot!

[corrado]

Super Monza piston is now standard issue in Monza kits.
AF may have a 70mm Wossner piston to suit 116 rod. They do a Wossner Mugello one, but not sure if they do a TS1 version.

[paulnobodyimportant]

Well, I thought that I had blown a hole in the piston as it was running very hot at the time, due to being too lean and the plug end was grey. But on stripping down this morning, looks like the rings have jumped the peg and scoured the barrel on both sides opposite the transfer ports. Piston has also suffered as can be seen. In effect, its gouged off the lining. I know this is a dumb questions, but I presume that the barrel needs re-plating???? . If so, any recommendations of whome to send it to.

[eden]

looks to me like its just nipped up rather than the rings jumping the peg, has the peg worn down or come out?
another great example of why I prefer cast iron rather than plated barrels.

[HxPaul]

Take it to Firefox Racing in Keighley,they do nicasil plating.They also supply pistons for 2T motorcycles.

[paulnobodyimportant]

Since earlier post, rings had not jumped and pegs still in place. As Eden says, probably a heat seize. Anyway next kit for next rebuild will be Rich' s GT kit
Thanks for heads up Paul, I'll pop over on Monday to see them

[paulnobodyimportant]

onza re-lined barrel back from Langcourts. Actually, it came back some time ago, but other stuff has got in the way of fitting.Anyway, it took 13 days from posting to return, was £139.00 and the finish looks excellent, together with unique foam packing. With the barrel I sent a new Monza super piston and when it all came back, the clearance was 0.003 thou. No base or head gasket and squish at 1.1mm.

This is the Mick Abbey tuned barrel for fast touring. And from the start of this post I foolishly got carried away in the first 3 miles racing my mates, knowing full well that i had not done any plug chops and it was running like a power house and it felt really lean. Of course, ended with a heat seize during the first 3 miles. This was with a leaner AS266 atomizer an X13 on top clip.

Anyway, finally got everything up and running this weekend and took it for a maiden run last night with a richer X2 needle on 2 clip. Runs slightly rich upto 1/2 throttle and really yanks away at above 1/2 throttle. Was going to move it upto 1.5 clips this morning and try it out coming to work, 3 miles away. Instead I have left it safely at 2nd clip and will do plug chops tomorrow evening. And after 150 miles, I'll take it for a dyno as at 200 miles, its run in.

Return Packaging





Cleaned and re-lined barrel






And this is the Oiltek tank that Paul rushed out for me. Must say that its well engineered and a doddle to fix rather than fighting with tank straps.




Top fixing to air scoop




Rear fixing to clamp around rear part of frame



And finally, Franspeed super touring exhaust