Mugello 240 ??

[Warkton Tornado No.1]

Another quick question, which I may already have missed comment on... I don't suppose that you're running an advance/retard ignition are you? I ask as this could also explain why the bike is running hot at running in revs in 4th but cools when you down-change and/or 'give it some (an advance/retard ignition would then retard further and run cooler).

Just a thought.

Adam

You are correct, Adam, but the principle of changing down to avoid labouring in any gear will increase the cooling of any fan cooled engine.

However, a retarding ignition should enhance that even further.

My belief is that a good ignition set-up with advance/retard function can be made to work well if the curves are suitable for a Lambretta, but there are many variables besides that, often not taken into consideration. One major factor can be that of 'Operator Error' which is often the hardest for any of us to to admit

If in doubt, cane it with a healthy dose of revs is likely to cause far less damage than attempting to slog along in top

I have built mainly tuned engines in my time, the majority being for racing & with cast iron bores. Such a scenario allows no time for bedding in an engine, the only time being available being any practice laps. Yet, upon strip down, after some hard race miles, the bore & piston can look as good as any other top end that may have been nursed for a 1000 miles. I'm just saying.......

[paul d]

Another quick question, which I may already have missed comment on... I don't suppose that you're running an advance/retard ignition are you? I ask as this could also explain why the bike is running hot at running in revs in 4th but cools when you down-change and/or 'give it some (an advance/retard ignition would then retard further and run cooler).

Just a thought.

Adam

Good point! I've a casatronic fitted to mine and I'd say it definately helps lower the temp along with the extra air from the fan and more fuel when the bike's being reved. Maybe the most important thing when building a 240 is doing a leakdown test. No better man than myself to forget tightening up things, especially with a new build where your laying things out on the table, then handtightening them in place and in my case talking to my brother! Eden knows those engines inside out and is a great help providing carb settings so that particular minefield is sorted. They are a lovely engine. It's worth persevering to get it right.

[corrado]

........ i discounted 2 other 225 kits as they seemed to have problems plating coming off or ring pegs falling out so didn't want to exchange one set of issues for another

I guess that you're referring to the BGMRT225 with the ring peg issue but this was sorted 2 to years ago when BGM switched to Italian made Meteor pistons.

[wintermod65]

the scooter has a bgm flywheel and static cdi ,scootronics dc stator and and regulator , this was due to not being able to get the bgm stator that came with the ignition kit to time up as timing kept wandering also the bgm dc wassel type regulator failed after less than 300 miles ive just bought one of the casa ducati ignition systems from JB tuning as a back up if there are issues with my current set up above and have the sport version on JB's advice . ive found the non adjustable bgm dampers damping action too light to be useful so its fair to say im not feeling the love towards their products so add the problems they had with the bgm cylinder kits i choose too go for the GT 240 , im not looking for some speed demon build just a leisurely tourer
the engine build and resto custom has cost me £20k so getting things right second time is a must .

ps thanks for all info if anyone else has had had similar issues with their GT 240 id like to hear , especially if they cured the issue

[Warkton Tornado No.1]

the scooter has a bgm flywheel and static cdi ,scootronics dc stator and and regulator , this was due to not being able to get the bgm stator that came with the ignition kit to time up as timing kept wandering also the bgm dc wassel type regulator failed after less than 300 miles ive just bought one of the casa ducati ignition systems from JB tuning as a back up if there are issues with my current set up above and have the sport version on JB's advice . ive found the non adjustable bgm dampers damping action too light to be useful so its fair to say im not feeling the love towards their products so add the problems they had with the bgm cylinder kits i choose too go for the GT 240 , im not looking for some speed demon build just a leisurely tourer
the engine build and resto custom has cost me £20k so getting things right second time is a must .

ps thanks for all info if anyone else has had had similar issues with their GT 240 id like to hear , especially if they cured the issue

I can empathise with you.

Ultimately, your decisions from now on need to be the correct choices.

The only way that can be achieved may be somewhat time consuming, but I would suggest that you assume nothing & investigate yourself, to be in complete control.

1) Do a leak test (ALL that is required is an old cycle inner tube cut opposite the valve then persuaded onto the inlet & exhaust manifolds & a cycle pump. Nothing more but a plant sprayer with water & washing up liquid mix helps)

2) Remove the spark plug & measure via the spark plug hole the squish in several places prior to taking the top end off. Check the plug @ the same time.

2-1/2) Inspect the gaskets/packers/gasket faces, head, piston, rings & bore, measuring clearance between the piston/bore clearance & ring end gap. If possible, measure the cylinder head volume.

2-7/8) Report back on here, ideally with photos depicting the state of the piston & bore.

[lozmondo]

Im sure I read somewhere that there had been instances of timing altering on some BGM flywheels for some reason?

worth trying another as youve already mentioned wandering timing ?

[coaster]

I would definately stick with the GT kit personally, I have well over 6k miles on my 240 which only had around 200 miles on it when I rode it to Adria in Italy fully loaded up with camping gear. I was riding with a mate on a GT186 and we were pushing along at between 50-55 mph with a couple of blasts up to 60 or so. The ambient temp got up to mid 30's but I didnt see above 120 f on my SIP speedo but then it spat he plug out on an autobahn and I broker the under plug sensor ring trying to get it back in (it was the sensor that let the plug come loose). For the longest and hotest part of the trip I had no temperature gauge at all and had no overheating issues at all.

My suspission it that you have an air leak and that the jetting has been upped to compensate which would explain your black plug. I exxxperienced that phenomenon on my old TS1 when it started running rough on the way to a rally. The plug was sooty and oily and on the way home it blew a hole in the piston It appears that the head gasket had been leaking for some time

I would also point out how forgiving your GT has been, if youd been running a nicasil lined barrel it would probably have holed the piston rather than just soft siezing. Stick with it, the RT/Mugello/Rapido barrels will all require a reed inlet maniford and might mean frame clearance issues as well as more oportunitied for air leaks.
Colin

[wintermod65]

I would definately stick with the GT kit personally, I have well over 6k miles on my 240 which only had around 200 miles on it when I rode it to Adria in Italy fully loaded up with camping gear. I was riding with a mate on a GT186 and we were pushing along at between 50-55 mph with a couple of blasts up to 60 or so. The ambient temp got up to mid 30's but I didnt see above 120 f on my SIP speedo but then it spat he plug out on an autobahn and I broker the under plug sensor ring trying to get it back in (it was the sensor that let the plug come loose). For the longest and hotest part of the trip I had no temperature gauge at all and had no overheating issues at all.

My suspission it that you have an air leak and that the jetting has been upped to compensate which would explain your black plug. I exxxperienced that phenomenon on my old TS1 when it started running rough on the way to a rally. The plug was sooty and oily and on the way home it blew a hole in the piston It appears that the head gasket had been leaking for some time

I would also point out how forgiving your GT has been, if youd been running a nicasil lined barrel it would probably have holed the piston rather than just soft siezing. Stick with it, the RT/Mugello/Rapido barrels will all require a reed inlet maniford and might mean frame clearance issues as well as more oportunitied for air leaks.
Colin

hi cheers for reply ,
im just down the A140 from you then originally from norwich tho . one of the people who responded earlier seemed to have something similar sounding to my problem . theirs got better with mileage mine hasnt .

the whole scooter is over at the west midlands restorer who built the engine , they are very familiar with GT products so thoufhg it best to ley them have first chance to remedy they issue as might be a warranty issue so could limit cost to me .
have asked for leak test to be carried out , also carb was supplied jetted for the kit but have asked all jet sizes and settings to be compared with rich taylors recommendation .

i'm still not convinced the kit can pull the SX/TV box while im using the bgm clubman v4 , in another post i asked about gearbox choices for this kit most seemed to comeback say the were using LI 150 which surprised me as i was told 4.8:1 sx200 or gp200 using different clutch an front sprocket .

im realising its not going to be cheap potentially cost of kit engine build breakdown repairs and reassemble etc so hoping its something simple but ive learnt its really that way with my scooter !

if we cant resovle the issue not sure where to go with it , not sure if i could return the Kit to dealer for refund full or partial .

if can sort it il post what issue was

[Scooterdude]

Can’t remember when exactly but maybe a year or so ago there was a recall on these kits as the piston to bore clearance was to tight, wonder if you’ve got one that somehow slipped through the net? Worth checking.

[coaster]

i'm still not convinced the kit can pull the SX/TV box while im using the bgm clubman v4 , in another post i asked about gearbox choices for this kit most seemed to comeback say the were using LI 150 which surprised me as i was told 4.8:1 sx200 or gp200 using different clutch an front sprocket

I am also using a BGM exhaust (Mk3) scootronics stator and Li150 bow with 17/46 sprockets giving 4.8 final ratio although I think it would pull 4.6 tbh.

I recent;ly fitted an egt to the BGM manifold and have noticed allarmingly high temps (700 degrees ) but at the same time the cht has been normal so I figure it MIGHT be due to the BGM tail pipe being on the small side. EGTs are fickle though so I'm not worrying about that reading tgh