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Yeah, that's what I thought. Weird they used a short spark plug, makes no sense. I think I'll try to make it run with the stock Amal, if possible, with a loooong transparent hose carrying the premix to the bowl and with the end vented to atmosphere... so I can rule the carb out. But as I said, I'm afraid it's an electrical issue.

That could cause hard starting (and poor running in general). But probably not bogging after 1 – 5 minutes.

Thanks! I was a guitar builder and my customers base was always in the US, so I had time to practice 😂 I noticed the spark plugs fitted on the head have a SHORT threaded portion... I'd say 12mm or so, while in pure theory they should be the long version. Could it be the cause of the problem? I doubt it, but you never know.

The hard starting may or may not be related to the bogging. When I'm trying to find thermal problems with electrical components, I use a heat gun https://en.wikipedia.org/wiki/Heat_gun and/or freeze spray https://en.wikipedia.org/wiki/Freeze_spray Freeze spray is fairly expensive. A lower-cost alternative is a compressed air duster (like for computer keyboards) turned upside down. BTW, I must complement your English, it's very good!

I checked the impedance of both my Motoplat stators and it's about 32ohm (31.8). I'm having this weird issue... bike hard to start, then starts, works for a short period (1-5 minutes) and then starts bogging. It's not fuel-related as there's still premix in the bowl when it dies.

Hi Sam do you still have the Fantics ?

I got my Majesty to steer better by moving the bottom clamps and rewelding :

How lucky we are to have the internet and people who know how to use it. konrad is the man for the job every time. Hope it does the job.

Searching Motoplat 9635406, I found this: https://www.ebay.co.uk/itm/255086002289

I live in uk it’s a gas gas 250 number on engine is 327 and motor plat cdi 9635406 I believe it’s a 93 model could I put a different cdi unit on this or have I got to use the same one

@nhuskys Brilliant. Thanks , that's what I have been waiting for.

I enlarged the steering stem hole in a spare top triple clamp and made an eccentric to fit in the hole to move the top triple clamp forwards slightly. I did not aim for parallel. I can't remember the concentric dimension for the eccentric piece offhand but there is still some angular offset. From memory, the goal was to move the front wheel axle rearwards by 5mm. To get the fork tube holes to line up again, I twisted the bottom triple clamp then twisted the upper triple clamp. What I wanted was for my KT250 to steer like a TY250 and it now does exactly that.

Ah OK. I guess it's a bit different here where there are lots of derelict TY250s lying around. Plenty of TY250 parts in the US as well.

Feetupfun, The goal was to have a more stable 34mm front end, less deflection in rock beds that I have noticed with the 28mm on the 175

All information is needed , actual bike model etc what is it Ducati system or Motoplat ?.Where are you USA , UK etc ?

Hi Feetup, how did you modify the trees to get paralel offset ?

Looking for a cdi module as I broke the pins off mine I try was motorplat the last numbers were 406 bike used to run but now it’s not running could do with some help

I'm glad you mentioned using the KT triple clamps as well as the forks. Did you realise that KT triple clamps are a lot further apart than TY triple clamps, so there will probably be some work involved with fitting the KT triple clamps into a TY frame. I haven't tried this to know what's required but at least the angular offsets of the KT fork tube holes will be incorrect if the KT triple clamps are moved closer together. The other stumbling block there is that the TY steering stem may not fit the stem holes in the KT triple clamps. As for attaching the TY brake link, it would be pretty easy to make a clamp that fits around the left side KT fork bottom for the TY brake link to attach to. No idea what spacers might be needed for TY wheel in KT forks with KT triple clamps. If you have a TY wheel or TY forks in their triple clamps and some KT forks in their triple clamps, you can measure them up and compare. Also have a think about where the KT fork tubes will end up at full lock relative to the TY fuel tank. Unless you limit the steering angle, I suspect they might hit the TY tank. This is because the KT triple clamps are designed for leading axle forks which usually positions the fork tubes more rearwards when straight ahead and closer to the midline of the bike at full lock, compared with (in-line axle forks) TY triple clamps. For what it's worth, the standard angular offset for both sets of triple clamps is the same (1.5 degrees). I modified my KT triple clamps to reduce the angular offset to achieve the same trail dimension as a TY (to make my KT steer better). You could do something similar to a set of TY triple clamps to achieve the same trail as a KT250 with a lot less trouble than doing a front end swap. However, I'm only guessing that this is what you are trying to achieve. What are you trying to achieve?

I am seeking a lighting and electrical wiring kit stripped from any of the ST250 through 300 series. Lights, taillights, horn, regulators wiring harness all welcome. I'll pay top dollar in the USA. Don't ask why....I just need it to get licensed...then off it comes again. Lemme know Phil

FANTASTIC web site link on the OSSA. Simply FANTASTIC!

Not suggesting 2mm more base gasket. Recommending 2mm (or any other value your experiments show to be helpful) total squish clearance. The squish may already be on the order of 1.2mm. Yes, it will change the port timing, but I have not seen that small change cause negative side effects. If anything, it makes the bike slightly easier to kick. It's also easily reversible. The Sherco uses o-ring seals for the head/cylinder interface, which I would leave alone. Machining the head is another, less reversible, route. Increasing the combustion chamber's “blend radius” is another way to soften the hit. I touch on that here: https://www.ossa-efi.com/home/engine/heads Also, a bit on reeds here: https://www.ossa-efi.com/home/engine/reed-valves I'm going to retract my G2 idea based on RonH's experience. I now see it's intended to be a blend of the slow and fast rates. Whereas Ron's idea for a “slower than slow” tube is more what you need.

I like your suggestion with the cam. Thank you for your help.

Adding 2mm to base gaskets will also change the port timing slightly, whereas increasing the head gasket will not. Is it your recommendation to lower compression AND change port timing by using a base gasket, or just to lower compression by using a head gasket?

Two cheap, easy, reversible changes: Retard ignition timing. Increase squish clearance to ~2mm via additional base gaskets. Additionally, if you are good with the clutch, a flywheel weigh can help slow things down. A company called G2 makes a cammed throttle tube called the Tamer: https://www.g2ergo.com/shop/g2-trials-throttle-tube-progressive-rate-sherco/