Tillotson 225RS Carb Problems

@Sloryd66 15/57. If you get off the corner good you can get the limiter before the finish line. I have a 54.9 on the usual layout on MG reds.

What’s your total weight? I’m 340 with no ballast.

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@Ricky The tilly fills that for me and my son. I can’t afford to take us both two stroke racing. I can afford 206’s and Tilly’s and the tilly is more fun.

When the 206 first came out I was not a fan of it. I used to enjoy the WF and it was a more complete package, which I thought the 206 could’ve been. The WF could have had some improvements also to be fair. If they merged some of the aspects of WF and 206 would be a great engine in my opinion. The pipe on the WF was inconvenient compared to a 206, but it came with the engine. The clutch was no never mind as it came with the engine and was the spec one. To run at a regional or national level you needed a blueprinted engine, but just like 206 I’ve seen engines come out of the box run up front (but isn’t always the case).

@ApexGRT 372 lbs with no ballast. I run the 380 Heavy class with 10 lbs on my kart. I should be in masters at close to 58 years old but that’s another 10 lbs and not enough entries in the 206. I don’t mind mixing it up with the younger guys :wink:

Aside from the carburettor I have come across another issue that causes hard starting on these. As the camshaft in these engines is essentially a regrind, the base circle of the camshaft lobe is cut to to provide the extra lift however this exposes more of the decompressor lever. This bleeds off too much compression especially if you valve lash is set correctly meaning you need to pull the engine over at warp speed to get the thing to fire. Unfortunately there’s no easy fix as the bottom end is sealed.

Also in Australia they have just released a Gen2 upgrade for all 225RS. They replace the head, (perhaps more compression?) and fit a 7500rpm limited coil in place of the 6500. From what I can tell this only seems to be an Australian thing so far?

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@Dan265 we are getting the upgrade now, I have 3 engines in the service center. Any reports on how it runs?

All owners are very impressed with the update, though I can’t say how much faster it is than previous. The engines feel very strong and even seem to start easier however don’t bother trying to hit the new higher rev limiter. The engine simply will not rev past about 7350rpm and is better geared for about 7200rpm max. I’m guessing Tillotson have purposely done this to avoid lengthy limiter periods.

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Awesome, thanks for the info. Looking forward to driving it.

@ApexGRT have you driven the engines yet? Any good comparisons to Gen1 spec, im lead to believe theres been an increase in compression, our engines have been getting pretty hot here.

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No, i am picking them up from the service center tomorrow. I’ll report once I have driven

Prices for carbys in Australia. For reference a genuine Mikuni VM22 or VM26 is $180.