yam175 Posted December 23, 2019 Report Share Posted December 23, 2019 Right guys my 348 hasn't got a decompressor fitted , should I fit one Quote Link to comment Share on other sites More sharing options...
nh014 Posted December 24, 2019 Report Share Posted December 24, 2019 A decompression valve is used for ease of starting and / or engine braking on downhill runs. In my opinion the 348 does not require any starting assistance, and it is up to you whether or not you desire it for engine braking. In 50+ years of trials riding, I could probably count on one hand the number of times I've seen anyone use one. Quote Link to comment Share on other sites More sharing options...
feetupfun Posted December 24, 2019 Report Share Posted December 24, 2019 I'm old and unfit but can still manage to start my 348 dozens of times during a trial without using a decompressor. Having said that, I find that starting it for a section often takes more effort than riding the section. If it wasn't so hot where I ride, I'd probably leave it running more than I do. They do make a cool noise if you use one for braking. The 348 kickstart mechanism is robust apart from the return stop so there is no need to fit one to protect the mechanism. Quote Link to comment Share on other sites More sharing options...
cleanorbust Posted December 24, 2019 Report Share Posted December 24, 2019 (edited) You should definitely fit one. I have one on my Cota 247 and SWM and wouldn't be without it. I don't use it when starting the bike, it's not intended for that. It comes into its own on steep, greasy descents, allowing you to slow without locking the wheels. Also useful on tracks between sections to warn pedestrians of your approach - a quick blast of the decompressor always turns heads. I use it to stop the motor in normal situations, much kinder than deliberately stalling it. Above all it's a foolproof method of stopping an engine that's revving it's head off after a fall - much more reliable than a kill button. Edited December 24, 2019 by cleanorbust Quote Link to comment Share on other sites More sharing options...
cleanorbust Posted December 24, 2019 Report Share Posted December 24, 2019 (edited) You can get a complete decompressor kit from trialsbits.co.uk or In Motion Trials, or get the cable, decomp unit and lever on eBay for about half the price (sold as being suitable for Royal Enfield but would work OK). Edited December 24, 2019 by cleanorbust Quote Link to comment Share on other sites More sharing options...
yam175 Posted December 24, 2019 Author Report Share Posted December 24, 2019 Ok thanks for the replys , great forum as always Quote Link to comment Share on other sites More sharing options...
section swept Posted December 29, 2019 Report Share Posted December 29, 2019 On 12/24/2019 at 5:14 PM, splatered stu said: this is a Monty....not sure if a decompressor even works on this bike.... On 12/23/2019 at 8:14 PM, yam175 said: Right guys my 348 hasn't got a decompressor fitted , should I fit one Best thing since sliced bread. Allows easy starting, controlled descents and easy engine stopping. No need for a kill switch. Makes a loud chuffing sound when spectators step into your path. Quote Link to comment Share on other sites More sharing options...
turbofurball Posted January 6, 2020 Report Share Posted January 6, 2020 Back to the original point - what's the technique for using a decompressor to aid starting? I ask because since the engine rebuild my 349 takes literally all my weight to kick it in, and my other half can't manage it at all because she's just too little Quote Link to comment Share on other sites More sharing options...
feetupfun Posted January 7, 2020 Report Share Posted January 7, 2020 If I had a decompressor on my 348 I would use it to ease the piston over TDC before giving the kickstart lever the starting stroke Quote Link to comment Share on other sites More sharing options...
woody Posted January 7, 2020 Report Share Posted January 7, 2020 11 hours ago, turbofurball said: Back to the original point - what's the technique for using a decompressor to aid starting? I ask because since the engine rebuild my 349 takes literally all my weight to kick it in, and my other half can't manage it at all because she's just too little Pull the decompressor in and give a couple of kicks on wide open throttle to get a bit of fuel through, then with the decompressor still in kick again but let the decompressor out about 1/3 to 1/2 way through its travel. It's trial and error when to let the decompressor out but after a few attempts you'll get it. I always start my 247 Cota like this as well as my Ossa MARs which can have a habit of slipping on the kickstart ratchet against the compression - using the decompressor takes the strain off and stops that happening 2 Quote Link to comment Share on other sites More sharing options...
turbofurball Posted January 9, 2020 Report Share Posted January 9, 2020 Cool, looks like I could do with one then, lol Quote Link to comment Share on other sites More sharing options...
riffraffretro Posted January 27, 2020 Report Share Posted January 27, 2020 On 1/7/2020 at 8:54 AM, woody said: Pull the decompressor in and give a couple of kicks on wide open throttle to get a bit of fuel through, then with the decompressor still in kick again but let the decompressor out about 1/3 to 1/2 way through its travel. It's trial and error when to let the decompressor out but after a few attempts you'll get it. I always start my 247 Cota like this as well as my Ossa MARs which can have a habit of slipping on the kickstart ratchet against the compression - using the decompressor takes the strain off and stops that happening Yup, this is how I start my 247 fitted with a Venhill decompression kit. It makes the whole process easier IMO, and really does seem to remove the physicality and strain from the starting components. Quote Link to comment Share on other sites More sharing options...
atakin22bed Posted January 27, 2020 Report Share Posted January 27, 2020 Same operating with my 349 mh and my sherpa t 325 ,i always use the decompressor ,it is easyer (sorry for my bad english ) Quote Link to comment Share on other sites More sharing options...
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