Rae

For anyone curious in the future: yes, I do need the head cover to fit the head insert for 14+ Racing. Not sure on the Pro

Hello, Wondering if the S3 low compression head insert works on the 280 Racing trim. Just don't want to have to purchase the S3 head cover if it's not necessary. Thanks! Edit: forgot to add model year: 2021

i can't say for sure since I wasn't the one who started that comment, but I do think that you're practically lugging the engine to a stop which isn't good either. also, i believe I fixed my issue by increasing the idle. thank you all for your help

i also just remembered that the previous owner used a heat range 8 plug when Honda recommends 6. far too cold with the 8 plug. i've put in the stock 6 plug, put some fuel injector/valve cleaner in the fuel and ran it for about 10 minutes. it was sputtering for a little bit but it seems to have eventually smoothed out. i will continue using the cleaner for the rest of this tank and the next few and see how it goes... I'm not Jimmy but it's my belief that the only thing that hurts when you stall a bike is your pride 😆

just checked for any spanner marks but there are none on the head or around the cylinder. the fan seems to run fine when i'm warming it up. no issues with the fan but the coil may need to be swapped. i noticed while riding for a bit today that when it backfires, it almost feels like letting go of the clutch for a split second and back on. could be a fuel problem... although the fuel is new. maybe it just doesnt like non ethanol gas? i always let it warm up until the fan kicks on. i do not rev the bike when warming up. no start stop riding, i usually just keep it running whenever i walk away this is a rather interesting situation... maybe i need to check the valves again...

That’s good to know! My idle is set at 1850 when warm… bought a tach/hour meter just to check. It idles and sounds similarly to a 4rt owner on YouTube so I believe it’s idling fine. I didn’t know that all 4 strokes backfires when in neutral. I did notice that it backfires less when in gear and I rev it up but still backfires. I checked it when on the stand. Maybe it’s different if I’m riding and revving… I’ll check that later. ive also checked the throttle body to make sure that the restrictor is removed. maybe I’m chasing my own tail here. May not even be an issue. It’s just that the plug continues to foul and I can’t for the life me figure out why

Hello all, ive got a new to me 2018 Montesa 4rt with a backfiring problem. it tends to only backfire (or after fire) when I’m holding revs at a higher rpm than idle. It tends to continuously foul plugs as well. I’ve gone through 3 plugs so far and after every warm up, it’ll foul a plug. The plug also slightly smells of gas. It starts 2nd kick when cold, but starts 1st kick when warm. things I’ve checked so far: 1. Cleaned air filter and removed excess oil 2. new spark plug (cr 6) 3. Valve clearances set per manual 4. resealed and tightened exhaust connections 5. new fuel (93 octane non ethanol) Other things I’ve thought but haven’t tried: new coil different gas with 10% ethanol hotter plug (it’s 30 degrees f recently) could anyone guide me in the right direction? Not sure if the idling sounds right either…

Thanks for the info! Certainly gives me hope into my abyssal future in trials I'll continue on with just having a finger on the clutch and front brake only when necessary

When trying to zap or bring the front end up, I have a hard time giving throttle while having a finger on my front brakes. I am rather new to trials and needing a bit of guidance on whether I should be resting at least one finger on my brakes/clutch lever at all times or not. I am able to clear sections easily when I do not hold my finger on my front brakes (especially because I can manage the throttle a lot easier) but when it comes to me improving, I don't want to have bad habits which will prevent me from getting into harder sections. I practiced holding my finger on my front brakes while giving throttle and it continuously ends up with some whiskey throttle and the kill switch lanyard comes off 😁

thanks for the suggestion, i just checked the bolts between the pipe and exhaust port along with a clamp between the muffler and pipe. the latter was a little loose so i tightened it up. i'll check for any odd sounds tomorrow.

yep, it's a rather high pitched sound as soon as the throttle is closed and the revs drop back down to idle. sometimes it'll happen in idle too but i'm glad it's normal behavior

My 2018 Montesa Cota 4rt seems to have a chirping sound coming from the exhaust. I’m not sure if there is something wrong with the bike or if this is normal. Does anyone know if my bike sounds like it’s running good and any ideas on the chirping? Sound available below. few things I’ve done: changed the spark plug to OEM (previous owner had a very cold plug) and that reduced the chirping but not fully Cleaned and oiled air filter (still makes sound even with air filter out, so it’s not over oiled or anything) regular oil change and oil filter change replaced gearbox oil with elf htx740 Give it a listen here: https://youtube.com/shorts/7mN_C2LJOzk?feature=share