Andyb1987 Posted March 15, 2018 Report Share Posted March 15, 2018 I have a montwas 315r 1999 2 stroke I'm getting a slight rattle/knock when I close the throttle (on run down) there are 4 different size base gaskets 0.3,0.5,0.75,1.0 I currently have a 0.5 on could this be the cause I'm no expert when it comes to 2 strokes any advice welcome Quote Link to comment Share on other sites More sharing options...
copemech Posted March 16, 2018 Report Share Posted March 16, 2018 A larger pilot jet in the Carby can help or cure a throttle chop ping. Is this a Dellorto? What is current jetting? Quote Link to comment Share on other sites More sharing options...
section swept Posted March 16, 2018 Report Share Posted March 16, 2018 15 hours ago, Andyb1987 said: I have a montwas 315r 1999 2 stroke I'm getting a slight rattle/knock when I close the throttle (on run down) there are 4 different size base gaskets 0.3,0.5,0.75,1.0 I currently have a 0.5 on could this be the cause I'm no expert when it comes to 2 strokes any advice welcome Was this noise evident before changing base gasket? Have you had bike long? What oil/fuel mix ratio are you using? Its best on a two stroke to not close the throttle fully on ‘run down’ as this could cause the piston to nip up due to lack of oil, momentarily is ok but on downhill you should keep the throttle slightly open. What you may be hearing is the piston slapping the cylinder bore as there is no stabilising power stroke, so rather than the piston doing work it is being driven by the transmission. All this is fine and dandy but without hearing the engine my advise is purely based on conjecture. ?? 1 Quote Link to comment Share on other sites More sharing options...
section swept Posted March 16, 2018 Report Share Posted March 16, 2018 Just another thought, you aren’t confusing the drive chain rattling against the frame etc. ?? Quote Link to comment Share on other sites More sharing options...
Andyb1987 Posted March 17, 2018 Author Report Share Posted March 17, 2018 Thanks for the replies everyone no it's not the chain on the frame. I've had the bike six month or so honestly don't know which jets are in the carb I did strip and clean it when I got it I pulled the head off for an inspection and refitted with new gaskets I measured a part of the base gasket which had not been flattened using a caliper gauge which came out at .45 to which I assume is a 0.5 gasket I've been searching for weeks on the internet and read a post regarding base gaskets but that was on ktm 2stroke motox not trials so not sure if it relates or not I am a total novice when I comes to two strokes. I changed the exhaust manifold gasket when I put back together but the header pipe doesnt sit fully in the recess could this be the problem. Also changed all fluids wheel bearings linkage bearings Quote Link to comment Share on other sites More sharing options...
Andyb1987 Posted March 23, 2018 Author Report Share Posted March 23, 2018 On 16/03/2018 at 6:13 AM, copemech said: A larger pilot jet in the Carby can help or cure a throttle chop ping. Is this a Dellorto? What is current jetting? 120 main 46 pilot assuming the main is the one the keeps the bowl on Quote Link to comment Share on other sites More sharing options...
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