shambles1980 Posted September 28, 2012 Share Posted September 28, 2012 ok, bear with me on this one. im in the middle of a house move and the bike is about 3 miles away. so i wont be able to tell you things about it untill ive been up there and done stuff.. any way heres the deal. picked up an rsx100 the other day, and it is in a bit of a dire straight cosmetically its not to bad. needs a new indecator lens. and had apparantly passed its last mot before the issue started.. Now all i know is that it starts but has no power. and the previous owner thought iot could be carb related, but he is no expert. it has had a new piston and not that long ago "i assume to try and rectify the issue" and if they replaced the piston im sure they would have noticed any gouges in the head. But i will check for some any way. I think its likley to be a crank seal or something thats blown, so i have bought a complete gasket set and complete engine oil seals set. it could be bearings i guess but as i havent started the bike yet i cant listen out for any tell tale sounds.. so basically id like a list of things to check. Im presuming that i should start off at the exhaust and work my way up to more serious areas such as the head. any way help apretiated. i havent rebuilt/striped a 2 stroke engine since the 90's so glad of any help offerd Link to comment Share on other sites More sharing options...
Moderator Cynic Posted September 28, 2012 Moderator Share Posted September 28, 2012 Seeing as you have a full gasket set get the bearings too and tear it down. You know it runs at present so a rebuild with seals and gaskets will solve a lot of the confusion. If you stretch to a carb overhaul kit you should be laughing. The only pieces of kit i would advise over a regular kit of sockets and spanners would be an impact driver, a heat gun and a flywheel puller. Good luck with it. Link to comment Share on other sites More sharing options...
shambles1980 Posted September 28, 2012 Author Share Posted September 28, 2012 i went up there today. and the spark plug has been removed from the cylinder head. "had no tools to replace it with me" so i did the old jam my finger in the hole and see if there is any pressure test.. Seemed ok.. Kicked it in to 1st. and pushed and even without the plug in you could tell it was in gear... But i aint so sure that im able to select 2nd or 3rd excetera.. It may just be the gearing and the fact that it had no spark plug in there, but i swear that bike felt like it was in neutral in every gear expet for 1st. obviously i will be going back up there tomorrow with my tools. and il try it again with the spark plug in. hopefully with the spark plug in il get some resistance when i try to push it in gear. any way Im assuming it was just easy to push due to the piston being able to travel easily due to missing the spark plug. But im wondering if the inlet reeds can go and cause issues like this? I should probably just strip it down and get it on the bench before i try to diagnose whats up with it. but given that i just got the bike and I want to work on it but the dumb thing is miles away All i have is trying to think what could be the issue. Link to comment Share on other sites More sharing options...
Canny lad Posted September 29, 2012 Share Posted September 29, 2012 before you start assuming things start with exacts... get a plug in there and make sure its in neutral... the RXS is not a high compression engine anyway and can be startted by using your hand to press the kicker.. it does take abit of a push mind but can be done.. if it starts then get it running and see for sure what it is like...for me it makes no sense that its ok in 1st and not the rest of the gears... once you know exactly whats what you can go from there... the RXS engines are pretty bomb proof as far as 2T motors go... mine is on original piston and rings and 29,000 on the clock.. report back when you have checked what it does and doesnt do Link to comment Share on other sites More sharing options...
shambles1980 Posted September 30, 2012 Author Share Posted September 30, 2012 ok. was up there again today. Found out why the spakplug was only hand tight when i got the bike.. Seems some one had over done the tightening. and the thread is knackerd. have a new cylinder head on the way now. any way tI found all the gears now and seem fine. I assume that this lack of power issue the bike has will be due to loss of pressure from the cylinder head. You can hear all the pressure hiss out arround the plug when you crank it by hand. Hopefully that will be an easy fix then. Il just clean out the cylinder and then replace the head and with any luck that will have it fixed. As for the old head. Im wondering if there are any over sized spark plugs i can get, then i could use a tap and die set on the hole and use a bigger spark plug. seems a shame to waste it due to something like a few bad threads Link to comment Share on other sites More sharing options...
Moderator Cynic Posted September 30, 2012 Moderator Share Posted September 30, 2012 Any good engineering company will be able to fix the head. Eithe helicoil or welding the hole and then re drilling and tapping. It certainly isnt junk. Link to comment Share on other sites More sharing options...
shambles1980 Posted September 30, 2012 Author Share Posted September 30, 2012 dont have any good places around here in rural wales lol.. been looking at heli-coils. wonder if they are viable. im still not certain that i could drill the hole out straight enough. but as i do have a new cylinder head on the way it should be ok. seeing as i have all the bearings seals and gaskets on the way im still going for a full strip down clean and rebuild. Im hoping that will give me better preformance and make it more economical to run. had a crazy idea to JB weld a plug in place given that its a low pressure engine. see how that holds whilst i wait for the new head Link to comment Share on other sites More sharing options...
pyro plim Posted September 30, 2012 Share Posted September 30, 2012 I would wait for new head mate and take the old one to be helicoiled at leisure.If you look up the the exhaust port you will see its square .If you grind it out to a round shape it will fly then but dont take any off the barrel side or alter the port inside or you will wreck it.. Link to comment Share on other sites More sharing options...
shambles1980 Posted September 30, 2012 Author Share Posted September 30, 2012 i just dont like sitting around doing nothing lol.. Im used to having what i need at hand. and then being able to do it.. lol if the bike was down here id probably have the engine in the house with me now nice cup of coffee and engine in bits getting all cleaned up. I had to rebuild an ar125 i bought in boxes about 13 years ago "some one had striped it down and just decided it was to much work" turned out to be missing a woodruff key, and i couldnt figure out where the disk valve should be in relation to the piston, but apart from that it all went fine. sold it to a friend who replaced the woodruff key and set the disk vale correctly and it ran like a charm. Link to comment Share on other sites More sharing options...
pyro plim Posted September 30, 2012 Share Posted September 30, 2012 AH the old having to wait problem lol.Its hard i know i just bought a yg1 and want to have it on the road last week .But its going to be a long build this one.This one is the rotary valve 80cc engine but i will try the engine first see how it runs before any pulling it bits as it is in very good condition and it has a very strange gear shift mecanism..I should think it will need crank seals with been stood .Happy days lol Link to comment Share on other sites More sharing options...
shambles1980 Posted October 3, 2012 Author Share Posted October 3, 2012 still wating and its frustrating lol. cylinder head still has not arrived. and whats worse "to me at least" i orderd new set of oil seals. and a sprocket carrier bearing from the same company. the sprocket carrier bearing arrived yesterday. (was dispatched on the 1st) but the oil seals were dispached on the 29th and still have not arrived. and i havent been able to get them to reply to emails.. the head wont be here till the 5th!! (thats forever away) also i just spotted a cb125 for sale for cheap. But the wife wont let me buy it because im still working on this bike.. any one know a good way to convince a wife that i need 2 bikes? Link to comment Share on other sites More sharing options...
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