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Post by simon998 on Dec 28, 2017 16:26:17 GMT 1
Not sure if this is normal or not.
I recently got my RD125LC mk2 back from the mechanic, it was getting a full gasket set, crank checked, rebore with new mitika piston (0.50), bearings replaced and the wiring tidied up. When I got it back theres a knocking from the right side of the engine, near the bottom. Doesnt go away with the clutch pressed in and gets faster with rev's. It seems the mechanic hasn't fitted the headgasket correctly because I'm getting a lot of blowback and water coming from the rad overflow which never happened before.
Any ideas what this may be?
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Post by yamyzee on Dec 28, 2017 16:41:29 GMT 1
Sounds like......a bad mechanic....theres alot about....sounds like a mullah'd head gasket for a start.these engines are so,so simple to work on,the fact somones buggered it speaks volumes on their mechanical abilities.it takes longer to take the engine out the bike than it does to completely disassemble it into every component.take it back to the muppet who did it, get your money back and do it yourself.....rule No1-if it aint broke,dont fix it....
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Post by simon998 on Dec 29, 2017 11:58:16 GMT 1
He's a good friend, has a RD350LC engine in his Cagiva Mito and various other things with 350lc engines in them so I thought he would know his way around them. I gave him thegasket 'kit', it was a full gasket set and wasn't that expensive. I'm going to order a genuine Yamaha headgasket and swap them out myself.
The barrel was bored out 0.50 and a domed Matika 0.50 piston put in. Due to it being bored out, might that have something to do with the gasket blow by? I was thinking the piston dome might be clipping the head. When I have the head off I'll do a squish test with a bit of playdoh.
It was given to him in the first place because it needed a new crank bearing, we just got the rest of the stuff done as the bike had been sitting for 8 years and needed a little TLC to get it back on the road.
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Post by yamyzee on Dec 29, 2017 12:17:02 GMT 1
You want to use soft solder to measure the squish chap.play doh?  ? thats a new one on me.....use a copper head gasket,cheap and reusable(if annealed).your ace wrench monkey owns a 350lc so does that makes them a top spanner man? I used to see a bird who by her own admission had slept with over 500 bloakes....she was a crap f#ck,means nothing dude.it takes minutes to swap main bearings...and do it properly.are u sure your "works"mechanic bud hasnt put the balance shaft back in out of sync?easy mistake for a novice and will make it run terrible.what about the big end?could be that but if u can hear a noise it will only be a case of minutes before it expires....terminally.... |
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Post by simon998 on Dec 29, 2017 12:57:22 GMT 1
It runs pretty well, starts first kick and holds an idle. Would the balance shaft make it idle or run badly? The knock sounds like metal hitting metal, I'll upload a video later when I'm back home.
It had the big and little ends changed when the crank was out getting checked over by a machine shop.
Admittedly I'm used to working on aircooled 2-stroke kwaks and classic cars, this LC has me a little confused.
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Post by guiri on Dec 30, 2017 19:02:59 GMT 1
of course there should be no strange noises..
have you checked nothing loose like clutch nut or crank end nut.. ive seen all sorts in the past with people rushing the job.
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Post by bertiemollie on Jan 2, 2018 21:37:53 GMT 1
Y.are u sure your "works"mechanic bud hasnt put the balance shaft back in out of sync?easy mistake for a novice and will make it run terrible. How would mis timing the balancer shaft make the engine knock? |
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Post by simon998 on Jan 3, 2018 10:38:36 GMT 1
I still havent got round to uploading the video. I'm going to have to stick it up on youtube.
The sound reminds me of an old engine with loose tappets.
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? thats a new one on me.....use a copper head gasket,cheap and reusable(if annealed).your ace wrench monkey owns a 350lc so does that makes them a top spanner man? I used to see a bird who by her own admission had slept with over 500 bloakes....she was a crap f#ck,means nothing dude.it takes minutes to swap main bearings...and do it properly.are u sure your "works"mechanic bud hasnt put the balance shaft back in out of sync?easy mistake for a novice and will make it run terrible.what about the big end?could be that but if u can hear a noise it will only be a case of minutes before it expires....terminally....
