bigbird2 Posted September 26, 2013 Report Share Posted September 26, 2013 My 2009 300 4t sounds BAD. I haven't done any investigation yet to determine what is wrong but it is making knocking sounds so probably NOT trivial. Does anyone have recommendations on repair service available locally OR that I could ship the motor to (assuming it is a serious problem)? I live in Frederick Maryland. There is a local dealer but he has never been inside one of these 4t engines. Thanks for any help! Quote Link to comment Share on other sites More sharing options...
billyt Posted September 26, 2013 Report Share Posted September 26, 2013 The valve gap needs to be checked. A bitch to get to but easy to do once exposed. Quote Link to comment Share on other sites More sharing options...
bilks Posted September 26, 2013 Report Share Posted September 26, 2013 (edited) Engine Manual,Try this, might help. Just click on the link then just enter code then should download, http://www.freefileh.../2009-2010evo4t Edited September 26, 2013 by bilks Quote Link to comment Share on other sites More sharing options...
wright4d Posted September 27, 2013 Report Share Posted September 27, 2013 My 2010 300 4T was making a bad knocking sound on idle and low revs it turned out to be the spring on the de-compressor weight that had failed. If you look in the manual it shows a small weight on the cam shaft. You can download a 4t engine service manual from American Beta and on page 64 it shows the weight and spring. Not saying this is your actual problem but this failed on mine and might be worth considering. Good luck Manual here in support section. http://www.americanbeta.com/ Quote Link to comment Share on other sites More sharing options...
zerorev3rev4 Posted September 27, 2013 Report Share Posted September 27, 2013 its no differnt to most 4t engines could be timing chain or if had a lot of use valve guides could be worn Quote Link to comment Share on other sites More sharing options...
jimg Posted October 1, 2013 Report Share Posted October 1, 2013 (edited) First, check your cam chain tension adjuster. The spring on my bike wasn't applying enough spring compression to the self-adjusting unit, so I ended up finding a similar spring (acutally a little heavier) and soldered about 3 coil lengths to the existing spring. The extra spring compression force made the self adjuster click out a notch creating more force against the cam chain guide. If that doesn't work it is likely the decompression tension spring, which will cause a BAD loud knocking. This happened to my bike as well. It was hard to determine where the noise was coming from when the bike was running, but after taking the engine apart and hours upon hours of diagnosis it was the spring. Low cost fix to do yourself, but will still take several hours to replace the spring. Edited October 1, 2013 by jimg 1 Quote Link to comment Share on other sites More sharing options...
bigbird2 Posted October 8, 2013 Author Report Share Posted October 8, 2013 WOW! I'm impressed by the responses! Thanks Folks! I got sidetracked for a few days with a problem with another bike but now I'm gonna try the Beta. Hopefully my problem is the spring for the decompressor weight. The noise appeared suddenly and sounds BAD. I had to ride the bike for a mile or so with the noise and tried not to rev it too much. From looking at the manual - I THINK I can replace the spring without getting into the bottom of the engine? Is it possible to get the cam out and back in without messing with the water pump or even removing the bottom part of the cylinder head? It seems like I MIGHT be able to just take the top of the cylinder head off then slip the bearings off the cam then get the cam out to replace the decompressor spring. If I marked where the cam sprocket teeth mate to chain, MAYBE I could reassemble it back the same way to avoid having to do the locking of the crank at TDC routine? IF this plan is workable and it is the spring - I don't see any parts other than the spring that I'd need - unless it is likely that the weight is damaged? This assumes I could reuse the O-rings that are on the little covers one uses to check and adjust the valves, etc. I'd appreciate any guidance you can offer. I'm not too cheap to by any parts you think I'll need. Just trying to keep it as simple as possible. I'm reasonably competent at this kind of stuff BUT sure don't want to get into it any deeper than necessary. THANKS AGAIN! Quote Link to comment Share on other sites More sharing options...
nzralphy Posted October 8, 2013 Report Share Posted October 8, 2013 The orings are likely to be ok. If you take the head off you'll likely need a head gasket. If I remember you can take the cam out without removing the head. Put the piston at TDC and mark the chain and cam sprocket with a dot of white paint where they line up with the head before you start. It makes easy assembly. Quote Link to comment Share on other sites More sharing options...
bigbird2 Posted October 8, 2013 Author Report Share Posted October 8, 2013 You guys are great! Responses from England Scotland NZ Michigan USA! Keep them coming as I need all the help I can get! Quote Link to comment Share on other sites More sharing options...
tman427 Posted October 8, 2013 Report Share Posted October 8, 2013 WOW! I'm impressed by the responses! Thanks Folks! I got sidetracked for a few days with a problem with another bike but now I'm gonna try the Beta. Hopefully my problem is the spring for the decompressor weight. The noise appeared suddenly and sounds BAD. I had to ride the bike for a mile or so with the noise and tried not to rev it too much. From looking at the manual - I THINK I can replace the spring without getting into the bottom of the engine? Is it possible to get the cam out and back in without messing with the water pump or even removing the bottom part of the cylinder head? It seems like I MIGHT be able to just take the top of the cylinder head off then slip the bearings off the cam then get the cam out to replace the decompressor spring. If I marked where the cam sprocket teeth mate to chain, MAYBE I could reassemble it back the same way to avoid having to do the locking of the crank at TDC routine? IF this plan is workable and it is the spring - I don't see any parts other than the spring that I'd need - unless it is likely that the weight is damaged? This assumes I could reuse the O-rings that are on the little covers one uses to check and adjust the valves, etc. I'd appreciate any guidance you can offer. I'm not too cheap to by any parts you think I'll need. Just trying to keep it as simple as possible. I'm reasonably competent at this kind of stuff BUT sure don't want to get into it any deeper than necessary. THANKS AGAIN! Knights Cycle up in Massachusetts did some valve and head work for me with great results. The only other dealer close to you would be:Dave Diehl at 570-437-2487 Or by email at dd.teambeta@live.com He maybe able to help. Quote Link to comment Share on other sites More sharing options...
jimg Posted October 10, 2013 Report Share Posted October 10, 2013 (edited) Always start with the easy stuff first...before you replace the decompression spring, I highly recommend start with checking the cam chain tension adjuster as I mentioned in my above post. Check for any wear on the teeth and I'd put a new sping in or add an extinsion to it as I described above. When you put the adjuster unit back in, use a small screwdriver and press on the adjuster until it stops clicking. Start the bike...If that's not it, then change out the decompression spring. Set the bike at TDC per the service manual...it's very easy and well worth the extra 10 minutes (you can avoid draining the engine oil if you set the bike at a 45 deg angle when setting TDC). I ended up dropping the front of the engine down by removing the front skid plate bolts (the rad will come with it without having to remove the hoses). I couldn't get the top head piece off without doing so. You'll need to remove the cam chain tensioner again to loosen the cam chain. Then you will be able to replace the spring by tiltling the cam and removing the chain (no water pump removal needed). Make sure the chain doesn't fall...I used a screwdriver to hold it up. Putting that little spring in there is a bit tricky, so make sure you follow the installation instructions per the service manual exactly....an extra wind on the spring won't work. The top head doesn't have a gasket, so use high temp RTV. Tighten all head bolts per instructions....important. Edited October 10, 2013 by jimg 1 Quote Link to comment Share on other sites More sharing options...
bigbird2 Posted October 12, 2013 Author Report Share Posted October 12, 2013 jimg - Thanks for the reply. I will do as you suggest before going after the spring replacement. Maybe I'll be really lucky? The only reason I didn't jump on it the first time is that I ASSUMED that since my noise was loud and sudden that it was more likely the spring. BUT your idea is certainly worth a shot and basically free! Thanks Again. Quote Link to comment Share on other sites More sharing options...
bigbird2 Posted October 21, 2013 Author Report Share Posted October 21, 2013 Well I tired the really easy fix of just doing the cam chain tensioner check but no luck there. I now have the decompression spring, etc. so will tackle that next. I'm a little confused by your statement about setting the TDC per the service manual? The valve gear section 4.17.2 tells one to: Take care to time up the camshaft properly. The crankshaft is locked at TDC by the special bolt which was fitted earlier (see 4.11). Position the camshaft so that the timing mark (A) is horizontal on the exhaust valve side. When I go to section 4.11 it show a bolt going into the gear box area from the front of the engine and says: Lock the crankshaft at TDC using the appropriate bolt (7), However it never says anything about removing the bolt and the parts manual show the bolt as a standard part? Are you telling me I need to do this locking of the crankshaft? And IF SO am I supposed to get a LONGER bolt to do the locking and then put the standard bolt that I removed back in afterwards so the crank is no longer locked? OR are you just telling me to line the cam gear mark up with the front of the head and mark the chain then hold it up and get it back onto the cam gear in the same place? Sorry for all the questions - but I really appreciate your help!!! It also looks like you are telling me I don't need to remove the engine (but rather can just drop the front down)! YEA! THANKS AGAIN!!!! Quote Link to comment Share on other sites More sharing options...
bigbird2 Posted October 21, 2013 Author Report Share Posted October 21, 2013 Well I just got the top part of the cylinder head off and found what at least some of the problem is. The fiber cam chain guides are destroyed and the red stuff is all over inside the top head, etc. Thus the cam chain is very loose and the cam can be rotated quite a bit with the crank stopped. SO now I'd appreciate any help you can offer on what parts I will need to fix this (besides the obvious cam chain guides). Also will I be able to insert the new cam chain guides without removing the cylinder head and/or cylinder, etc.? Is there a way to determine if the cam chain and gears are OK? The cam chain can not be significantly pulled away from the cam gear at 12:00 o'clock if the chain is held against the gear at 3:00 and 9:00 o'clock - so my initial assumption is it is OK. Right now the engine is still in the frame (but dropped down a little to get the cam cover off) with all the wires and carb, etc. attached and with the swing arm bolt still installed. Will I need to remove it? OR can I get the side cover/case off and the new cam guides installed with the engine still in place? Thanks again for your help. Quote Link to comment Share on other sites More sharing options...
nzralphy Posted October 28, 2013 Report Share Posted October 28, 2013 Just to be sure the valves haven't touched the piston and need replacing..... I'd be removing the cylinder head. Quote Link to comment Share on other sites More sharing options...
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