bluesmokeracing
Ruckster
vote for me and all your wildest dreams will come true
Posts: 253
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Post by bluesmokeracing on May 19, 2005 17:32:07 GMT -5
Chanito: I don't totally understand what you mean by 'sink the valves in the valve seat'. Can you explain a bit more simply for us dummies out there and perhaps explain why this is bad but the H.O. cam isn't. (or does the H.O. cam cause this too?). By the way new valves are less than 10$ each (US$) but the work involved would likely be a chore. this is when your valves get tight from the seats moving up in the head. i would definately be concerned with an exhaust valve burning with a tolerance that tight. the problem is if the valve is .04 cold when the motor heats up the valve will be .02-.04 or so open b/c of thermal expansion. this is why you set the valves cold. when the motor warms up the tolerances become tighter, probably .04 or so tighter than the spec cold. when the valve hangs open, stuff burns. the cam might cause a little extra seat movement but nothing that cant be shimmed. it depends a lot on the ramp profile on the trailing edge of the cam lobe. the exhaust valve tends to get more of the heat, too, hence the .19spec vs the .10 on the intake. i have a valve here at my house from my buddies car that has a 1/4 inch hole burned right in the middle from driving home with a cracked exhaust manifold. the valves are cheap, but i would lean towards the honda spec. my valve lash was at .12 ex and .02 intk when i checked b/c it would hardly run from losing compression when it warmed up. .05 smaller shims livened it back up
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Post by Dandy Dan on May 19, 2005 18:37:08 GMT -5
Great response ;D. Thanks! So basically you want the gaps as tight as possible while still safely ensuring you are keeping some gap. Honda's suggested gaps are a good suggestion but probably side on the safe side so you could likely run say .15 instead of .19 but definately don't go way down.
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Post by chanito on May 19, 2005 19:38:24 GMT -5
Sorry lets me explain this further, somewhere i explained this before, but any way since are engines are rev so high all the time, and the valve have a design that makes them rotate they have a tendency to wear in the seat area more so than your common car valve (just think if a car engine spend 25% of its life above 5k that is a very hard runned engine, but our engines spend about 75% of its life above 5k) as the valve head and the seat wear your valve gap becomes smaller, untill finally you have none and you end burning your valves and sometimes damage your head, to be safe i would set up your valve gap on the loose end of the specs, and check again in about 600 miles or 1000 km, (always check them cold) and if you see no significant wear, then set them tighter
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Post by wontstart on Aug 12, 2005 17:14:18 GMT -5
my 2003 honda ruckus wont start.I was told i was having blowby on the intake valve,,,,,does this mean i will need a thicker shim or thinner shim, i dont see a number on the shim i removed. i was told i didnt have enough compression,what should the compression be / thanks
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Post by chanito on Aug 12, 2005 18:46:28 GMT -5
If your valves are too tight you will need thinner shims, if the number stamped on the shims are worn out you will need a micrometer to find the size, by the way the clearances are .10 mm intake and .19 mm exhaust, of course with a cold engine and cylinder compression should be about 200 psi (yes i know, it is high), hope this helps
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Post by wontstart on Aug 12, 2005 23:25:07 GMT -5
so if i go with a smaller shim this will let the valve seat all the way and not allow blowby therefore allowing more compression to start my ruckus. am i on the right track ?
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Post by chanito on Aug 13, 2005 4:37:21 GMT -5
yes, you are correct
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Post by wontstart on Aug 13, 2005 14:55:06 GMT -5
have tried several different shims,still only have about 50 on compression,what should i look for next,,rings,valve seals?
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Post by wontstart on Aug 13, 2005 17:39:53 GMT -5
when checking for my clearance,i cant seem to find a guage small enough to slide in there,i think my valves are way to tight,,,,,especially the intake, what would this mean, i added oil to spark plug hole,did not see an increase in compression,,,,not sure if the valve seals are bad or not,,,,,,,are they hard to change out ? any pictures out there of it
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Post by Dandy Dan on Aug 15, 2005 17:43:54 GMT -5
I have some pictures just go to:
photobucket.com/albums/y210/dandurston/
If you scan through the pics you'll see a few of the valve seals. They aren't that hard to change. You need to compress the valve springs to get them off but the springs are pretty week so you can do it by pushing down with a socket. If you have a valve spring compressor that's ideal but i didn't use one. The seals just slide down the valve and are held in place by a simple wire ring.
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Post by chanito on Aug 15, 2005 19:15:31 GMT -5
i need to close the gap to Dandydan posting so i will post the adjusment page from the service manual here anyway hope this will help with the valve adjustment
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Post by wontstart on Aug 15, 2005 21:47:16 GMT -5
good news,i got the kids ruckus running again,,,i found the right shims, the magnet also works well when removing the shims! thanks for everyones help ! Now the kid wants it to run faster,,,,,,,,,,,so i guess thats my next project ! thanks again !
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Post by Dandy Dan on Aug 16, 2005 7:56:13 GMT -5
That's good to hear. You seem to have a lot of persistance. I'm still amazed that just a shim issue could cause such extensive problems. Anyways, is it running good or just running? You should have a top speed of about 36-37mph if its running well.
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Post by wontstart on Aug 16, 2005 12:18:59 GMT -5
currently its only running about 33mph, the shims may not be perfect, i was surprised that the shims fixed it also, i cleaned all the connections ,changed the oil, flushed the radiator,changed the filter,cleaned the carb,replaced the idle jet,replaced the bystarter auto, i think thats about it,so hopefully it will run for a while
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Post by chanito on Aug 16, 2005 17:17:23 GMT -5
Congrats, great job my friend, i am really amaze at the fact that you did not give up, and went on until you fixed, two thumbs up ;D ;D. By the way what is a by-starter auto?
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Post by Ruckedup cody on Apr 8, 2019 21:03:13 GMT -5
Came across this post. I am going to do the intake shim tmrw. I wasnt even able to slip a .04mm feeler.. (smallest feeler gauge in my set) in. So I guess my question is could that cause my ruckus to not start all together? Before checking the shim I did a carb clean,fuel drain,and spark test all to find frustrating dead ends. My Hope's are that tmrw my ruckus will start for the first time since I've bought the money pit. Any input would be awesome.
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Post by Thirstyislander on Jul 5, 2020 14:25:19 GMT -5
Exactly the same with my 2005. A very slow start. We replaced: fuel/air filter, gas pump, carb clean, new spark plug, new bystarter, oil change). The intake is super tight, with 228 shim. The exhaust has more room, which I did not take out yet. After reading all this GREAT advice, we will try again to see clearances when it is dead cold. Then we will do the calculations. I'm hoping this is the LAST thing b/c we are getting very frustrated. Good to know that others have good advice though
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