Hi, is that the break-in procedure the manufacturer of the new top end kit recommends? I've never been a fan of breaking it in like you just described for the initial run. Start it up, make sure there are no immediate leaks to be found through any of the gaskets and take that out for a ride, varying the engine speed on accel and let the engine brake under deceleration. The rings should be put under the load of acceleration and deceleration. Blipping the throttle or varying the RPM on the bench or idling puts little, if any, load on the engine in the context of actually breaking it in.
2007 Yamaha Grizzly 350 low compression
- Thread starter nwjones18
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The kit came with no instructions whatsoever... When I did my initial start the bike wasn't assembled enough to ride, and it also had no brakes. I got the brakes 1/2 way working and the next run was as you described. Here's a picture of all 4 front brake pads that came off of it for everyone's amusement:
Outside pad metal backing was eaten through on both sides and the rotor had carved into the caliper itself so much I'll have to replace them. Overall this thing has received an impressive lack of maintenance.
Been on a couple 20min rides now and it seems to really be running well. Has a slight cough at idle that will occasionally kill it, but I can get carb problems fine tuned later.
^^^Ditto^^^
Good work!
Thanks all. I'll report back after I get a few hours on it. I'm thinking I'm not going to let this first oil change go over a couple hours.. those 12 gallons of Delvac I got for $13 on that last walmart pricing mistake finally coming in handy!
Changed the oil at 2.2hrs today.. I was expecting there to be some metal considering how the engine looked when I had it apart but it was a full on panning for gold experience.
I don't think the oil/filter that was on it had ever actually been run so perhaps this is all just left over.. Regardless it makes me think this story might not have a happy ending. Which wouldn't be particularly surprising.. Guess I'll run it for another couple hours and see if it comes out looking the same. On the bright side the Fram PH6017A seemed to be a perfectly serviceable filter. Replaced with a PH6607 which seems to be the same filter but in an orange can.. I do wish it would have caught more of the metal, but there was a lot in it for sure.
I don't think the oil/filter that was on it had ever actually been run so perhaps this is all just left over.. Regardless it makes me think this story might not have a happy ending. Which wouldn't be particularly surprising.. Guess I'll run it for another couple hours and see if it comes out looking the same. On the bright side the Fram PH6017A seemed to be a perfectly serviceable filter. Replaced with a PH6607 which seems to be the same filter but in an orange can.. I do wish it would have caught more of the metal, but there was a lot in it for sure.
It has to be moving for air to cool it.
Most of that looks like big particles, so perhaps most of it was just laying in the bottom of the engine until the oil was drained. If any of it was floating around while running it should have been caught by the oil filter. It's probably large particles left over from the piston and bore betting torn to shreds. Don't give up hope yet.
What does the inside of the filter show? Take a look in the pleats and see what you have for additional debris.
What does a magnet say about the particles in your picture?
What does a magnet say about the particles in your picture?
Latest update. I'd been noticing some clatter in the top end and recalled that the timing chain tensioner was fully extended when I pulled it apart. Well my chain is stretched out enough to slap the side if the case.. What was making it worse is I installed the front timing chain guide incorrectly.. The installation instructions in the service manual were everyone's favorite "installation is the reverse of removal". When I'd removed it I'd just lifted it out of the crankcase, when I put it back in I just dropped it in in a way that 'felt right'.. Now that I have the crankcase cover/flywheel/starter gears off its abundantly clear that I didn't install it right and it got chewed up, so I've got new timing chain and guides otw. On the bright side when I drained the oil this time it came out clean with no visible metal pieces, so maybe I'm still headed in the right direction.
if rods are good looks like its worth doing. In my old foreman i bumped up the compression a bit with the top end kit and used zero gap rings without issue. torquey engine pulled noticably better after. Check the head for flatness.
Good catch on the timing chain guide. Good to hear the oil is looking good!
Got the new timing chain and guides in today. Thankfully that could be done without taking the top end apart again. I measured the links on the new/old chain and the old chain was stretched by nearly 1/2 an inch. Tensioner was fully extended with the old chain and it still had to much slack and with the new one its 1/3 extended and the chain is tight. Cranked up and sounds like it should now. I still have some carb work to do, some more brake work and it has an exhaust leak. I went ahead and ordered a set of tires for it today, so I'm going all in on it being good to go now. Will put up a pic when I get it finished. Thanks again for everyone input. Definitely was more of a project than I had initially thought it would be!
That thing has been through the ringer to be in such bad shape
Figured I'd post an update. I've got 10hrs on the 4-wheeler now and rode it for 2hrs straight yesterday and its still running really well. I ended up having to replace front calipers and pads and change the rear axle bearings and seals in addition to doing the top end and the timing chain. I bought one of the cheap chinese carbs and it was garbage, but I was able to use it as a rebuild kit for the stock carb. Overall I'm very pleased with the end result. The 350 has plenty of power to carry around my 250lb self and stuff. Here's a pic of it with the new tires and my setup heading to the hunting club the other day. I need a bigger trailer..
Good job! ride the old girl in safety and she will serve you well. Your sense of accomplishment pays for all busted knuckles.
Smoky
Smoky
Congrats on a nicely done resurrection!
is that a honda atc185 ?
i know its not a 70,90,110,200x,250r
well at least you have brakes and a motor but now need a camchain
if you can double check the teeth on the crank n make sure they are not sharks teeth
and just realize that then you re-torque the cam caps after having to lift them to put the new cam chain on, it really is that low of a torque value (usually under 10nm)
i know its not a 70,90,110,200x,250r
well at least you have brakes and a motor but now need a camchain
if you can double check the teeth on the crank n make sure they are not sharks teeth
and just realize that then you re-torque the cam caps after having to lift them to put the new cam chain on, it really is that low of a torque value (usually under 10nm)
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