It's running again! Part 2 of 2 - adjusting valve lash on a Polaris 570 - Final Assembly!
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- čas přidán 12. 05. 2023
- Part 2 - • It's running again! P...
Dwight is our 2018 Sportsman ACE 570, and it has developed a new problem where it is very hard to start when cold, and it won't idle until it gets warmed up. It only happened occasionally at first, but now it is hard to start every day and takes a while to get it idling reliably. Once it is warmed up, it runs perfect. Fuel is good, throttle body is clean, has spark, no check engine light.
This led me to believe that there was an issue with compression. Unfortunately, these machines cannot be tested for compression traditionally, but I knew that it has a new top end.
In the end, I checked valve lash. Much to my surprise, the valve lash was too tight! This will definitely effect the compression which explains why it was hard to start.
Today is part 1 of this procedure. How to check and adjust valve lash on a Polaris 570 engine. I'll take it apart and measure the clearance. In next week's episode, we'll put it all back together!
Thank you so much for watching. If you aren't a subscriber, consider joining! I really appreciate every viewer and every subscriber! - Auta a dopravní prostředky
I just used a Dial Caliper and a Dremel, calculated what I needed to shave down on each shim bucket. Got my lash in spec. I didn’t even change the valve cover gasket. It cost me no money. Runs good.
You know, I didn't even give that any thought. Definitely could have tried that instead of forking out $40 a pop! Even if you mess one up, just get a new one. Great pointer! Thanks for sharing!
It's so funny when you start putting the cams back in and putting the bolts in and I thought I missed somthing. backed up 3 times to see you put those shims in.😊
Haha yeah, totally forgot about them the first time around! Kind-of a fundamental piece of this operation!! Thanks for watching!
Just curious of why you got a 510 for right side exhaust but dropped it down to a 502?
My math was wrong in the first one. When I put it in the site it came up with a different value, so I double checked everything and confirmed that I had calculated wrong. 502 was the right one after all. It has been a year and it is still running great!
Where did you order the parts from? Same problem with intake valves, can't find site to order from??
Partzilla.com or RockyMountainATV.com has them. Just look for the OEM parts catalog and drill down to your machine.
I think you've helped me narrow down my 570 crank, no start issue. BUT my intake lashing is over .026" but my exhaust is perfect. Everything is in time too. What can cause loose lashing 4-5x more then spec?
That is interesting. I've never seen the lash get looser - only tighter. As dust gets in there, it will wear away at the valves and seats which allow the valves to seat in deeper resulting in a tighter lash. I'm not sure what would cause it to be looser. Perhaps something is jammed in there? Or the cage that holds your cams down isn't seated right? I'm really not sure. I'd probably pull the head and lap the valves in an effort to get everything clean and seated properly before setting the lash. Those shims are $40 a piece! I'm curious as to what you find for sure!
Thanks for the reply, I ended up taking the head off and the intake valves ended up being bent. There was about a 16th of an inch gap between the valve and the seat.
Neither the valves nor the piston looked like they hit, so I don’t know what the cause was
which way does the engine turn?
From the clutch side, counter-clockwise. From the stator side, clockwise.
Where are you located, I think my rzr 570 is doing the same thing and was wondering if your interested in working on it, im in ohio
Hey there! I'm way out in Upstate NY. It's not a terrible job, but it would take less time to fix than to drive all the way out here! Make sure your intake hoses are tight and your air filter is intact. Although it could be from regular wear and tear over time, I've found that the valves typically do this when they either take in mud (as shown here), or there is a hole in the air filter (mice like to chew on the bottom of them), or an intake hose is loose so it can suck in air after the filter. Finding and correcting that will at least stop it from getting worse!
hey i have a powersports repair shop in new york is there any way i can send you my contact info i have a few questions on how to replace the shims in the old tappets
Hey there. I have my email address listed in my "about" page on the channel.
curious on that calculator. You measured in thousandths with the feeler guage, then that calc was showing mm.
I did measure with thousands, because that's what I usually measure valve lash with and the service manual had the tolerances in both in and mm, but then found that Polaris measures shims in mm, and the calculator was in mm. The gauges have both mm and in measurements on them so it was a quick conversion to switch to mm. So far so good with the new shims! Thanks for watching!
What if you have zero clearance on intake.
How do you use calculator?
Shouldn’t the clearance be the same for the set? Intake should be same and exhaust the same? I’m just trying to figure out why the tappets could be different on the same set.
In a perfect world, yes, you would expect them to be the same. However, each valve can be seated into the head at a slightly different level than the other, hence the shim being different between the two. As you "lap" a valve, you're grinding it deeper into the port, which will make the gap tighter. It is fairly common for them to be different by a little bit from the factory, but it can get much worse if it sucks dirty air and you have to re-lap the valves. Hope that helps!
Very useful information!
Would you mind sharing where you purchased the tappets? I have a set to change in the same engine as in your video…. With the same exact issue. Also I saw the video of you changing the valves in that bike. Do you recommend changing the valves while changing the buckets? My bike had a lot of dust intake at one time. Thanks
@@user-ro8cw6td9k I purchased the tappets from Partzilla.com. And yes, if I were to do it again, I would get new valves, lap them, assemble it, take the machine out for a few runs to let everything settle in, THEN I would measure the tappets and adjust as necessary. Ended up having to do it twice this way!
@3dayweekend. As you lap a valve, you're setting a deeper into the seat, thereby moving the valve stem closer to the camshaft. The valve lash measurement will be tighter, requiring a thinner shim, not thicker.
@@dannyjamison8337 Yes, you're correct. I said that backwards. I've updated the comment. Thank you!