DLBeltran74 47 Posted August 27, 2021 Ok, question. I have a 2003 Honda Foreman TRX 450 FM. I currently have the engine out of the bike and the top end off. Everything looks good but I was wondering what can I use to flush it out before I put the new top end on and put it back on the bike. I want to do it now but don’t know what to use. I was told that I could use diesel but I have my doubts. Does anyone else have any good suggestions? Share this post Link to post Share on other sites
_Wilson_™ 6,593 Posted August 27, 2021 (edited) i would think diesel would be fine.... but i would do a couple oil changes afterwards. Edited August 27, 2021 by _Wilson_™ 2 Share this post Link to post Share on other sites
jeepwm69 7,751 Posted August 28, 2021 Lots of guys use diesel to try to flush them after they sink them. I wouldn’t leave it in there long, but it shouldn’t hurt to flush it out a bit. As fish said, change the oil a couple of times afterwards 2 Share this post Link to post Share on other sites
Goober 1,555 Posted August 29, 2021 if it looks good why does it need flushing? Not trying be a wise guy but what are you trying to remove? 2 Share this post Link to post Share on other sites
Orvis25 108 Posted August 29, 2021 On 8/27/2021 at 4:27 PM, DLBeltran74 said: Ok, question. I have a 2003 Honda Foreman TRX 450 FM. I currently have the engine out of the bike and the top end off. Everything looks good but I was wondering what can I use to flush it out before I put the new top end on and put it back on the bike. I want to do it now but don’t know what to use. I was told that I could use diesel but I have my doubts. Does anyone else have any good suggestions? Honestly, if its running find, i would not "flush" the crank case. I have seen people swear by diesel and a bunch of other stuff, but Project Farms (YT) tested a few, and every one led to cylinder wall/piston damage due to lack of lubrication when running the engine. The only on I have heard that can be done with no/minimal damage to your engine is vegetable oil flushing since it performs pretty similarly to 10w-30 for a while, and is super cheap and bio-degradable. Honestly. Unless it was sunk, I would just replace the filter, and treat it as normal. Maybe even ! a magnetic drain plug. Share this post Link to post Share on other sites
_Wilson_™ 6,593 Posted August 29, 2021 6 hours ago, Goober said: if it looks good why does it need flushing? Not trying be a wise guy but what are you trying to remove? @Goober here's the original post..... https://atvhonda.com/topic/1530-engine-question/?tab=comments#comment-48005 1 Share this post Link to post Share on other sites
DLBeltran74 47 Posted August 29, 2021 16 hours ago, _Wilson_™ said: @Goober here's the original post..... https://atvhonda.com/topic/1530-engine-question/?tab=comments#comment-48005 Well, it’s been sitting for a little while and I can’t guarantee nothing has made its way in there. I just want to be sure it’s clean before I start putting it back together. 2 1 Share this post Link to post Share on other sites
DLBeltran74 47 Posted August 29, 2021 17 hours ago, Orvis25 said: Honestly, if its running find, i would not "flush" the crank case. I have seen people swear by diesel and a bunch of other stuff, but Project Farms (YT) tested a few, and every one led to cylinder wall/piston damage due to lack of lubrication when running the engine. The only on I have heard that can be done with no/minimal damage to your engine is vegetable oil flushing since it performs pretty similarly to 10w-30 for a while, and is super cheap and bio-degradable. Honestly. Unless it was sunk, I would just replace the filter, and treat it as normal. Maybe even ! a magnetic drain plug. Well, right now the engine is off the bike and just sitting covered up. When I bought the quad, it didn’t have the top end on it. I just ordered the top end and I will be putting it on in the near future. So I just wanted to make sure any debris that might have gotten in there is flushed out the best I can before I start putting it back together. From just looking in it with the cylinder off, it looks great. Share this post Link to post Share on other sites
_Wilson_™ 6,593 Posted August 30, 2021 11 minutes ago, DLBeltran74 said: Well, it’s been sitting for a little while and I can’t guarantee nothing has made its way in there. I just want to be sure it’s clean before I start putting it back together. right, that's what i observed from your original post. Share this post Link to post Share on other sites
Orvis25 108 Posted August 30, 2021 1 minute ago, DLBeltran74 said: Well, right now the engine is off the bike and just sitting covered up. When I bought the quad, it didn’t have the top end on it. I just ordered the top end and I will be putting it on in the near future. So I just wanted to make sure any debris that might have gotten in there is flushed out the best I can before I start putting it back together. From just looking in it with the cylinder off, it looks great. Ah my bad, I misunderstood. I thought you put the top end on, but it sounds like you got it in 2 pieces (top and bottom ends) If so, ya "flushing" it with diesel could be feasible, but keep in mind it will in all likelihood also remove a lot of the oil residue in the bearings and stuff, so when its reassembled and filled, there will be a small amount of time that virtually everything will be "un lubricated" per say. I would say, if your really want to "flush it" (the crank case) for any larger debris hanging at the bottom, go with vegetable oil, since at least it will protect the parts and not leave them stripped of oils. Most likely cheaper too, diesel in my area is like $4.40+ a gal. Just buy a few gallons, poor it in (maybe shake her up if you really want to I guess), and let her drain out the bolt hole like a regular change. Nice thing about vegetable oil is its bio degradable, so even if you use 10 gallons to flush it, you don't "need" to recycle it like motor oil or used diesel (non-bio degradable). Poor it (the vegetable oil) over some weeks, poor some salt on the now sticky leaves, and boom, discount weed killer while your at is >.< If you don't see any big stuff, just pop the top end stuff on, fill her up with your oil, and run it. Just make sure to tune/align stuff first. Best of luck man. 1 Share this post Link to post Share on other sites
_Wilson_™ 6,593 Posted August 30, 2021 26 minutes ago, DLBeltran74 said: Well, it’s been sitting for a little while and I can’t guarantee nothing has made its way in there. I just want to be sure it’s clean before I start putting it back together. i understand, but .... i think you might over thinking this .... I don't think anyone asked you if, IF, you had a history of this bike, whether it had been sunk, but by the description... my thinking is it wasn't .... but fact is, if it has do what shade said all the way down... because you will not get all that grime out, that's why people use use thinner liquid to flush them.. but if your plans are to keep this bike for along time... do it right.... when you did the oil drain first time (soon as you got the bike) what did the oil look like ? i may have to look at your original post again, i don't recall right off hand. 2 Share this post Link to post Share on other sites
jeepwm69 7,751 Posted August 30, 2021 I have flushed with diesel before and it did not get all of the grit out. That said, it can’t hurt anything as long as you flush it out a couple of times with oil afterwards. Normally I split cases and clean everything out with starter fluid, which also leaves all of the bearings dry. I’ve gotten now where I fill the engine with oil and then roll it over a few times in the yard before I reinstall it in the frame lol Makes sure that there’s at least a little bit of oil on everything before I start it 4 Share this post Link to post Share on other sites
AKATV 850 Posted August 30, 2021 Yep same here, I split cases and use starter fluid too ( man that stuff has gone up in price...) Good maintenance and peace of mind, you would be surprised at the amount of gunk I have found and "sucked in" oil screens I have seen in engines that "looked good" I have a little cheapo oil squirter that I use to oil all bearings after, and I usually turn starter over until I see oil come out the oil bleed out screw on valve cover cover, then turn it it half a minute longer to ensure good oiling and flow before trying to start engine 4 Share this post Link to post Share on other sites