[wheeler]

So I obviously missed it last year & thought my clutch cover was leaking above the kick start. Turns out there is a hairline crack in back of where the mount is!! Unreal. Camping/quadding season just kicked off for me. I’ll have NO time to fix it properly before winter as it’s in full swing here. I’m going to degrease, sand it & either JB Weld or black oil resistant silicone/gasket maker. Just need to buy time!! I’ll post up pics when I get better cell service.

 

[fishfiles]

Thus stuff is better than JBWeld

 

[fishfiles]

Some more info on the stuff , I seen it go locally for any wheres from $16-19.99 ---I have used it about 4 times now , the most extreme and why I bought it was I had a lug that spun in a drum from the nulling stripping on the lug , I applied the stuff waited 10 minutes an hit it with a 1/2 air impack and it held ---- I used it yesterday and stuck a stainless eyelet in the end of a handle for my bell on the porch

 

[shadetree]

and would all that add-on crap you did to it cause this crack ?. I dont know ?, just asking . I have never seen them crack at that spot, most oil leaks i've seen are from a stripped oil drain plug ?, or a bad gasket matting surface ?.

 

[wheeler]

and would all that add-on crap you did to it cause this crack ?. I dont know ?, just asking . I have never seen them crack at that spot, most oil leaks i've seen are from a stripped oil drain plug ?, or a bad gasket matting surface ?.

I've never seen one crack there either. It is possible because of the extra power it caused the crack, but I will never know for sure. When I split the case & put a new one on, if it cracks there as again, then I guess we will know the answer....


Add on crap lol? You mean a bbk to make more power? lol.. You're funny shade!

 

[shadetree]

and would all that add-on crap you did to it cause this crack ?. I dont know ?, just asking . I have never seen them crack at that spot, most oil leaks i've seen are from a stripped oil drain plug ?, or a bad gasket matting surface ?.

I've never seen one crack there either. It is possible because of the extra power it caused the crack, but I will never know for sure. When I split the case & put a new one on, if it cracks there as again, then I guess we will know the answer....


Add on crap lol? You mean a bbk to make more power? lol.. You're funny shade!

not the top end crap, the clutch kit stuff, surely this would cause extra stress on the engine cases, and tranny.

 

[fishfiles]

No BIGGY with a cracked case ------- I had two different 300 cases with cracks in them this year , first one no doubt was the PO beating the side cover at the bearing holder and cracked the side cover , I could have fixed that crack , just threw another cover on it --------- then I found a chunk of case that was right on the threaded bolt hole , I was able to fix that one by making it into a stud instead of thread bolt hole , used JBWeld on that one ---I am liking that CRC Minute Mend better and JB Weld , it can be shaped smooth during application before quick curing , in other words , it stays where you put it

 

[mac102004]

and would all that add-on crap you did to it cause this crack ?. I dont know ?, just asking . I have never seen them crack at that spot, most oil leaks i've seen are from a stripped oil drain plug ?, or a bad gasket matting surface ?.

I've never seen one crack there either. It is possible because of the extra power it caused the crack, but I will never know for sure. When I split the case & put a new one on, if it cracks there as again, then I guess we will know the answer....


Add on crap lol? You mean a bbk to make more power? lol.. You're funny shade!

not the top end crap, the clutch kit stuff, surely this would cause extra stress on the engine cases, and tranny.

no.........

 

[mac102004]

Weld it. Surely you can find someone in oilberta that can weld aluminum lol

 

[_Wilson_]

tuned in.....

 

[fishfiles]

I think TIG would be the way to go , less heat , cleaner smoother weld ---- did you see the video of them new welding rods that you use a propane torch to apply , pretty smooth welds , works on aluminum , stainless , brass , steel , you can fill and weld a 1/2 inch hole in a beer can , don't think it would be the way to go on this case job , too much heat , just saying

 

[wheelsquad]

I would say most likely culprit to cause the crack was a loose motor mount somewhere else, forced too much of the load to this point. Or just a defect in the original casting that finally gave way. I also tend to not think that hp had anything to do with it cracking. Honda builds 60+ stock hp CRF450R's with similarly thick cases.
@fishfiles I saw ads for those aluminum welding rods too. Not sure what to think of them yet, time will tell. X2 I'd definitely find someone good at TIG for this repair.

And then check all remaining motor mounts and swingarm bolt before riding again...

 

[SamUK]

TIG it up, simple job that could be done without the motor being stripped. Quite possibly a job that wouldn’t even require a filler rod! @shadetree none of the mods @wheeler has done would affect the casing, not unless he’s achieved the impossible and gained 100+ HP lmao.

I think wheelsquad is on the right trail with the loose motor mount, maybe not in wheelers time of owning the ATV but at some point in its life at least.

 

[_Wilson_]

Didn't you have an issue (at one time) kick starting this same machine ?

Edit: ^^^ reminds of this thread.

https://www.hondaatvforums.net/forums/repair-maintenance/125834-ole-300-gonna-get-sime-tlc.html

 

[wheeler]

Well I tried JB Weld as I had some at home.. Put 2 separate coats on kinda like layers over a few days to fully cure. Went out on our annual 10 day bush camp trip. Though perfect it's holding & no oil leak. This I kinda decided as it was warming up & all looked good. I took er out for a few mile ride to see how it was going to be... NOT GOOD! It's not leaking from the crack any more, but rather what appears to be right where the motor mount bolt goes thru the case.. So I brought er back to camp & parked it. Looks like I need a case & complete rebuild while apart, or a running motor I can swap my my BBK & parts over too...

 

[wheeler]

Yesterday I thought I had an answer as to how I was going solve this issue.. I went & looked at another 300 4x4 lol. It was in good shape for a 94, worked & shifted beautifully with NO oil leaks, noise, or any bolts on the engine that looked like they had been removed or messed with. The guy wanted $2000, & was willing to take $1800. I told him I wanted to think about it & get back to him. So I did some really good thinking... to spend $1800 pull the motor which was solid, swap everything over then have to re-sell with a broken motor & or keep everything as a spare.... Not worth it. I'm going to pick up another crank case, pull my motor, rebuild the bottom up, inspect my top end & have a brand new motor.... I can do that a lot cheaper then buying a whole atv for just a motor... I sent Charlie Long a message to see if he has a "good" case... IF anyone on here has a "good" case send me a PM as well. I prolly won't get to rebuild the engine until fall as I will need to use the quad for hunting season.. I'll just have to carry some oil with me...

 

[Orvis25]

@wheeler

If the crank case is aluminium (i think it is) you can use this from harbor freight.

https://www.harborfreight.com/8-piece-low-temperature-aluminum-welding-rods-44810.html

Basically its brazing, but stronger?? There is a dude on YouTube who used it to make a mini-bike frame, and it held up his weight (he was a heavy dude).

All you need to do is clean, de-grease, V cut, and torch it on, Done.

Granted, iv never used the stuff i admit, but it seems ideal and better than an epoxy for the situation (aluminum on aluminium, plus it will seep better into the cracks than a putty or thick epoxy)