Side plate bolts keep backing out`

BWL

Active Member
#1
Man, the side plate bolts on my BSP motor keep backing out. I torque them to 17 lb-ft. What is it? Do you guys use lock tight or something? I even loose a bolt most every trip out on the river. Weirdest thing ever. Never had this problem with any powerhead before now.
 
#2
Yep ..locktite , clean the bolt holes and bolt threads with a good carb/brake cleaner and let dry ...then locktite them...I use red locktite myself.

 
#4
I personally use LocTite red 262. It is the 271 in a high-temp form. I used it on the rear caliper of my Carbide. Works great. The only thing is, if I want to take the caliper off, I gotta cut the bolt.

For you, I recommend the 246. It's high-temp blue. You could still crack it loose if you need to but it'll stay good on the lake. McMasterCarr is a good seller of LocTite. Buy the smallest bottle because either way it'll last you for years.
 

noseoil

Active Member
#5
Check crankshaft end-play & see where you are, if it's too tight, the bolts can work loose. Changing gasket thickness is really the only simple way to change the end-play to loosen things up a bit. You should be able to grab the crankshaft & feel a slight amount of play when you push & pull against it. If it's tight, then you will never get the bolts to stay in place.

This is what I made to check on the new build, it's crude but works well enough. 10-15 thousandths is about right for the motor to run well & not have problems. It's just a cheap ($16.00) dial indicator & some scrap aluminum that bolts onto the side cover to check the slop.

Crnk-Setup.jpg

I went with studs on the new motor (but it's not run yet, so take what I'm saying with a large pinch of salt) & used red loctite to set them in the block so they stay put for good. With the studs & loctite, you can run 20 ft/lb on the flange-nuts for a better grip & not worry about it. If you continue to torque the bolts into the aluminum case, it can wear out the holes over time & create problems. Blue loctite is the best option for bolts & aluminum if everything else is good, but check how tight the crankshaft end-play is first, to make sure there isn't a lot of force pushing out on the side cover which is working the bolts loose.
 
#6
I went with studs on the new motor (but it's not run yet, so take what I'm saying with a large pinch of salt) & used red loctite to set them in the block so they stay put for good. With the studs & loctite, you can run 20 ft/lb on the flange-nuts for a better grip & not worry about it. If you continue to torque the bolts into the aluminum case, it can wear out the holes over time & create problems. Blue loctite is the best option for bolts & aluminum if everything else is good, but check how tight the crankshaft end-play is first, to make sure there isn't a lot of force pushing out on the side cover which is working the bolts loose.
I'm also a firm believer in studs. I learned to ditch the bolts the hard way after stripping the exhaust flange bolts out of the head on my Carbide. And right after I did a P+P, so I wasn't getting a new head.

Also remember, if you use red LocTite on the studs, use blue on the nuts. I learned that one the hard way too.
 
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