calling SX engine experts

[redsox]

I went for a little ride last week and had a breakdown. Everything was going fine. Riding pretty hard, all of a sudden, had what felt like a half shift and it was like i was stuck in neutral. shifter felt good. it was working up and down. obviously not a return spring pin or gearsift arm. each shift just felt kind of empty. like it was half-engaging. anyway,,, i just got around to taking the case covers off and everything looks good. except, that the shifter bolt was hand tight... not even. in fact, the bearing came out when i turned out the shifter bolt by hand. was that my problem?? anyone??

[Flyingw]

Which bearing came out?

[redsox]

driver's side. the bearing at the end of the shift drum that touches the "shift drum center". i think i was missing the pin.

[Flyingw]

Oh man!!!! if that bearing fell out and the shift drum tilted down lets say, that may have been enough to let the shift forks come out of their grooves.

[redsox]

yup. thats what the experts are saying. very,, very sad. is there a way i can see that? can i look in somehow and see?

[YTZ drew]

I have no sx experience, but have split many cases. If its possible with that engine, I would try to "wiggle" and work the drum around as much as I could, trying to feel if the forks are still in engagement with the drum, and possibly let one drop back in if it came out. Most engines don't have too much room in there, so maybe the forks didn't fall completely out of their locations? If you need any help splitting cases, I'm not far from you and willing to lend a hand.

[redsox]

well, Drew, its possible you are a freakin genius. i call this repair the "jiggle the handle technique". it works on leaky toilets and 86 250sx shift drum forks. depressed by the prospect of splitting the cases, i figured i'd try working the drum around a little, and re-assemble to see what happened. after only a couple of seconds of moving the drum (it didn't move much) i could feel it go back into place. i put everything together and she's good to go. amazing. i had no faith in it working but it did. i've got to go back in at some point and replace the case gaskets. i'll do that after a ride to see if anything is moving around. has anyone had this bearing come loose? i torqued the bolt down pretty good. i'm wondering if i should have put a little loctite on there? i can do that when i change the gasket. any thoughts?

[oscarmayer]

I usually use the lowest grade loctite I can find (green) on any internal engine bolts that hold major parts on. I think it is just good practice and FYI, Honda does that too in most cases. I think someone was in that motor before you because the drum should have had some loctite or similar residue when disabled.

I would loctite it with the green stuff and torque it. should be good to go after that. of and FYI don't use Carb. cleaner to clean the parts for loctite. use "brake" cleaner. Carb cleaner has a tiny but if oily residue where brake cleaner does not.

[YTZ drew]

SWEET! I'm glad that worked for you! I'm with Oscarmayer, I'd use loctite on any bolt inside the cases just to be safe. I too use brakeclean on the threads, then blue loctite. I figure I can always heat the bolt slightly to soften the loctite if I need to disassemble in the future.

[fabiodriven]

Great to hear Dan. I'm really glad you didn't have to split the cases as I was just discussing SX engines with my brother last week. He had someone drop off an SX basket case engine at his shop for assembly. My brother is VERY capable of assembling an engine as he's been doing it for 30 something years or something like that, and he said the SX was the biggest pain he's ever had. He used to work on super bike pit crews and the last time I was at his shop he had a Honda Interceptor 1000 (one of my all time favorite street bikes) engine on a stand after he had just assembled it. If anyone is really bored, Google the drive for the cams on that engine. No chain, all gears. It didn't look like anything I wanted any part of.

[oscarmayer]

^ LOL yup! why do you think I try NOT to work on SX/SE motors? I don't mind top end, but bottom ends? forget it. "where's that ebay link again for a good bottom end?" hahahaha

[redsox]

yup. i'm afraid of it.

[Flyingw]

Bottom ends are easy!!!!! Weenies.....

[oscarmayer]

^ not the 250 ones. they are different.

[Dirtcrasher]

Dan, if that bearing is loose in the bore, they make "cylindrical loctite" It takes up to .020 or twenty thousandths of play and then you can use the Loctite blue on the bearing retainer bolt. It will require a little heat to get the cylindrical loctite out years down the road......