81 GS550 transmission issues

[CincinnatiKid]

Who's been inside of these?

i got a free project bike a bit ago, and just got it running today.
clicking through the transmission, and unfortunately there are false neutrals all over the damn place.
trying to see what my options are, and maybe chronicle my attempt to fix it.
haven't put it on the road yet for a rolling test, but it shifted very poorly with the engine off and rolling the wheel by hand, as well as on the centerstand and the engine idling. i dont expect a road test to be any better...

and the first start video, because who doesn't love a first start video??

cool thanks!!

[Nessism]

You can't test the transmission by shifting without the engine running and the bike stationary. Regarding the engine, the airbox needs to be on for the bike to run decently. Try touching each pipe from a cold start to see if each cylinder is running.

Oh, and please check the newbie mistakes thread to see if anything applies.

[CincinnatiKid]

Okay crisis averted.
its a Japanese engine. I shouldn’t have worried.

As seen, i got it all patched up, put together, and ready for a road test.

it shifts exponentially better, though still had a tendency to get caught in neutral land when downshifting from 4 to 3. But overall, shifts in a predictable and consistent manner. It only acts up when trying to shift without using the clutch. Imagine that!!!

it was making a strange noise, a tapping sound, most pronounced when listening near the right side muffler. The headers seem quiet and don’t feel like there is an exhaust leak there. Just opened the valve cover and checked all the clearances, thankfully they are all consistent. Maybe just a tiny hare out of spec on the loose side. I’ll take it, and wait for them to tighten up on their own.

[CincinnatiKid]

As I think about it, loose tappets, helping keep the valves cooler, will be an asset in the quest for the ideal stoichiometric ratio... the machine arrived to me without an airbox, and I’m going to run the short UNI black cylinder pod filters on this engine.

Also, unless something terrible happens, this thread is no longer dedicated to transmission issues.

[Nessism]

You will have to rejet if running pods. A Dynojet kit is the simplest way to proceed. They sell a 550 kit for the 550M but it will work on other 550 bikes running CV carbs.

[CincinnatiKid]

running pods on my 1100E, put a stage 3 dynojet kit in there, and still have had to adjust the needle and main jet a number of times to get snappy throttle response dialed in between off idle and 1/3 throttle. i have some leftover bits from the last dynojet kit, i may be able to make some magic happen with them to keep some dollars in my wallet.

ordered sprocket, clutch pushrod, and gearshift oil seals. one of them leaks. might as well get 'em all. chain needs a good kerosene soak. rear sprocket looks pretty healthy. threw some intake manifold o-rings into the cart, out of courtesy for my man Nessism and his top 10 thread. found a left passenger footpeg on ebay for 10 bucks. a steal.

also put in a 200 pc order of stainless steel hardware to swap out (almost) everything thats a) phillips or b) rusty or c) both.

[CincinnatiKid]

all the work is completed on the bike, it runs well enough.

the transmission still does have issues, though not as dramatic as I had originally felt.
shifts well up from 1 through 6, but has downshift issues.
the trans won't let me downshift from 3 to 2. the gear indicator will flash 2 for a second, then when the clutch is released, the trans pops back up into 3. this happens over and over. no terrible noises or anything, but it won't stay in 2nd gear. a double downshift gets you into 1st, and it's fine.

i assume this is a bent shift fork? not gonna fix it, but i am interested in the cause.

[CincinnatiKid]

So the bike is as fixed as it is going to be.
on sale for $1490 on Chicago craigslist.
transmission issues still exist. Lots of false neutrals, and trouble getting it to click into gear and stay there. Once it’s in gear and engaged, it won’t slip out while under load, but sometimes it takes a few tries to upshift into 4th or 5th, and down into 2nd.
as an experienced owner/rider of $h1t bikes, I have no problems riding it around town and operating it safely, but it’s a different thing for someone who is test riding it. The problem seems worse than it actually is.

any ideas about oil weight, and how that might help or hurt this issue? It’s got Rotella T6 in there now, 15w40. Try something heavier? Lighter?