GB500TT intermittent loud grinding noise in 1st gear?

[Nausea]

My 1987 Honda GB500TT has a Intermittent problem where sometimes in first gear, it feels like I'm dragging a load & also from the gearbox comes a horrible scraping noise almost like I was dragging a heavy metal object over concrete.

I have to flick the gear lever up & down a few times to get rid of it. Most often the problem occurs if I've changed down into first from second but sometimes it will happen when going from neutral to first.

I've had the bike in a bike shop for a week but as Murphy's Law dictates, they cannot get the bike to make the noise yet it happens every time I ride it!

Any ideas what it could be?

Thanks :)

[Akzle]

then it could have something to do with how you ride, innit, since it only happens when you ride it. Innit.

[BuzzardNZ]

Plenty of grunt in those old things, just use 2nd instead.

[HenryDorsetCase]

worn engagement dogs on first gear pair? worn shifter drum or forks or bent shaft? issues with the drum or forks usually cause jumping out of gear though.



is there metal in the oil? like gear tooth size? usually thats bad.

[Murray]

Its stuffed - I'll buy the engine off you - how much???

[nzspokes]

Put a new spring on ya stand.

[Nausea]

Put a new spring on ya stand.

Haha... it does sound like that but definitely not the stand scraping.

@HenryDorsetCase - there was no metal in the oil when it was changed just prior to Xmas.

Picked the bike up from the workshop today & went for a long ride & was able to get it to happen again. Most likely to occur if I change into second quite low in the revs & sounds like it is coming from the front sprocket area so will take the cover off & have a look for anything obvious.

Annoying, I have been accumulating parts to restore the bike & are nearly ready to go but don't want to pull it apart & then have to do so again at a later point in time.

[FJRider]

Sounds more like clutch ... rather than gearbox.

Try 1st gear under load at low RPM .. then slowly increase revs .. (going uphill at the time shows it best)

[nzspokes]

Well dont worry, what ever is jumping around in there will come out through the case soon enough. Then you will know.

[gammaguy]

Na that won't happen

The gearbox will lock up, the bike will high side him and he will be so busy in hospital learning how to eat thru a tube and pee into a bag he won't worry about the bike anymore

Anyway it's harder to ride with only one leg:)

[Nausea]

Sounds more like clutch ... rather than gearbox.

Try 1st gear under load at low RPM .. then slowly increase revs .. (going uphill at the time shows it best)

I think you're right, it doesn't go away when the clutch is engaged so can't be gearbox. It also briefly happened today just after I started the bike with it in neutral. The clutch doesn't appear to be slipping though.

[Paul in NZ]

Is the electric start re engageing?

[actungbaby]

Na that won't happen

The gearbox will lock up, the bike will high side him and he will be so busy in hospital learning how to eat thru a tube and pee into a bag he won't worry about the bike anymore

Anyway it's harder to ride with only one leg:)

No it wont its called clutch lever i had bike lock up on me no dramas why the two stroke boys from 60,70srode with one hand over the clutch

Anyways gb 500s are not going be doing 120mph are they

[actungbaby]

Is the electric start re engageing?

yes you got it i put my spacer on the cog enages with the engine on vfr and whould not start just locked

[Nausea]

Is the electric start re engageing?

It could be that, thank you I will check it out.

[Murray]

It could be that, thank you I will check it out.

So where are we at with it?? Still reckon its the engine and best sell the engine off quick

I'll buy it!!!

;);)

[Nausea]

I haven't ridden the bike for a couple of weeks, the 'cyclone' we had last weekend meant it stayed in the shed. I will take it out for a spin tomorrow & see if I can get it to recreate the sound again.

I had the bike checked when I bought it, no worries about the engine :)

[Murray]

I haven't ridden the bike for a couple of weeks, the 'cyclone' we had last weekend meant it stayed in the shed. I will take it out for a spin tomorrow & see if I can get it to recreate the sound again.

I had the bike checked when I bought it, no worries about the engine :)

My wife has a GB400 and its a great bike but think Im going to have to do new rings, camshaft valve guides and seals and although i have a pretty good deal on doing the work i alway thought an extra 100 cc's might make a great differnce.

strangely this bike is 1 down and 5 up gears and with an oversized front sprocet goes like a wee rocket

great bikes