Honda Twins banner

1 - 20 of 38 Posts

·
Registered
Joined
·
224 Posts
Discussion Starter · #1 ·
Quick question.

Im considering taking a GS750 in on a trade. I asked if the bike ran and if it smokes. The guy says just on cold startup with the choke on. Says it quits after you turn the choke off. That sound right to you guys? Bike has 15,000 miles on it, was ridden up till the end of this season and is stored for the winter. Bike is in Ohio.

Thanks Guys!!
Henry
 

Attachments

·
Premium Member
Joined
·
771 Posts
He's implying it's getting overchoked. Sounds plausible.

However, in general:

Black smoke = too rich. That's what this could be, if the smoke is black
Blue smoke = burning oil.

Blue smoke on startup = bad valve guide seals. Oil leaks past valves and burns on startup. Typically goes away as engine warms. That's what this could be, too, if the smoke is blue.

Blue smoke while running = bad rings (worn bore, etc).


Volumes have been written on the various forums about the big GS's in general. Great bikes with a (very) few known, fixable weaknesses.

Kirk
 

·
Registered
Joined
·
224 Posts
Discussion Starter · #3 ·
kirkn said:
He's implying it's getting overchoked. Sounds plausible.

However, in general:

Black smoke = too rich. That's what this could be, if the smoke is black
Blue smoke = burning oil.

Blue smoke on startup = bad valve guide seals. Oil leaks past valves and burns on startup. Typically goes away as engine warms. That's what this could be, too, if the smoke is blue.

Blue smoke while running = bad rings (worn bore, etc).

Kirk,
Thanks for the super quick reply! Knew somebody would! Man did say it quits after choke is released (could be warm too). So, probably okay, worse case valve seals, hopefully! Ill ask about color of smoke. How much of a pain is it to replace valve seals? Like replacing a cars? Been there done that, thats not that big of a deal. If not, is it a pain?

Thats the problem with 400 miles between me and traders bike!

Henry
 

·
Premium Member
Joined
·
771 Posts
Dunno about valve guide seals on the GS's. I've done it on little vintage Honda singles and it's easy as pie - pull valve springs, pop the old seal off, pop the new one on, replace springs.

On the DOHC's, you probably have to pull the cams out of the way, but I'm guessing that's about it.

Kirk
 

·
Registered
Joined
·
6,495 Posts
Henryinva said:
Bird76Mojo said:
FLY-N-RIDE!!!! She'll make it..

GB :mrgreen:
He's bringing it.....were making a swap for an old car I have that he wants...just dont want a big headache bike....

Henry
Name an old bike that is not a big headache??
 

·
Sensei
Joined
·
27,164 Posts
I BELIEVE tose have shim and bucket valve adjustment, and you DO have to pull cams (2)........Shim adjusters are a PAIN!......
 

·
Registered
Joined
·
224 Posts
Discussion Starter · #9 ·
tbpmusic said:
Henryinva said:
Bird76Mojo said:
FLY-N-RIDE!!!! She'll make it..

GB :mrgreen:
He's bringing it.....were making a swap for an old car I have that he wants...just dont want a big headache bike....

Henry
Name an old bike that is not a big headache??
Leave it to Bill to throw a reality check in there!

Henry
 

·
Registered
Joined
·
224 Posts
Discussion Starter · #11 ·
Henryinva said:
66Sprint said:
I BELIEVE tose have shim and bucket valve adjustment, and you DO have to pull cams (2)........Shim adjusters are a PAIN!......

Thanks guys, trying to make an inteligent decision here and your input is appreciated!!

Henry
Dont know about how inteligent a decision it was, but it'll be at the house in a week and a half. Asked about the smoke, says its blue but quits after a couple of minutes warmup. Its not his bike, its his dads and the kid isnt familiar with bikes. So, worse case is probably valve seals..

Henry
 

·
Premium Member
Joined
·
2,148 Posts
Its probably valve seals, just got old and hard so don't seal right anymore ( could also be wrong oil, using car stuff instead of 10W/40SG/SF.
Try some Shell Rotella 15W/40 in it
It's a shim over bucket valve adjustment.
There is a special tool to depress bucket to change shims. I have a boatload of shims for them but I'm in Florida and stuff is stored in Britain (actually, I think my brother may have 'appropriated' them for his GS1000?)
I love them because they are the easiest valve adjustment's I've ever done. (yes, is MUCH easier than screw and locknut and way easier than CB350 eccentrics)
The hardest part is getting the 18 (or 20? I forget) bolts out of cam cover.( take the chrome covers off end first, gives yoiu more 'wiggle room'
They run a tight clearance to keep top end noise down (0.001"~0.003")
You'll have to pull head to change them though, too easy to damage bucket bores otherwise.
I would run it first, check oil level, maybe do oil change and clean carbs/re-set float heights before tearing into motor
PJ
 

·
Registered
Joined
·
224 Posts
Discussion Starter · #14 ·
Henryinva said:
Thanks PJ, Bike is supposed to show up here sometime today. Well see what this guys definition of smokes a "little" on first starting up means! :roll:
I'll let you guys know what the deal is...

Thanks again!
Henry
WOOOOOOOHOOOOOOOOO!!!!!!

Smokes a little, I CANT EVEN SEE IT!!!!!!! Must have smoked a "little" when he fired it up after sitting since last summer, but I fired it up when he got here and there was ZERO smoke other than white condensation for a few minutes.....This is a happy camper here!
Got to give it a bath as it looks like hell, but I'll post some pics here after a bit....

Henry
 

·
Registered
Joined
·
210 Posts
You're going to like that bike Henry, I worked in a Suzuki dealership in the early 80's and those things a re bulletproof!
 

·
Registered
Joined
·
224 Posts
Discussion Starter · #16 ·
Yeah John, I think your right! The thing sounds bad as all get out. Need to find a 4into1 for it! My CB's getting jealous allready! I stuffed it into the garage and parked it. I need to finish the CB first. But I have the corner of my eye on it! (A little incentive to finish).
Well, Heres a pic or two of the latest addition to the garage.

Henry
[attachment=1:2lnn2xvi]gs750 2-7-09 006.jpg[/attachment:2lnn2xvi]
[attachment=0:2lnn2xvi]gs750 2-7-09 005.jpg[/attachment:2lnn2xvi]
 

Attachments

·
Registered
Joined
·
210 Posts
Looks good Henry, a new seat cover and a little clean up and it will look like new. Looks like a 78 model, spoke wheels and single disc on the front. In the early 80's the shop I worked for had a 78 that we used for endurance racing. We raced that thing for 2 full years in probably a total of over 100 hours of race time and never did anything to the engine except check valve clearances and change oil. We finally replaced it with a GS1000 but it still ran perfect. Like I said earlier, bullet proof. At that time we were a Suzuki, Yamaha, Triumph dealer and we imported a couple of Paul Dunstall special GS1000's and I bought 1 of them. It was a great bike and very fast for the time. I was clocked a 156 MPH on a practice day at the local race track on it. Here's a pic taken back in the day. Still one of my favorite bikes.

 

·
Premium Member
Joined
·
2,386 Posts
My brother had a '78 that I raced, bone stock, in the Production class for one year. I thought the '78's were the first year for the mag wheel. I know the '76's had the single disc with spokes and the '77's came with dual disc's and spokes.

This is from memory and that is suspect these days.

That is a great find though, congratulations. I'd leave it stock. As John said, the motors were bullet proof and they made a great street bike. I'd love to find one it that condition myself.
 

·
Premium Member
Joined
·
2,386 Posts
As I think about it, the Dunstall was a great looking bike but nothing more than a bikini fairing, a paint job and an 18" wheel you could always do a 'Cooley Replica GS1000S' look. The 1000s had mag wheels but I don't think the spoked wheels would take away from it much.
 
1 - 20 of 38 Posts
Top