Play in the front forks of my new 83 GS750E

[83GS750E]

Well, I finally got her running properly, went out for the inaugural ride today and it felt like I had some play in the head bearing. On further diagnosis the play is actually in the front forks (both have some play) and you can feel it when going over light bumps as well as when you apply forward pressure to the front forks with the brake on when you are stopped. So my question is twofold: What is involved in reducing this play, is it as simple as refilling the shocks with air? The sticker on the side says the recommended pressure is 36 psi and I would presume it is less than that after having sat for at least a year. If not, and it is a matter of rebuilding the front forks or something to that effect, how urgent is this? Should I be riding the bike at all or is it okay as long as I take it easy (I would have to ride it about 40km to do any major repairs as I live in a condo and they probably wouldn't appreciate having my forks laying all over the parking lot). I appreciate everyone's help in getting this thing running properly and I look forward to getting to the bottom of this latest issue.

[reddirtrider]

What do you mean by play in the forks - up and down or side to side?

If you put in 36 psi to those forks you'll probably blow a seal. They should hold air, but use a bicycle pump and put in 6 or so and see if it holds.

[83GS750E]

The play is like a clunking sound when you're going over bumps. It's definitely lateral (side to side and front to back) movement, although it does it a little bit when you compress the forks. Generally speaking it's a looseness in the front end and feels like a head bearing.

[silverhorse47]

How many miles are on this bike, and have have you raised the front of the bike off the ground, extended the forks and filled them properly with fluid?
At the time you do this, please also torque, and at least re grease, the head bearing.
If you do these things you can check all the moving parts at the same time, and decide if you want to risk killing yourself or not, depending on the results.
:-)
S.

[tfb]

If there is excessive lateral play in the forks, you will probably need to replace the two bushes inside each fork. They are part no's 7 and 10 in the piccy below (which is from the AlphaSports website):



Bear in mind, though, that if the outer tube (aka lower fork leg) is itself worn internally, then some lateral play will remain, even with new bushes.

[Billy Ricks]

Do the bushings and while you're at it replace the springs with Progressives so you don't have to run air at all. Mine always leaked down in short time so you had to keep a constant eye on pressure. Flush the entire assembly four or five times with kerosene or diesel to clean the internals. Pump the fork to run the solvent through the system. Then let them stand upside down for a bit to drain. To replace bushings you have to tear the fork down. It's an easy job that can be done in an afternoon.

If you want to run air go with about 8 lbs. With the condition of your fork it probably won't hold air though.

[reddirtrider]

Do the bushings and while you're at it replace the springs with Progressives so you don't have to run air at all. Mine always leaked down in short time so you had to keep a constant eye on pressure. Flush the entire assembly four or five times with kerosene or diesel to clean the internals. Pump the fork to run the solvent through the system. Then let them stand upside down for a bit to drain. To replace bushings you have to tear the fork down. It's an easy job that can be done in an afternoon.

If you want to run air go with about 8 lbs. With the condition of your fork it probably won't hold air though.

Do what Billy's suggesting.

On a side note, my 750ES's forks have springs in them that look like Progressives. Did Suzuki install stock springs in these bikes that were wound tighter at one end?

[Billy Ricks]

Do what Billy's suggesting.

On a side note, my 750ES's forks have springs in them that look like Progressives. Did Suzuki install stock springs in these bikes that were wound tighter at one end?

IIRC they were. If you don't have a spacer under the cap they are probably still stock.

[bonanzadave]

Did Suzuki install stock springs in these bikes that were wound tighter at one end?

Yes, mine were. Stock spring - Top. Progressive - Bottom

[reddirtrider]

Yes, mine were. Stock spring - Top. Progressive - Bottom

Ok, now next question. Did you guys block off the anti-dive when using Progressives? I'm planning on using the anti-dive for the first few rides after the rebuild to see if I like it. I've never had it before.

This isn't my bike BTW. It's my son's. It seems I'm the cheapest mechanic he knows.

[tfb]

It's an easy job that can be done in an afternoon.

Maybe so, but I found that replacing the bush (# 10 in the diagram) an absolute pain in the rear. Getting the old ones out was fraught with difficulty, they were such a tight fit into the lower fork leg.

I ended up having to use a shortened hacksaw blade, and carefully cut through the bush. Not my favourite bike maintenance memory...

[silverhorse47]

I agree this is an easy repair. There is no need for a hacksaw to remove or replace the 'bush' or 'metal'. It is a split teflon coated bushing.
If there is a clunk, the head bearing would have to be way loose, or there is not much fluid in the forks.
If you do not have a service manual, get one, and rebuild the forks. Dismantle the antidive, if you must, and install good springs and possibly cartridge emulators. If you are not then happy, go for a newer front end.
Simon has the word doc on rebuilding the front forks. I know nothing about it.
good luck,
S.

[83GS750E]

Thanks, I've got the forks apart right now, just waiting on new bushings and oil seals, should be about a week. Any suggestions for when I start putting them back together?

[handkphil]

I've got the mystery fork clunk too

Hmmm...the forks on my 1982 GS750E have the same "play" that results in a clunk when I go over small to medium bumps at slow to medium speeds. I've been wracking my brain trying to figure out what it might be. I've checked all the bolts, and everything seems to be tight.

It's been this way since I bought the bike a few years ago - with just over 800 miles on it. It now has 2200 miles on it. You read that right - the bike has 2200 miles on it, not 22,000. This makes me think that it's not a worn bushing issue. I had a motorcycle mechanic replace my original springs (which had compressed from sitting for 24 years) with Progressives about three years ago. I didn't check his work, but he asked me how much fork oil to put in, I looked it up and told him, and he said he filled them. He asked me about the clunk in the forks at that time, and I replied that I had hoped he could tell me what was wrong, but he obviously couldn't.

There are no shimmies or otherwise unusual handling issues with the bike, at any speed, so I almost doubt it's a head bearing issue.

Anyone else have any theories? I'm not much of a mechanic. I'm thinking of taking it to a suspension place to have it checked out, and I think I'll ask them to block off my anti-dive and bleed my brakes while they're at it.

[83GS750E]

I didn't think they had anti-dive until 1983.