Bought a Maxim, bunch of questions

Hey, I just picked up a 1982 XJ750 Maxim as my second bike after a few years without one. I'm slowly getting the hang of it again, but I have a whole bunch of small questions:

1) When I ride over speed bumps (very, very slowly) it feels like the bike bottoms out and hits the bump when the front wheel comes down. I can't tell if I'm making contact with the bump or bottoming out the shocks. Do I need to do something to the front suspension?

2) When the bike is cold, it won't budge an inch while in gear with the clutch pulled in. It glides freely in neutral. I know there should be some resistance with a cold wet clutch, but is that normal?

3) I assume it's an aftermarket exhaust, it's 4-into-1 and I think these were 4-to-2 stock? It has no baffles, and it is painfully loud. I need to get the volume way down since I live in an apartment complex and like my neighbors. Since I know nothing about what's on it and the sections are welded, is my best bet a full new system? Any recommendations? I'm liking the reviews on this one.

Thanks!

 

no expert but here's my 2 cents
1) put some paint on the bump you feel this on, then go back and see if you scratched some paint
2)the bike shouldn't move At All while in gear, clutch in, and cold. shouldn't want to move either, unless it was sitting for 8 or more months and the clutch plates were sticking together, but the first time they break free, that's it, they're free
3)if the bike is running nice now there's a chance it was jetted for the 4 into 1 exhaust. does it have an airbox? is there a lid on the airbox? and lastly, do you know how to jet? you'll want to avoid jetting if you're not mechanically inclined. maybe you can get a more restricted 4 into 1 but there's Never going to be a gaurantee you won't need to re-jet. maybe you can read us the #'s on the jets inside the carbs and we'll tell you if they're stock or not
Oh, welcome to the site. I knwo you wrote the bike model and year in your post but for future posts it'll be good to have the bike in your signature

 

Er, I have an air filter... I guess I don't know what you mean by an air box. As far as I can tell, it doesn't have the big plastic air chamber that my CBR had.

I don't currently have a garage or else I'd learn how to rejet myself. For now I'll just have a shop do it if it needs it. With the current setup, it pops pretty loud on deceleration, but other than that I don't notice anything horrible.

 

ok no problem. how did you find the air filter, did you have to lift the seat and then remove a black plastic cover to see it? if so you have an airbox. If you can see the airfilter(s) from the side(s) of the bike (wihtout lifting the seat) you have No air box

 

First off, before you ride it any more, check the back brake for shoe delamination; it's a common issue on these bikes and can drop you on your ear without warning.

Popping on decel indicates a lean condition.

I would give up on that "have a shop do it" notion. IF you even find one that will touch one of these bikes, there's a good chance they won't do it right and an equally good chance they'll screw it up worse. And charge you a bucket of money to do it.

A 30-year old bike is a DIY proposition, unless you have wads o'cash.

 

mrmekon, first of all welcome! If you take full advantage of this forum you will be able to DIY most things on your bike, that is if you have a bit of previous mechanical knowledge.

Second of all, to answer your question about bottoming out I have a few questions for you:

1) Have you checked your tire pressure lately?
2) Do you have a center stand? Mine has bottomed out a few unexpected times.
3) Are your shocks properly adjusted? If they are in good condition, on an '82 XJ750, front shock dampeners should be set to 1 or 2 and rear shocks should be set A through C all according to taste.

 

I haven't removed it yet, but it looks like the air filter is bolted in under the seat, and not visible from the outside.

The brake delamination thing has me panicking. I'll pull the rear tire and check! I was going to ride it in to a shop to get new tires (definitely can't mount those at home), but if I'm already taking one wheel off maybe it's safer to take them both off and just take the wheels in.

Does the brake delamination only happen with the original pads, or is this something to check periodically even with replacements?

Zyggy:
1) Tire pressure is good, though tires are not (dangerously bald). I inflated them and tested a few days later to make sure it held.
2) I realized on the way home that that's probably exactly what's happening, I think the center stand is hitting.
3) I have no idea how to adjust the shocks yet, I need to look into that.

 

1982 Bike.
You need the 2010 Upgrade.

Front Fork Overhaul:
New Front Fork Springs.
Sliders and Seals.
Get a Book.

Front Brakes:
Caliper Overhaul
Caliper Seals
Get a Book.

Steering Headset Bearings
Remove Balls and Races
Install Roller or Sealed Roller

Carburetors
Cleaned; Bores Polished

Valves Adjusted

Get a Workshop Manual.
Preferably a Yamaha Workshop Manual.

An illegally pirated, unlicensed, Copyright Violated set of Yamaha
Manuals is also available if you don't mind risking going to Prison.

 

Don't panick, (check my sig and you'll see why I can say this). It is a really easy fix that you can do while the shop mounts the new rubber for you.

I don't know if it happens with aftermarket brakes, but if it takes 20+ years to show up some one else will probably own it by then. (I'm pretty sure its an old brake phenomena.)

Welcome,

Ken

 

It happens with the old shoes; new ones are fine. It's a result of sitting, and is apparently VERY common.

Read how common: http://xjbikes.com/Forums/viewtopic/t=15874.html

It's a lot cheaper to get new tires put on if you just take them the wheels anyway.

 

hey- what is your 4-1 like? if its chrome and in OK shape... I have an xj750 SECA stock exhaust... i know the headers and collector box will fit perfectly... the cans should fit.

pm me if you're interested.

 

WOW i guess i'll need the 2010 upgrade aswell since mine is an 80 XJ650.

 

This "2010 Upgrade" sounds a bit much... I'll do that as necessary. This thing wasn't sitting in a barn, someone has been riding it and taking general care of it.

I have a Haynes manual and I'm not afraid to use it, I just don't have a very convenient garage.

Is it safe to 'check' the rear shoes, or should I really just replace them regardless? It seems like they still have more than half of their tread, at least if that gauge on the outside is correct, but no clue how old they are. They front pads also have tons of pad left, so I'm confident they have been replaced.

 

Back brake delamination can lock the brakes. I would just replace them. Check my signature to find out why...

 

for me it's a $30 piece of mind...

 

Yep, I was just wondering if there's any way to know. I already have some rear shoes on order and a new Mac 4-1 exhaust system... I think I'm going to also pull the trigger on front pads and SS brake lines from Chacal, but not completely convinced I should do that to my wallet... but these brakes suck compared to my old CBR600, and god only knows how old the rubber and fluid is.