Proud owner of a "brand new" Maxim

[doodsaibot]

Howdy, fellas!
New to the forum. I recently purchased my first motorcycle. Behold, my "brand new" 1983 Yamaha XS400K Maxim. It has only 3,550 miles!
Like I said, it is my first bike and I fell in love with it the moment I saw it and even more so when I first rode it. It seems like the perfect bike for cruising around town and just lettin loose. But it definitely has more juice than those 250's I rode in the basic rider's course.
I have already learned quite a bit from reading through this forum and plan on learning more. Let me know what yall think about the bike. I will take more photos soon.
I am currently cleaning the carb(s)? (two carbs joined into one) for my own peace of mind. The bike was stored for a while so it is best to do so anyway.
One issue though, I noticed the rubber joints that connect to the backside of the carbs were a bit worn out. I can't find replacements for these "air cleaner joints." The joint on the left side does not form a good seal around the carb and degeneration on the right air cleaner joint is not far behind. They are both separate joints.
I don't want to have to go to pod filters. As of right now, in terms of look and performance, I want to keep everything original and standard (that may change in the near future.)
Most links I have found on this forum for spare or replacement parts do not carry the air cleaner joints. It is obviously an obsolete part but again I would like to find something to replace the joints without having to go to pods. I believe this bike is the DOHC (I can not find an owners manual to save my life) and I can't find much info on this bike in particular. Any help from yall is greatly appreciated! Thanks again!

 

[rugbywarrior89]

Welcome to the forum. That is a nice looking bike you have there. If it is a Maxim, it's definately a DOHC model. If you look at the first 3 characters of your VIN, you can match it to the following thread and find out a little more info on it. Once you've done that, you can check out the manuals to help you with every step. You don't really need an owner's manual, you have just become a member to the greatest owner's manual of all time

http://www.xs400.com/forum/showthread.php?t=4458

Also a tip for the forum. The google search on the left hand side of the screen will usually provide better results than the right side search. However, they both come in handy.

The classified section will provide many of the stock parts youare looking for. You are a rare breed to try a factory restore. I wish I could do that. Good luck and I know you will enjoy it.

 

[xschris]

Welcome to the forum. Post an ad in the classified section for the parts you need. A lot of people pull stuff off to "modify" the bike. You may get lucky.

 

[willem]

the DOHC owner's manual will work for you. The bike in the picture (seca) doesn't look like it, but it is mechanically about 95% the same as your maxim.

congrats on the nice new bike

 

[Lou Ranger]

Welcome to the Forum.
A service manual for the DOHC is downloadable from here - Garage section, item #2, post #3. It's for the SECA variation, but the maintenance items, intervals etc. are the same and the engine is the same.

For rubbers, try this outfit: http://www.jbmindustries.com/
He makes carb holders and diaphragms - not sure about intakes. You can write him to see.

After cleaning up the carbs I would put on a $3 in-line fuel filter before firing it up. You never know what will try and come down the line from a tank that's been stored.

And check out Willem's intro thread. Believe me, every item on it is useful and it pays to resist being impatient - unless you want to spend time with owner-inflicted maintenance opportunities.

http://www.xs400.com/forum/showthread.php?t=10595​

 

[doodsaibot]

Thanks for the replies, fellas. I will skim through those links y'all gave me for some additional info. It's nice to know that the SECA is similar to my bike. I think someone here in town is parting their SECA out so I may find what I need off of it. Thanks again.

 

[Donkey]

Welcome to the 1983 Maxim 400 club. I also have the same bike. Got it last fall out of a shed it was in for 11 years with 6000 miles on it. Got it going and put 3000 on this summer.
I do have the original owners manual and it just has the basics. If there is anything you need looked up in it let me know.

 

[doodsaibot]

Thanks, Donkey. It is a pretty cool ride! I just got mine back up and running again after cleaning the carbs. It's having some issues here and there but I think I can manage it. I have scoured the web for an owner's manual. They sure are hard to come by. Any way, I will most definitely keep that in mind, brother. Stay safe!

 

[doodsaibot]

So, I have been searching for some new tires for the maxim. There are so many to choose from that I don't what to pick. Any suggestions? Donkey, what do you have on yours? Sorry my photo is sideways.

 

[doodsaibot]

Took her for a nice evening ride the other night. She did well. I am in love with this bike!

 

[MNovotna]

Hi, Welcome!
I'm new myself and part of the '83 club.
Mine, like yours, is all original parts and had 2,200k on it. Well maintained.
Just did a 5,000k+ tour around east-coast Canada a couple of weeks ago and it was the newer Honda my husband rode that had any issues. My maxim chugged along as if it was new off the shelf.
Which, it kind of is

 

[Donkey]

So, I have been searching for some new tires for the maxim. There are so many to choose from that I don't what to pick. Any suggestions? Donkey, what do you have on yours? Sorry my photo is sideways.

Sorry so late have not been on in a while. Also not riding due to rain. Rode it to work today and got your info.

The front I put on this year and had to go with a 3.25 19. I chose my tire by the tread to be as close to stock appearance as possible.

The rear I will be buying next spring. Right now it is a 130/90 16.

 

[doodsaibot]

Hi, Welcome!
I'm new myself and part of the '83 club.
Mine, like yours, is all original parts and had 2,200k on it. Well maintained.
Just did a 5,000k+ tour around east-coast Canada a couple of weeks ago and it was the newer Honda my husband rode that had any issues. My maxim chugged along as if it was new off the shelf.
Which, it kind of is

Very awesome, MNovotna! Sounds like yall had quite the adventure! I am looking forward to making a trip around the hill country here in Texas very soon. Did yall get any good photos on the trip? I heard its amazing up there this time of year.

 

[doodsaibot]

Sorry so late have not been on in a while. Also not riding due to rain. Rode it to work today and got your info.

The front I put on this year and had to go with a 3.25 19. I chose my tire by the tread to be as close to stock appearance as possible.

The rear I will be buying next spring. Right now it is a 130/90 16.

Very cool, Donkey. Those are the same sizes I have on my ride right now. I am going to be selecting the Kenda Challengers for my Maxim. They seem to be a popular choice amongst other Maxim and XS400 riders. They are also a fairly decent price.
By the way, is there anything in the owner's manual about the warm period for the Maxim? My warm ups seem to take quite a while and I am wondering if I need to investigate something else.

 

[Lou Ranger]

... By the way, is there anything in the owner's manual about the warm period for the Maxim? My warm ups seem to take quite a while and I am wondering if I need to investigate something else.

Mine was always fussy about starting on a real cold morning or after sitting for several days. But even on those occasions, once it fired up, I could ride it off gently withing 30 seconds on partial enricher, and then push the enricher in within the first mile or so.

Something is amiss if it stalls or stumbles under a light load after warming up for a full minute. By light load I mean riding it gently out to the main road on partial enricher (about a mile in my case).

 

[doodsaibot]

Mine was always fussy about starting on a real cold morning or after sitting for several days. But even on those occasions, once it fired up, I could ride it off gently withing 30 seconds on partial enricher, and then push the enricher in within the first mile or so.

Something is amiss if it stalls or stumbles under a light load after warming up for a full minute. By light load I mean riding it gently out to the main road on partial enricher (about a mile in my case).

Yeah, the last couple of nights have seemed like it has taken a bit longer than normal. I start her up at full enricher and after the RPMs start to climb I click it over to about half enricher and let it hover around 2K. I then take her down the road about a quarter mile and do some circuits in an empty parking lot till I can click the enricher off. It has also been just slightly cooler outside the last week or two but not by much. So I am not sure if that is what is effecting it. I have my normal idle (without enricher) set at 1200 RPM.

I will take her for a spin here in a while and see what I can come up with.

 

[doodsaibot]

Well, I took her out for a spin. Rode about 35 miles or so. I did notice that I had to tweak the idle screw after the bike was completely warmed up. I have had to mess with that screw the past few days including today. Would ambient temps have anything to do with that? After I have the idle set, though, it runs just fine. I can bet that tomorrow if I were to ride I would have to reset the screw again after it warms up.

 

[16VGTIDave]

You shouldn't have to mess with the idle speed. The different idle speeds on different days you are observing are a symptom of another issue. Dirty carbs, lean idle mixture, carbs not synced, etc.

You should also be aware that these carb adjustments should be set with the engine up to operating temp, which requires 10 to 30 minutes of reasonably aggressive riding depending on ambient temperature. Cruising around won't get the engine to operating temp. Neither will idling. By operating temp I mean the oil has to get up to about 80C (180F). Believe me when I tell you that DOHC's run cool. I rarely see oil temps above 100C (212F) unless I've been riding on a highway at 120kph (75mph) and come to an immediate stop. When cruising on 22C (72F) days, I rarely see oil temps above 70C (160F).

I'd suggest you get the idle mixture adjusted correctly, then sync the carbs and see how it runs from day to day. And for the love of [whatever you consider holy], don't ask "how many turns of the pilot screws?"! Counting turns is the wrong way to adjust the idle mixture. The number of turns is to get the bike running (2 from seated), or to determine if your bike needs different sized pilot jets (more than 4 to get a good idle).

 

[doodsaibot]

Sounds good, Dave. That's interesting that these Maxims run a bit cooler than the SOHC bikes and it is making a lot of sense to me now. I am going to check out that idle mixture screw and watch that video on making my own manometer.

At first I wasn't used to the high rev sound this bike made. For a bout a week and a half, I was riding it like a cruiser (because it looks like one) until I looked closely at the redline on the tach. I really opened it up and was surprised when the bike just roared to life around 6k and upwards to 8! I was not initially used to that sound but now I am in love with it. I even hear it in my sleep.

 

[xschris]

Oil temps and head temps are very different. With my sohc bikes I see head temps around 265*f during summer driving temps and oil about 170*f. If I really rip on it they will go up another 15* or so but that's it.