My Maxim is driving me crazy, maybe it is time to give up.

I guess I should start from the beginning, sorry but this post will be a long one.
Last fall I was looking for a bike. I decided I wanted something older since I like that style. My brother in law had a 750 Maxim sitting in his car port. He had rode the bike for two summers when the carbs started acting up he parked it. It sat for a year and he bought a new bike. His wife said the bike had to go and he called me and told me if I wanted it I could have it. How could I say no to that? Tonight I wish I had said no.

Anyway I got the bike home and removed the tank. The petcock was removed from the tank and the carbs were drained by the PO when he parked it. Well I removed the carbs to clean them and noticed the air box was cracked from where the bike had suffered a fall. Since I did not want to pull the motor to swap in an air box I added pods, cleaned the carbs, rejetted, and bench synced the carbs. Put them back on and reinstalled the tank and petcock. Started the bike and she idled like a dream and picked up nicely, but the petcock was leaking a bit. I ran the bike down the road an back and it ran great, picked up nicely and returned to idle like a champ. While on that ride the gas tank started leaking from the front left corner. I brought the bike home and removed and drained the tank and found a small hole in it. Decided to drain the carbs and not mess with the bike till it got warm again.

Well it got warm again and I decided to get the bike back on it's feet. I fixed the tank, rebuilt the petcock, replaced the fuel line, vacuum line, coke cable, throttle cable, and handle bars. I also changed the oil and rear end fluid since I had not changed it since I got the bike (and from the looks of it the PO never did either).

Now this is the point at which everything went wrong. I went to restart the bike for the first time this season. A little bit of choke and it started right up but it did not want to idle. I finally figured out the problem, low voltage was the problem, it would run and idle fine while hooked to a charger, but unhook it and it would die. So I picked up a new battery today and put it in the bike. Now it will not idle no matter what. The choke must be used to start it (and it is hard to start) and once started it will not idle at the 1000 rpm mark like it would yesterday. I have to keep the choke on which makes it idle at about 4k rpms or turn off the choke and use the throttle (which will let it drop down to 2000 rpms, any lower and it stumbles and dies.)

Now is the point at which things get worse. Since changing the oil once the bike gets warmed up the starter does not want to stay engaged. I am guessing this is because the clutch needs cleaned since it no longer has the super thick old oil in there to make it work. I fought it for almost an hour today trying to get the bike to restart and the starter would not stay engaged long enough to turn the engine over just once. I do not want to pull the motor, which it looks like I am going to have to do if this starter does not straighten out.

If anyone has any advice, I would love to hear it and would really appreciate it. I have a trailer behind the garage with a bunch of scrap (old body panels, motors and parts, manifolds, and other scrap metal parts) from where I cleaned out the garage and storage building. I am just about ready to throw this bike on top the pile and take it to the scrap heap. I am tired of working on it every evening and making no head way, so hopefully some one here can shed some insight and help on getting this thing running again.

Thank you for hearing me out and any help you can give, sorry for the long winded post.

 

sorry to hear about that prime. i was in the same problem with a kz750 once. if you got the bike for free just take your time. patience is a virtue.

 

This may help on the starter issue, if indeed it is the clutch:


STARTER MOTOR CLUTCH REBUILD PARTS:

sms6) OEM and aftermarket parts to rebuild your STARTER MOTOR CLUTCH DRIVE. Yamaha used a "centrifugal clutch" type of drive system to engage and disengage the starter motor drive from the engine gear, and over time the springs, spring caps, and dowel pins that provide the engagement action can fail....which is terrible, as these are a real pain to replace, and almost always require dis-assembly of the upper and lower engine cases.

However, there are a few alternative methods that might (or might not) save you some incredible effort and allow you to "dodge a bullet" and repair your starter clutch system in an easier manner; but, the success of such methods really depends upon whether the clutch failure is due to mechanical wear or damage to the pins, caps, or springs (in which case, you MUST somehow get in there and replace those items), or, if the caps and pins are merely "seized" in the starter clutch hub due to accumulated varnish and sludge, etc.----and in such a situation, then you might be able to clean out the mess and restore the clutch to an operational condition.

Methods a) and b) below address the problem of "sludge-seized" component pieces. Method c) deals with the problem of damaged parts. Note that if any of the major components are damaged---the clutch hub, or any idle gears or sprockets---then the engine is going to have to come out and taken apart to allow access to such larger pieces.


a) Pull the starter motor, and shoot lots of solvent (seafoam, carb or brake cleaner, etc.) directly onto the Starter Clutch Assembly.

Then, drain all of your engine oil and refill with fresh oil. Run the engine while on the centerstand until it's warmed up, drain the oil again, and fill with fresh oil.

If the starter clutch was just sticking, this method may wash away enough of the accumulated gunk and set you on your way.


b) Next, it may be necessary to actually run a solvent in with the engine oil in an attempt to loosen any engine oil sludge that has accumulated over time, and locked the starter clutch pins. Of course, such solvent should be run in the engine with the bike on the centerstand, and not any under load!!! Then drain and flush this solvent-and-oil mixture, refill with fresh oil-only, run on the centerstand again, and then drain and refill with fresh oil-only again......now you can ride it again. You want to make DARNED SURE that you get all of the solvent-saturated oil out of the crankcase before you put the engine under load, and risk chewing up engine bearings, etc. with solvent-thinned oil!


ALSO, TAKE NOTE OF THIS EXPERIENCE FROM ANOTHER XJ-OWNER:

"If there is not enough grip between the plunger and the roller, it can skip, causing the grinding, clacking noises you hear. I have been told by a Yamaha mechanic with over 20 years experience that it is very possible for some synthetics to greatly increase the chances that this will occur......"

So this weekend I drained the synthetic out, put some cheap 20W50 in, and rode it for a little while. Then I drained the cheap oil out and put Castrol GTX 20W50 in and the starter does not malfunction anymore, not even once! I cant believe it! I guess these bikes were not made to run synthetic---I'm sticking with conventional oil from now on."


c) If none of the above solutions work, then it might be time to do the dirty deed. Some people claim to have successfully accomplished a "Hail Mary" replacement of the starter clutch pins, springs, and caps with the engine together, but more than likely the engine has to come out of the frame and being dis-assembled to access this area. If you read this thread:

http://www.xjbikes.com/Forums/viewtopic/t=1700.html

you'll get a good idea of what challenges you're up against.


By the way, if you do decide to split the engine open and perform open-heart surgery, you might as well replace the primary chain and guide while you're in there, as those are also "wear items" and will cause problems if and when they start failing!

 

Re: My Maxim is driving me crazy, maybe it is time to give u

Never give up!! If the bike sat for a while during the winter then the carbs may be gunked up again and need to be cleaned. Also make sure your valve clearances are within spec. Could be a vacuum leak in the carbs causing the need for enrichment. I had a similar problem with my 650 carbs. Not sure about the starter though. I'm sure there's someone out there who knows. Hope this helps and try not to get too discouraged. easier said than done I know.

 

What kind of oil did you put in??

 

I had this exact, and I mean EXACT problem only weeks ago.

PULL YOUR CARBS.
They need to be cleaned and checked for damaged rubber parts.

I know I know, doesn't make sense this has to do with the starter.
Well, here is why it does.

That GUNK chacal talks about, well it's bad on mine apparently.
But running the motor daily or bi-daily should loosen it up.

Can't do that if you can't get it running.

Here is what happens... it sounds like sitting all winter your carbs got gunked up. I was running carb cleaner in my gas, which loosened my 'gunk' and plugged my carbs over time. As they got plugged, with the motor struggling each time to start right, the clutch started slipping on the 'gunk' in the clutch.

Now that I got the carbs cleaned and the motor running right, at least baseline, it fires right up, no slips. Haven't heard it since.

Do not give up brotha'.
Trust me, ask the others here.

I came so close, SO many times in the last month.
It is not worth it. Especially for a free bike!

If you are frustrated, let it lie. But not in that pile.
When you are ready, hit it up again. You'll be glad you kept it.

And as MN is suggesting - synthetic oil can cause this symptom.

Don't give up!
I have many long winded posts on here, stating I am ready to throw in the towel. And as I slowly get it back together, running better (She's on the road now, but still needs floats checked and new sync/colortune) I get happier every day. Every thing I do to it makes me feel better, and happier I kept it.

The bikes 25+ years old, give it some slack, and some time, and it will give back.

Good luck.

 

Seriously dude!
The key is it was running great not too long ago - by your own description!

It's a small bit of faith then to assume you can get her running again.
A lot of folks on this forum get a truly dead bike and keep chugging on the hope that there is life left in it.

Stick to it. These bikes are great, but tricky. One of the many great posters on this forum will have that one piece of advice you'll need.

 

Thank you for the support, I will keep plugging on, just sometimes it gets frustrating.

chacal: Thank you for that info!!! I will give that a try tonight. 8)

MN-Maxims: I put Rotella 20W40 in it. I would have used the 20W50, but no one around me had any in stock.

Also from the consensus it looks like I need to pull the carbs again. I cleaned them last winter, surgical clean and it ran good Sunday evening, just yesterday it all went belly up

 

It sounds to me like you may need to get an inline fuel filter installed sometime AFTER you clean the carbs again but BEFORE you run it too much again.

I would run just good old conventional 20W50 Castrol or Havoline for a while and see what happens with the starter clutch.

 

OK so RickOMatic talked about running 20w50... calling it racing oil, and saying to add a bit more than normal (make the bubble go away) because it is thicker are harder to move.

Everyone jumped saying it is way too thick blah blah blah.

Now I see others running it... O_O

What's the deal?

 

Re: My Maxim is driving me crazy, maybe it is time to give u

I only used 20w/50 in very hot conditions. Here it gets very hot and humid in the summer and that oil holds up better and resists thermal breakdown. I am going with 15w/40 right now, good stuff. I used the Rotella brand and it shifts like a dream.

 

Thanks for the tip Chacal, the Sea Foam worked great and the starter catches now, even when the bike is hot.

bigfitz52: I do have a fuel filter in it.

Now if I can just get the thing to idle I will be set.

 

have you checked your idle mixtures? after sitting for a long period of time, and getting a thorough cleaning, you may run into a mixture issue.