1980 Maxim runs but won't go!

What's up? This is my first post here.

A coworker gave me a 1980 maxim a while ago. It didn't run. It's been sitting around for a while and my neihbor just got his licence. He's 20 years old and in college. I told him I'd give him the bike if he help me put it back together.

Problem 1:
So it's back together now. It starts and runs if the choke is on. If the throttle is revved quickly the motor dies (or at least comes close). What are possible causes of this?

Problem 2: I'm able to let the clutch out all the way while the bike is in gear without giving it throttle(idleing). I can hold the bike from moving just just my feet on the ground. Does this mean I need a new clutch. I can also get the bike going very slow in first but as soon as I give it any gas it dies. Does anyone have any ideas? It's driving us nuts.

 

Sounds like a rich mix - are you letting the bike warm up enough before trying to lessen the "choke"?

If it sat for a while - you probably need to clean the carbs up.

 

Need to make sure you have some freeplay in the clutch lever, adjust the cable there at the lever. It may be too tight and not letting the clutch engage.

 

Thanks for the help guys. Does anyone else have any ideas?

Here's a pic of how I got the bike.
http://www.geocities.com/dmdiem/maxim/MaximOriginal.JPG


Here's one after cleaning, painting, new bars, shaving the rear fender. Still need a new seat, make a bracket for the new tail light and oh yeah, get this thing to work....

http://www.geocities.com/dmdiem/maxim/MaximPaint.JPG

 

Did you have the carbs apart?
what did you find? need to kno to help out.

Sounds like the clutch adjustment is too tight.

 

wow you turned a kawaski into a yamaha?

 

Like HVNBND said we need to know if you worked on the carbs. I also would like to know if it will idle when warm with the choke off. If it won't then most likely your idle jets are clogged.

 

I adjusted the clutch cable and it seems better. Now when this thing is idleing(with the choke on) i can let out the clutch and ride it around but as soon as i give it gas it dies.

 

Still don't have the facts we asked for. But..... if it will not idle without the choke Even if Warm then it isn't getting fuel with the choke off. Clogged idle jets or pilot mixture set too lean.

 

Did those Carbs get 100% Cleaned and now you need tuning ... or, do the Carbs need to come-off and be cleaned ... because they're clogged a little and are causing the bike to quit when you open the throttle?

 

when i got the bike the carbs were off. the guy i got it from said they were cleaned so i assumed they were. maybe not. i'll pull them off this weekend and try to clean them.

 

Guess who's a genius. Yeah me, I didn't hook up the vaccum line from the intake manifold to the petcock. It runs better and I can drive it but it is still hesitant just starting off but once the rpms get up alittle it's ok. the choke still has to be on. If i can't fiddle with the carb settings and get it going good then i'll put the carbs off and try cleaning them.

Also, does the seal on the intake side of the carb have to be good? i have hose clamps on the engine side of the carbs but not on the intake side. could that be a problem?

 

Yep that could be a problem if it is leaking. It needs to get air from the pressurized airbox. If not just for the sake of it running well then for the sake of getting FILTERED air into your carbs! But an air leak there will cause problems.

 

About 2 weeks ago my bike started doin the same thing, it runs well on choke, but with no choke and throttle it putts and dies, unless the rpms are high enough. I have now taken the carbs apart 3 times and cleaned them to the nats ass. I saw someone talking about too lean of a mixture? I have my mixture screws turned out to between 3 and 3 1/4 on each one. Is this a symptom of a lean running bike?

 

Yes. The "choke" dumps extra fuel into the mix. If it won't run warm without it then you are lean.

Did you check your float heights? If the fuel level is ok you either have something plugged up or air leaking in after the carbs.

 

Greggers:

You're less than 130 miles away
Across 91, 84, 90, 495 and 3 ... It's NewEngland NASCAR Highway.

You'll be here in short of 2 Hours.
Come-over and I'll have you set yourself up until there's no tuning left to do.

 

ok....the thing will run like a top anywhere above 1500 RPM's, with the choke off, but once it falls under that, it sputters and dies.
I've turned the mixture screws down to 1 and still no difference, i've check the fuel screen and line...clear. The hose coming out of the airbox is clear as well as the hose from the intake boot to the petcock, i did run it without the tank on with just some gas in the bowls and the hose coming out of the intake boot would make a spit noise every so often, when i put my finger over it, the RPM's boost, i'm assuming this from better compression.....i'm clean out of ideas.

 

OK ... let's get tough with it.

Remove the Rubber Dunce-Caps off all four of the Intake Manifold Vacuum Pipes and SEAL them with a pinched-off wrap of Duct Tape.
Eliminate the possibility of air getting-in through them.

Remove the Air Cleaner and leave the Air Box OPEN.

Bring the Pilot Mix Screws Out to:
Not quite a whole 3-Turns.
Like ... 2 Hrs 50 min. (2-3/4 - Plus a little bit more. Splitting the difference between 2-3/4 -and- 3.00 -- erring on 3/4's not 3.

Propane torch.

Run it on a tune-up tank if it will go. Warm it up and see what happens coming off idle and moving to 2750 or so. If it stumbles and bucks trying to get some rev's going ... see what happens when Propane is introduced to the Intake Mixture ... into the Airbox Boots from inside the airbox.

If the Propane Gas supplimanted Intake Air Enrichment causes the engine to respond better coming-off Idle ... then, you'll know that the Pilot Jet's and the Top End Supply's ~~> Siphon Tube's (thin brass tubes extending down into the Fuel Bowls) along with the Metering Jets supplying fuel to the "Well" in the wall of the Fuel Bowl need to be checked for possible obstructions.

The Metering Jets in the bottom of the Fuel Bowl have no effect on the level of gas appearing in a clear hose level test. Despite the correct Fuel Level ... the WELL could very well be EMPTY.

Watch the level rise in the well when fuel is added to the bowl. The well level and fuel bowl level should equalize. But, the small volume of fuel in the well needs to be able to be drawn-up into the Top-Side through the narrow Brass Siphon Tube.

Explore the Metering Hole and the area above the Metering Hole at the bottom of the Siphon Tube with a Cleaning Tool.

One of the small probes in a set of Welders Tip Cleaning Tools fits that port with precision.

 

ok......i'll get to work and see what i can uncover.....thanks a bunch

 

ok, the propane helped but the idle still studdered. I took the bowls off the carbs and the holes in which the siphon tubes go into, in the bowls themselves, are not the cleanest. I held a pen light up to the opening in the bottom of the bowl and could only see a slight amount of light, in two of the bowls, through the top of the shaft in which the siphon tubes go down into, i ran out of time to clean them. Could this be my problem. Also, how do i make sure the siphon tubes are clean, i stuck a small probe up the brass tubes and they are clear, but i'm not sure if the space above the tubes are clean.......thank you

 

You got it!
You're there.
Bingo.

Generally, <~~ generally ... the Siphon Tube does not become fouled above the line of maximum fuel height. Good for you.
So, bend the probe slightly and clear-out what you can.

Snip some lengths of HEAT SHRINK and seal the Carb Cleaner's Red Tube to the Siphon Tube and then hook-up the can and blow it OUT!

The WELL metering ports can be Son's-a-bitches to de-clog sometimes.
Use a Red Tube as a both a probe and a lance.

Whittle the end of a Red Tube to a narrow point and begin. The plastic will work on getting the crap dislodged and won't hurt the passages.

You're just about there.
Nice perseverance.
I knew we'd get it.
I had a good feeling about how this was going!

 

i can't thank you enough, your a life saver...

 

well, i cleaned the siphons and metering ports and did a good cleaning on my carbs, for the fourth time now trying to fix my problem, put the bike back together, had it idle for about 5 minutes, the idle was falling slightly just leaving it in the same place, it was running a little rough, kinda coughed a few times, i took the choke off, blipped the throttle when i knew she was warmed and putt putt blah, it died. I hope somebody has another idea, i'm just about ready to forget the money i've put into the thing and crush it......