help with 81 yamaha maxim

[lil red]

hey guys, i just finnished up my 81 yamaha fix up with a new battery today
and i cant get the bike to actually run, itl turn over and backfire now and then but it wont run for more than a sec.

i pulled and cleaned all 4 plugs(4 cylinder)
and tomorrow in going to drain all the gas out of it (carbs too) and put about a gallon or too of preimium in it, and hope it runs

any other sugestions on what it could be without taking apart all 4 carbs without a manual

worse comes to worse ill take it to johns cycle when work picks back up
the man is amazing, and eventually im going to have him tune it to run perfict on premium(if you cant afford to run premium in a motorcycle, you should buy a bicycle)

thanks guys

 

[aaron47]

getting spark,fuel? is it a 550?650?700? 1100?i have a eleven special,which is pretty much the same bike.i have a factory manual for mine, so any questions.also check out www.xs11.com its for the yamaha special and maxim.

 

[ati190]

I have a maxim 650 (XJ650H), 82 of course. It sounds to me you have some sort of carb problem. Maybe the mixture isn't correct. Premium unleaded really means squat. Octane is essentially an inhibitor. What that means is, the more octane the fuel contains, the slower the fuel burns. The manual calls for 87 unleaded, so you putting premium gas in it means you are wasting your money . It's not going to make a bit of difference in the bike running or not. I would take apart the carbs, and thoroughly clean them. The problem I encountered were the carb boots were dry rotted, causing the bike to not run.

ati190

 

[lil red]

you guys are the bomb, its a 650 btw

im going to check out that site and get all the specs on the carb setup, and i just like to run better gas because you get a bit better mileage and it seems to help out the bike, and the carbs are tuned to run super

if i were to take the carbs off, would i have to re sincronise the carbs?
if i do ill just suck it up and take it to a shop, i know allot on working on motors, and im in votec (both teachers in the 2 auto programs are enduro riders and street riders)

but i just dont want to take the chance of screwing up the bike

thanks again guys

 

[ati190]

yes, if you take apart the carbs, they need to be resync'd. You can buy the tool, or just make one yourself using plastic bottles, and some hose. There's a write up somewhere on the net, ninja250.org as to how to make one. I made my own cheap with stuff i had laying around. It was fairly easy. Instead of the 2 bottles (since you have four carbs you will need 4 bottles). Just look around!

ati190

 

[lil red]

i think i could borrow one from a friend, i just have no idea of how to do it

and that homemade one is awosome, thats really interesting

 

[built2bashranger]

hey guys, i just finnished up my 81 yamaha fix up with a new battery today
and i cant get the bike to actually run, itl turn over and backfire now and then but it wont run for more than a sec.

i pulled and cleaned all 4 plugs(4 cylinder)
and tomorrow in going to drain all the gas out of it (carbs too) and put about a gallon or too of preimium in it, and hope it runs

any other sugestions on what it could be without taking apart all 4 carbs without a manual

worse comes to worse ill take it to johns cycle when work picks back up
the man is amazing, and eventually im going to have him tune it to run perfict on premium(if you cant afford to run premium in a motorcycle, you should buy a bicycle)

thanks guys

check the timing yet?? 180 of maybe??? i would check that first put on new plugs and wires and see what happens. if it backfires when turning over the fuel is burning

marcus

 

[lil red]

i know for sure the timeing isnt off 180, i didnt even get close to valves or cams

i just replaced the shift return spring and the gasket for the cover

and a couple other little things, not engine related

 

[firefighter]

fresh gas, in tank and carb floats and maybe some Sea Foam. That stuf fworks on my older projects like that

 

[Jason]

fresh gas, in tank and carb floats and maybe some Sea Foam. That stuf fworks on my older projects like that

I just did an abused 550 Maxim like that a few months ago. Drain all gas. Add two bottles of straight seafoam. Put petcock on prime and loosen the drains on each carb, one at a time, until they are filled with the seafoam then close drain. Put petcock to ON position. Leave for 1 day. Come back, open drains on carbs to let out nastiness. Close drains. Add 1 gallon of gas, start bike. Work the throttle until the bike idles on its own.