Motorcycle Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
I posted this in the repair section but thought I would post it here too. Need help finding an answer, Thanks:

I have a good one for you. I have been working on an 82 Maxim 550. Cleaned the carbs, new inlet needles in all carbs, replaced the petcock and shut off diaphram, new plugs fresh oil. Bike starts and runs great, idles great, until i test ride it and then it won't rev past 4500 RPM, it just hits a wall and stumbles. Tried choking it at this time and it doesn't help at all. Odd thing I noticed, if the blinker is on while at this 4500 rpm, it WILL rev each time the blinker bulb is going off, same thing when I tap the brake. Right as the brake light or blinker bulb goes off, like there is a spike in voltage it will rev better, if I blink the brake lever real fast it will rev all the way up. Must be electrical problem with it not reving. What can it be? It cranks and starts great which makes me think the battery etc is OK, the headlight is nice and bright.

Help, I'm not that great electrically and there has to be a logical explanation why when the bulbs a shutting off that the bike revs for an instant.

Thanks,
Joel
 

·
Registered
Joined
·
137 Posts
Could be the regulator/rectifier, or the TCI unit if it has one. Or It could be a bad battery or loose cable. Check your charging voltage with a meter, with the revs around 3000rpm. It should be around 14 volts. They'll start with battery voltage as low as 9 volts, but the electronics won't like it, so if the battery has a leaky cell, that could be it, especially if the battery is old.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #3
The volts idling and reved up stay above 14 volts so I think the regulator must be OK. I'm going to try to borrow an ignition box from the local cycle salvage yard tomorrow and eliminate that possibility. If they have one it is an easy plug and test run to see if that is maybe the problem.
 

·
Super Moderator
Joined
·
1,581 Posts
The Maxims and Secas from the early '80's had a pretty weak ignition system. Ended up changing both pulse coils, CDI box and coils on mine when it went funky on me. Got a "package deal" at the local salvage yard.
 

·
Registered
Joined
·
370 Posts
I posted this in the repair section but thought I would post it here too. Need help finding an answer, Thanks:

then it won't rev past 4500 RPM, it just hits a wall and stumbles. Odd thing I noticed, if the blinker is on while at this 4500 rpm, it WILL rev each time the blinker bulb is going off, same thing when I tap the brake. Right as the brake light or blinker bulb goes off, like there is a spike in voltage it will rev better, if I blink the brake lever real fast it will rev all the way up. Must be electrical problem with it not reving. What can it be?
You need to go through the entire electrical system and correct years of lack of maintenance. Clean all electrical contacts on the entire harness with contact cleaner and coat with dielectric grease. This includes grounds, bullet connectors, plugs, fuse box and switches (do those in a clear plastic bag so you don't lose small parts and springs). THEN you won't be chasing your tail when you try to troubleshoot. Cumulative high contact resistances on these old bikes can cause weird behavior and all sorts of damage including burnt stators and failed R/R's.
 
1 - 6 of 6 Posts
Top