Need help, have tried a lot of things and don’t know how to continue.

Hello,

I have a 1982 seca 750 that I have been working for a few months now, doing a from frame restoration and don’t know how to continue.

To start: I originally bought the bike quite few years ago and was a daily rider for a year before being out in a garage for storage. 2 years later, go to get the bike running, was able to get it started but obviously needed carb work. And the battery needs to be replaced, still holds a decent charge, but drains quickly when you crank the motor.

Went through the carbs twice before I sent them out to be completely rebuilt, cleaned and set back to factory settings. When the carbs got back, I inspected everything and they were brand new inside and out and set to factory settings.

Installed the new carbs and the got the bike running somewhat decently but seemed like the carbs were out of synch a little. Next day, I went to go synch the carbs and couldn’t get the bike to start.

The spark plugs are new and I’m getting nice bright blue spark on all 4 cylinders. I’m getting great compression. I’m getting fuel, getting spark yet the bike just cranks. It also doesn’t start with starting fluid, sometimes it will backfire here and there. I’m not really sure how to proceed or what to check next. I have tried a few things and can’t seem to get Any change in results. Any help is appreciated!

 

Try a car battery and jump leads. Put a multimeter set to volts DC across the your bike battery terminals and press the starter button. If it drops below 10 volts your TCI transistors won't work so you will have no spark. When was the last time the valve clearances were checked? Those must be done before fitting gauges to balance the carbs to the engine.

 

Okay, tomorrow when I get out into the shop. I will put a meter on it see what it reads.

As for valve clearance I forgot to mention it was done about 2.5 years ago. About 3k miles put on after having them adjusted

 

Valves should be fine if only 3K done.

 

wouldnt hurt to check the shims anyways. probally not your issue but if any were on the tight side the last check it would be good to chek them.
did you write down your last set of numbers?

 

A battery that will charge, but drains quickly, is no longer a useful battery.
If the battery voltage drops to below 10 volts under a starting load, then the TCI won't be able to deliver a good spark under compression (checking for spark with the plugs out does not guarantee that they will spark under compression) and the bike won't fire.

 

+1^
What is the fuel tank looking like inside? I am hoping that is is good clean fuel getting to those nice newly cleaned carbs? I would just make sure that you have not contaminated the clean carbs with some bad fuel or bits from a rusty tank.

A little starter fluid in the air box would also give a little help. Pls be careful with that option if you chose to use starting fluid.

If you were running at first and then with a little fuel flow and sitting overnight, it will not start. I hope the fuel was good.

Draining a carb bowl using the screw on the bottom will also let you know if the petcock is flowing fuel to the carbs and they all have fuel in them.

Have you test the petcock to see if is working correctly. Turn to prime it it has that setting and make sure the fuel is running. When in the "on' and "res" setting, see if it will flow with or without vacuum.

 

Have you tried new plugs?

 

Have you found the fix to this yet. Im basically in the same boat. Check voltage to your coils. You need 12v to both coils for proper spark.

 

OP hasn’t been seen since Sept 1, 2021