1986 vfr 700 will not start, have gas , have spark, starter works and engine turns over

I have cleaned and checked all ground connections but no luck. I have tried spraying starter fluid into carbs but still no combustion. It started briefly one time when gas tank was off and disconnected, i poured a little gas in carbs in the evening to try starting again, no luck, then tried first thing in the morning and it cranked over until fuel ran out. Could this be a timing issue and how do you check timing? Could this be related to camshaft cam sensor? How do you check to see if it is good? Please help, thanks!

 

Timing won't have changed from the last time the bike ran, neither spark nor cams. You need to obtain a paper or electronic copy of the service manual--and READ it !-- to avoid damaging things and wasting time, will answer your questions.

Dija check all 4 plugs for spark ?? Did you find fuel in the carbs when you cracked open a drain screw ? Could be bad fuel pump or its relay........or a dozen other things. When did the bike last run ?

Don't use starting fluid as it can damage pistons, rings, cylinders !

 

Yes, checked all 4 plugs and do have spark. Yes, checked for fuel by "cracking" screws and fuel came out, so bowls are filled. Fuel pump was removed and shorter direct fuel line in place instead, (read on forums that this is ok with gravity feed, even on some race bikes) and fuel is moving through fuel filter, but fuel filter not filling up completely. (does it have to?)

 

Gravity feed works best only when tank is nearly full. Filter will normally look not completely filled, that's OK. You've done alot of fruitless cranking, so battery is due for a recharge.

When did bike last run ?? Might need carb cleaning.

 

Carbs have been cleaned and are working properly. Tank is 3/4 full. I have been charging battery on a trickle charger every time in goes low, because YES, you are correct, i have been cranking and cranking. It started once briefly last week in the morning at first crank, but not since then. I have gone through all major grounds i could see and sanded them and sprayed with electrical cleaner for solid contact. Thank you for your time thus far and please continue to brain storm as i have.

 

If you have spark then the carbs might be clogged, since you're not getting the correct fuel mixture. how long has it been since it last ran? When were the carbs cleaned and were all the jets and ports verified to be open to the correct diameter? is the fuel fresh or old. How much fuel can you drain out of each bowl? a few drops doesn't tell you anything--shut the petcock and collect the drainage from each in a tuna can and compare levels, etc. My money is on clogged carburetors.

 

The carbs were professionally taken apart and cleaned. I poured some fuel in the carbs as well, to get fuel in the chambers, even took out plugs and squirted fuel in. It should have at least made an attempt to start. Carb bowls are full and draining nicely.

 

Well, commence to jigglin--it sounds like you've got an answer for all the questions and are good to go in all aspects...so ride that thang!

 

I have checked and checked and tried to get it started. Could it be the REGULATOR / RECTIFIER ? How do i check to see if it not working? I just don't get why? Very frustrated with this and i appreciate everyone's time and brain storming.

 

Carbs were professionally cleaned, how long ago? If it ran briefly then everything is set in about the right spot. Nothing to do with rec/reg trying to start it

 

Did you check the gaps of the plugs? I would try a regular set of copper plugs in case you are using those fancy Iridium's that do not do nothing for your bike except costing more money and make it harder to start your bike. I think the plug gap number is in the owners manual, just get a wire gauge to verify. And yes it could be your stator or r/r. The shop manual shows you how to properly test the voltage at idle and something like 4000-5000 rps, I think its like 12.5v and 14.7v or something like that.

 

Carbs were cleaned about 6 weeks ago. I do not have a shop manual at this time so i don't know the spark plug gap, but that sounds like something to explore. The plugs are regular single contact plugs. Can someone check their manual for the gap clearance?

 

Well if you have spark and fuel how aboot compression?

 

I have not thought of that, that is a good lead. I will check compression, how many pounds should it be ? . . . and by th way is that your toe, or the lack of ? Wow.