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ViragoTechForum.com General Help 1986 XV1100 significant loss of power (SOLVED)

#1:  1986 XV1100 significant loss of power (SOLVED) Author: ddg2sailor Post Posted: Sun Apr 18, 2010 4:26 pm

After some work... after the flood...

And after some work was running fine.

He also filled it up with gas at the local getty. So he is going to treat the gas to be safe. But I dont think its a fuel issue. Im more inclined to think that a pickup is either wet or just giving out.

He says it runs like its on a single cylnder but the plugs are ok.

Seems to me that if its really running on my cyclinder it would be a major miss but he says it idles ok.... But then... if the pressure was low... would runni9ng with the choke at least make it run enough better to at least show us where to look? :)

What ya think?

Sailor


Last edited by ddg2sailor on Mon Apr 19, 2010 10:25 pm; edited 1 time in total

#2:   Author: 48vintage Post Posted: Sun Apr 18, 2010 4:56 pm

Have you checked for vacuum leaks?

Gary

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#3:   Author: grazingazer Post Posted: Sun Apr 18, 2010 5:23 pm

a little brief but you mention a flood...if it was salt water the wiring's prolly fubar...make sure the vacuum line to the pressure sensor is connected

#4:   Author: ddg2sailor Post Posted: Sun Apr 18, 2010 6:37 pm

It idles fine and starts right up.... but it seems to me that the exhaust sounds muted..... not enough spark.....

coil im thinking.... cept where is it?

We took the cover off the pickups... but there doesnt seem to be any issues.... changed the old ignitor back in.. diddnt run at all....

coil? :)

Im not thinking its anything like a vavle.... and I think the wireing isnt so bad....

Sailor

#5:   Author: ddg2sailor Post Posted: Sun Apr 18, 2010 8:36 pm

I check all listed.... and a quick google shows that some people say the engine is fuel starved and other bought a new coil and it diddnt fix it.

Since all of this happened a couple of days after he last filled we are gotta start there and change the gas filter... which as far as we know is the original.... Time will tell.

thanks for your replies :)

Sailor

#6:   Author: grazingazer Post Posted: Sun Apr 18, 2010 8:52 pm

CLICK HERE FOR SPARK INFO

#7:   Author: ddg2sailor Post Posted: Sun Apr 18, 2010 10:24 pm

Im not so sure I understand all of that , The TCI is the ignitor?

My brother got so flustered that putting the battery case back in I think he broke a connection... no blinkers , no rpm.... and then the motor cut out..... No fuel pump?

He takes things too hard.... and sometimes does more damage then good.

Sailor

#8:   Author: grazingazer Post Posted: Sun Apr 18, 2010 10:38 pm

the TCI is the ignitor...here's how it works: the pick-ups generate an electrical pulse [when the flywheel magnets pass by them] which is fed to the TCI which reads the right time to interrupt the ground circuit and does so [essentially its an electronic set of points and crankshaft position sensor] when the ground circuit is interrupted the coil on that circuit fires the spark plug [that's the short version]

#9:  Re: 1986 XV1100 significant loss of power SOLVED!!!!! Author: ddg2sailor Post Posted: Mon Apr 19, 2010 10:19 pm

After reading here and on google... I got on track.

First we had to restore the bike to running.... My brother had wired the + end of the generic pump to the brake light... brownish wire.

I checked the fusable link... ok
Dvm on the tap for the pump.... .07 volts
Once again asked my brother had checked all the fuses.

Sig Fuze blown.... with the pump online I replaced with a slightly larger fuse.

Now we are back to the original problem.

We dumped the tank and used lp air to blow the fuel filter into an empty spring water bottle. Pretty dirty but not as bad as expected.

Still running the same... and thinking about what I read on here....

Motor off.... rear wire off.... oddly nuff still ran the same.
Rear wire back on and front wire off...... just spins and spins....

So the rear cylinder isnt firing.

Put a screwdriver into the wire... held it close to ground and the spark must have been 3/4 inch long. Took the plug out and put it into the wire and ground it and looked for a spark... no spark... odd as it seems (at least to me...) the core of the plug had to have broken.

I went out and got 2 new plugs....

First changed the bad one.... gapped at .028 , spat for a while as the cylinder burned off the gas.... then it started to run fine....

My brother took it out... filled it up and went for a test drive.... well he comes back with a big old grin and we pulled a few bug's outta his teeth and changed the other plug.... which showed considerable ware... and it was gapped at .025. So for better or worse both are gapped at .028 and the bike is running well and I bought my brother some extra fuses.

Thanks All

You were a big help.

Solved!

Sailor.

#10:   Author: Matthew Post Posted: Mon Apr 19, 2010 10:37 pm

not likley that it broke inside, gas fould plugs just don't work anymore, even if only 5mins old, unless you sand blast em clean.

#11:   Author: ddg2sailor Post Posted: Mon Apr 19, 2010 10:40 pm

Matthew wrote (View Post):
not likley that it broke inside, gas fould plugs just don't work anymore, even if only 5mins old, unless you sand blast em clean.


Dunno.... all I can say is that it diddnt make a spark and the new one cleaned out the left over gas in like 45 seconds.

I have both plugs Il check the ohms in the morning.

#12:   Author: Matthew Post Posted: Mon Apr 19, 2010 10:46 pm

Wouldn't bother, just have spare plugs around, if you get throttle happy when its cold, or choke happy, or flood it, you can easily foul the plugs and the only cure is to change em.

#13:   Author: ddg2sailor Post Posted: Tue Apr 20, 2010 12:46 am

Matthew wrote (View Post):
Wouldn't bother, just have spare plugs around, if you get throttle happy when its cold, or choke happy, or flood it, you can easily foul the plugs and the only cure is to change em.


This just dosent track. While my brother is hardly a biker virgin.... he dosent tend towards conditions that would gas foul out 2 plugs much less one.

Seems to me that its become even more important to see if the rear plug has indeed catastropicly failed.... for certainly any condition that would cause the plug to get gas foulded... did clear the moment we put in the new plug... Is it so odd that a plug can fail this way?

Sailor

#14:   Author: Matthew Post Posted: Tue Apr 20, 2010 1:49 am

Yea what do I know...........

#15:   Author: ddg2sailor Post Posted: Tue Apr 20, 2010 2:19 am

Matthew wrote (View Post): Yea what do I know...........


I never claimed your not an expert... I just never claimed that I am. At least Im willing to investigate the point before I decide.

#16:   Author: grazingazer Post Posted: Tue Apr 20, 2010 9:00 am

since the virago charging system is a weak point on the bike it is necessary to be aware of the state of battery charge as well as being entirely sure that all connections are bright and tite it doesn't take much to foul a plug especially on a 24 year old bike...i suggest that you check your secondary wire resistance as well as your coil resistance...open and clean the contacts of every switch and relay that has been subjected to saltwater and check the continuity of every wire on the bike...or just wait for electrical problems to occur

#17:   Author: ddg2sailor Post Posted: Tue Apr 20, 2010 1:56 pm

grazingazer wrote (View Post): since the virago charging system is a weak point on the bike it is necessary to be aware of the state of battery charge as well as being entirely sure that all connections are bright and tite it doesn't take much to foul a plug especially on a 24 year old bike...i suggest that you check your secondary wire resistance as well as your coil resistance...open and clean the contacts of every switch and relay that has been subjected to saltwater and check the continuity of every wire on the bike...or just wait for electrical problems to occur


Thats a very good Idea..... its about the only useful info in the book that came with the bike....

But So nice to hear from you :)

Sailor

P.S. My Brother has upgraded me to Junior Bike Tech... but no mechanical endorsement. I havent popped any heads or taken apart anything on the motor but he told me " Its nice to have someone who know's what he is doing" , I gave large credit to the folks on this forum... but it still felt good.

#18:   Author: grazingazer Post Posted: Tue Apr 20, 2010 2:11 pm

i submit that information not from the book but from over 45+ years of experience as a professional mechanic/technician coupled with the years that i have owned and operated my current ride a 1981 xv750 virago...since you don't acknowledge the title of the book to which you refer i can't comment on it's usefulness but i do feel that your submitted acknowledgements to this forum are heavy handed sir

#19:   Author: ddg2sailor Post Posted: Tue Apr 20, 2010 2:17 pm

grazingazer wrote (View Post):
i submit that information not from the book but from over 45+ years of experience as a professional mechanic/technician coupled with the years that i have owned and operated my current ride a 1981 xv750 virago...since you don't acknowledge the title of the book to which you refer i can't comment on it's usefulness but i do feel that your submitted acknowledgements to this forum are heavy handed sir


Heavy Handed? Certainly not intended to be so. I think this people on this forum were a lot of help.

This may not count for much but there is much going on in the background that is kinda tipping me over. You might say Im being pulled in 6 directions at one time. If this makes me seem other then polite , I regret this and apologize.

Sailor

It was the Original Yamaha Tech book....

#20:   Author: grazingazer Post Posted: Tue Apr 20, 2010 2:25 pm

on behalf of the forum members as a moderator on this forum i accept your apology...perhaps i was hasty in my assessment of your intentions

#21:   Author: ddg2sailor Post Posted: Tue Apr 20, 2010 2:30 pm

grazingazer wrote (View Post):
on behalf of the forum members as a moderator on this forum i accept your apology...perhaps i was hasty in my assessment of your intentions


I consider this forum to be an excellant resource. Up until just after the flood I diddnt know a thing about bikes..... but im a fair auto mechanic. But I know what I dont know and Il admit it. I did come here looking for help and the info on this place is top notch and the people great. I hope I diddnt totaly get off on the wrong foot.

Sailor

#22:   Author: grazingazer Post Posted: Tue Apr 20, 2010 2:43 pm

first impressions can often be wrong impressions we will be happy to supply you with any information that we can and we ask only that you familiarize yourself with the rules of the forum which are posted in the banners on this and the home page...you will also benefit by familiarizing yourself with the board navigation section on the left of this page...i'm posting a link to an online manual that should go a long way towards helping you in future endeavors vis-a-vis motorcycle repair:
CLICK HERE FOR REPAIR MANUAL

#23:   Author: ddg2sailor Post Posted: Fri Apr 23, 2010 12:10 am

Just a follow up....

My Brother says the bike is running well. I understand that they make platinum plugs for this bike... Might be worth looking into.

I told my brother that its well recomended to keep a spare set of plugs handy... just in case.

Thanks All

Sailor
ViragoTechForum.com General Help 1986 XV1100 significant loss of power (SOLVED)


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