Need help getting my bike running properly

[bolohab]

Hey guys first post!

Backstory:

I bought a Vision as my first bike about 6 months ago. I have a little experience working on cars but nothing major. Little did I know I would be working on motorcycles soon :angel: . She had 12,500 miles and was in pretty good condition besides dripping gasoline from the bottom ( from the carbs probably ? ) but apart from that she ran solid. One of the first times out I forgot to turn the choke down after the engine warmed up. I rode around for about 30 minutes then she died. Ended up buying a haynes manual and taking the carbs out and cleaning them. I didn't replace any parts or gaskets just cleaned them. After that she ran, but not like before. She seemed to have lost some power and the engine " caved in " if I ever tried to give it full throttle or close to full. I then moved and have not had my bike for about 3 months. When I got her back about a month ago she fired up after a little hassle. I've recently put 500 miles on her. At first I was having trouble getting both cylinders to run and had the right side spark blug wire popping out while I was driving. I started waiting longer for the engine to warm up and haven't had that problem anymore. The starter then went bad so I ordered a rebuild kit of amazon and fixed it.

Present issues:

I never have any trouble starting the bike. The engine sounds very strong. I can now give it full throttle and it won't cave in. When the engine is warming up there is usually some white smoke coming out from one, sometimes both mufflers. It is not thick and will stop after bike is warmed up. Also the bike seems to overheat while sitting after I warm the engine up unless I ride immediately. I checked the compression and it was around 60 without adding oil and after I added oil it went up to 90. I am planning on cleaning the gas tank with por-15 , soldering all electrical connections and finally tackling the compression. Any ideas as to where I should start?


Any help, tips, or stories are welcome!

Thanks!

- Charles

[pinholenz]

Since the engine is running, I'd like to suggest that you put in some upper cylinder lubricant in to your petrol tank. It used to be called Redex - don't know what brands you have where you are. It helps clean gum from piston rings, valve stems and so on. I give mine a shot each tankful and the improvement over a 1000kms is noticeable. I no longer have any hint of smoke when I start. I reckon I had some  gummed up piston rings.

[Rikugun]

the engine " caved in "

I hate when that happens..  :(  :P

I'm usually a little skeptical of "top end rebuild in a can" oil treatments but on occasion they can help.  :D  I must say though, stuck rings might produce bluish smoke whereas white smoke is indicative of coolant in the combustion chamber i.e. cracked head or leaking head gasket. Since the smoking stops after it's warmed it's probably (hopefully) just condensation. You don't mention where you are geographically but does it happen all days or just when the dew point is conducive? Early morning starts smoke but later in the day OK?

Regarding compression... Were the values fairly equal in both cylinders dry and wet? Was the test performed on a warm engine and with the throttle opened fully while cranking? Also, remove the spark plug on the cylinder not being tested to help with cranking speed. Hopefully the compression is good. Due to price and availability, addressing low compression is not really practical in a "rebuilding" sense anyway.  :(  EDIT: oops, I forgot... tight or no valve clearance will lower compression. I'm nearly certain you have not checked the clearances, right?

Regarding overheating - what are the ambient temps you ride in? Does the fan work? Have you flushed the system and added new 50/50 coolant, and bled any air out?

[bolohab]

Thanks for the quick reply guys!

pinholenz: Thanks for the tip ill look into it.

Rikugun:

I'm in north carolina. There is white smoke at startup whether its warm or cold, but its almost always pretty humid; ill try and see if it smokes more or less depending on humidity. I forgot to mention shes not as fast as she should be. My 0-60 is around 9 seconds.

About the compression, I was only able to test the rear cylinder, I have fairly large hands and for the life of me could not screw the gauge into the front one. Have you had problems with the front cylinder? I did not warm up the engine, but I did have the throttle opened fully with both plugs out.

About the valves your right, I have not checked them. Do you recommend starting there to solve the low compression? 

And for the overheating, I haven't touched the coolant. Ill change it next. I've changed the oil twice and the drive train once with synthetic valvoline. Its usually around 60 F outside give or take, and the fan works as far as i remember. I have the bike at my parents house for now  >:( but ill be working on it later this week. Hopefully all will go well as given my current situation shell be my only ride for a couple of months  :o  8) .

Ill post some pictures up this weekend.

[Rikugun]

Normally I'd say go ahead and the check the valves but I'd rather see you get good compression tests done on both cylinders first as it's a good place to start in engine diagnostics. The results will dictate where to go next. Just as important as the numbers you get is how close the two cylinders are to each other. Remember a weak battery will cause slow cranking and possibly erroneous numbers.

When you say the engine overheats what does that mean? Does the needle go into the red or just high up on the scale? For whatever reason the fan won't come on until the needle is fairly high on the scale but if it goes into the red serious damage can occur. There is a fuse holder in the headlight bucket for the fan so make sure that is ok.

Something I didn't comment on was the statement that it ran noticeably worse after you cleaned the carbs. This draws my attention away from low compression as the culprit unless it changed suddenly after messing with the carbs. Is it possible you dropped something into the inlet track when the carbs were off? Assuming you didn't and it simply ran worse after having the carbs apart it's not unreasonable to assume poor performance has something to do with carbs.

Another comment not addressed was the seemingly bizarre habit of the front plug wire popping off while driving. Equally odd is the notion that a longer warm up period resolved this issue. Can you explain this further? Is the wire too short? Not routed properly? Is the front cylinder spark plug well drain hole clogged? You'll find it on the left side of the cylinder head. 

[bolohab]

I bought a new battery  right before I fixed the carbs and though the bike sat a bit it still holds charge.

As for the overheating, the needle gets dangerously close to the red zone and if I remember correctly goes into the red zone if I don't ride after the engine warms up. It probably is the fan then. Ive replaced all the fuses.

Im not sure what the inlet track is  ??? . I worked on the bike at my friends body shop so there was lots of dust in the air. I think I may have connected some of the hoses back together wrong. There are two hoses that are not connected to anything, ill take some pictures next time im at the bike. The carbs are junkyard parts, and just about every screw on the bike is stripped  >:( .

About the wire popping out. The first  approximately ten times i rode the bike after it had been sitting, I noticed that if I gave it to much throttle at once (+75%) I would risk shooting the right plug out. I would then be running on one cylinder and pull over and inspect the bike. I would find the right plug wire out and covered in engine oil.  I almost always had a hard time starting the bike after it had been running on one cylinder, my reasoning for warming up the bike longer was that I suspected I had flooded the engine. The wire is the right length. When you say the spark plug drain whole I think i know what your talking about, but im not sure. Is it just a small drill sized hole on the side of either cylinder? If so i have noticed some green coolant looking liquid coming from the right side hole.

[Tiger]

 :-\ You must have a working fan!!...are you aware that the fuse for the fan is in the headlight bucket ('82's) or in the wire loom holder behind the headlight bucket ('83's)??

I run a large box fan when working on Vision's (and all bikes)...this helps keep the temps down to a reasonable level in most cases... ;)

Each cylinder has a wee drain hole coming from each spark plug...run some compressed air through them and around the spark plugs to clean them out ;)

                            8) ....... TIGER .......  8)

[Rikugun]

I can't say I like what I'm hearing.  :(   I'd suggest not spending a lot of money on this bike until you at least get some accurate compression readings on a hot engine. Just to clarify, in your last paragraph you said "I would risk shooting the right plug out" and later "I would find the right plug wire out and covered in engine oil"  Which is it - the spark plug or spark plug wire?

Coolant leaking anywhere around the cylinder or head is never good. That combined with the white smoke, oily front plug wire "blowing off", low compression and reduced power may indicate spell significant issues. When you changed the oil did it come out like a frothy tan milkshake? Do you see oil in the oil level sightglass or froth? Since you've accumulated some miles, I'd drain the oil again and check for signs of coolant contamination. Have you been tracking the coolant level in the overflow tank? If it's been steadily depleting that would be another bad sign.

I've done remote diagnosis long enough to know there is often a disconnect between what one reports and what is really happening but there are some significant red flags here. Often times these types of things end up with "oops, never mind! A vacuum line was disconnected.  :-[ It's all better now...."  ;D There may be simple explanations for these things but taken at face value I'm a little concerned.  Post some pics when you can of the coolant leak and whatever else you think noteworthy.

[bolohab]

Tiger:

I did not know about that fuse I replaced main ones under the seat; i'll check it out as well as run some compressed air through the holes.  :)

Rikugun:

It was the spark plug wire.

I remember inspecting the oil and not finding anything unusual though the first time it was pretty dark. The oil looks ok through the froth glass. I check the coolant periodically, but I haven't payed attention to exactly how full it is  :-[ .

I appreciate the help boys, i'll post some pics on monday.

[bolohab]

Hey guys had a hell of a week, barely got to start fixing my tank. I managed to get the petcock off ( screws were stripped bare ) and what came out was impressive. Lots of pebble sized rusted metal pieces , along with brown gasoline. 

Here are the pics of my bike http://bolohab.imgur.com/all/ , ill post more along with an update of the compression test in hopefully a week if all goes as planned.

Edit: dont know why one image ended up on the post.. find all pics at http://bolohab.imgur.com/all/

[Rick G]

HI Bo! Are you in Canada ? I see a bottle of Labatts blue.  It looks like your bike spent quite a few winters out side. I received  a set of carbs from Canada. They were  terrible. They were so corroded, I had to glass bead them to make them presentable . I have a set of front cyl head pipes . if your interested.

[bolohab]

Hey Rick! I used to live in Canada, im in North Carolina now. Good call on the bike, I bought it from somebody who had just driven it down from New York. Labatts is my favorite beer  ;D . I might take you up on the front cyl pipes. I'm planning on retouching all the pipes and exterior once i get the bike running right. I have zero experience with this type of thing but I figure a restore manual and some online forums will do the trick :) .

[bolohab]

Hey guys I'm back sorry to leave you hanging especially after the great responses. I rebuilt the tank and did a compression test. The rear cylinder took about 3 seconds to get up to 120 psi. The front cylinder seemed a bit stronger, building up to 125 psi faster. Then I added some oil to the cylinders. The compression improved to 150 on rear and 155 on the front. According to the haynes manual, its probably worn stuck piston rings and or cylinders. Time to inspect them. Should be fun :) . What do you guys think? The procedures seem complicated so all advice welcome, this will be my biggest job jet.