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  Topic Review (Newest First)
05-20-2011 07:49 PM
F6Rider Thanks for the tip

05-17-2011 10:12 PM
Originally Posted by F6Rider View Post
Project reassembled!
Problem being encountered now...

Rear cylinder is back firing. I'm afraid I may have misaligned the gears in the top end. I'm VERY afraid that I've done this because (unless there's another way) I'll have to remove engine from frame again to fix.

yeah you should always rotate the engine clockwise 3 full rotations after everything is aligned and the cam ladder is tightened down tensioners in just to make sure the cams and crank 9 so the didn't skip a tooth.. and are still lined up.......... if you got rid of the useless airbox you could prolly take the valve cover off and get to it good luck...... On some of the triumphs ill put the cams 1 tooth off and by the time I tighten everything down and do the 3 rotations its lined up.
05-15-2011 01:28 PM
F6Rider Okay...
Project reassembled!
Problem being encountered now...

Rear cylinder is back firing. I'm afraid I may have misaligned the gears in the top end. I'm VERY afraid that I've done this because (unless there's another way) I'll have to remove engine from frame again to fix.

05-13-2011 04:36 AM
laorentou10 Pay no attention, I'm just a stupid spammer that shows up every day with a different ID and from a fake IP
05-09-2011 10:48 AM
F6Rider Oh, and as a follow-up. This bike burned/leaked NO oil until this MAJOR malfunction/change occurred. Therefore something has failed within the engine suddenly, i.e. Ring crack, gasket failure, etc.
05-09-2011 10:40 AM
F6Rider To use a adolescent quote from my kids' cellphone chatter...


Queezy, this is NOT a place for your "quart a month is acceptable" arguement. It is off topic, so drop it please. My issue with burning oil has to do with something going majorly wrong with my engine and NOT what is considered usual burn-by. So please take your arguement elsewhere and only post here if it is intended to assist.

05-09-2011 01:08 AM
qweesy Ok without getting into a pissing match.....

The oil lubricates the pistons and no matter how well the engine is broken in some oil will be left behind and get burned away.

When an engine fires one byproduct of combustion is water, and this water tends to get into the crankcase. Through an irony of mechanics, the amount of water that builds up in the oil is roughly equivalent to the amount of oil that is burned away. Normally the apparent level of oil stays fairly constant, but if you did a lot of high speed running and got the motor really hot you might see a large drop in the oil level all of a sudden. Part of this drop in oil level is water being boiled away and part is an actual increase in consumption of the oil.

Fundamentally, seeing some oil consumption is a good thing, and apparent oil consumption should increase with higher speed riding. Obviously, seeing a lot of oil consumption can be a bad thing. but anywhere from 1 oz to a quart will burn off.

there will be a number of factors.

1.) How was the bike broke in ( I never follow manufacturer way of break in, I warm up to temp before i take off ALWAYS...... and without keeping the motor at a set RPM level I break it in hard for the first 50 miles, change the oil run it hard to moderate for 500 miles change the oil run Dino oil for the next 3-5k miles then switch over to synthetic)

2.) How many miles are on the engine.

3.) What kind of oil you use.

4.) do you ride like grandpa or like you stole it.

5.) engine design etc. etc. ( Subaru's eat oil like mad due to flat 4 design)

6.) Rings, Valve guide wear, valve seals, PCV, also high compression engines will use more oil than a low compression engine.

What I have noticed is I do alot of highway miles over an hour long at a given rpm range of 7k-8k Vulcan and 9k-11k on the Daytona the bikes will eat more oil during this time than the running around town putt putt, but by no means is anything wrong with the engine, ask a black-hawk Heli mechanic he'll tell you if it dont burn/leak oil then it isn't safe to fly

but just to ask and see what "group" your in.

how do you break-in? per manufacturer or run it hard?

without looking at it if it burns oil just on start up then Id say its your valve guides/seals if its all the time then your piston rings are more than likely shot.
05-08-2011 09:56 PM
F6Rider CuriousGeorge, your advise seems sound and accurate, I spoke with my father today and told him that I used the "(turn the head upside down and pour mineral spirits in the intake and exhaust ports, if it runs out then the valves are fubar)" test and he said the same thing, "if it didn't run out, then don't touch the valves."

There is not even a HINT of oil in the air filters.

Dad says same thing, "likely just the gasket". So I'm reassembling the bike tomorrow.

Yes, money IS tight and I still need to put new rubber on it. As well as the fact that I'm riding my Valkyrie to Gatlinburg for the week of Memorial Day, I don't wanna spend any excess cash on this project right now.

I plan to follow your advice and purchase some Permatex CopperCoat. I had used some on my boat head gasket and didn't have ANY further problems with that. It was 30 years old and had over a million hours on it; and when i was done, it purred like a lazy old cat. lol

Cheers and thanks...

I'll be updating my progress throughout the reassembly. Gonna take my time and clean it up as I reassemble, so it'll likely take all week. (Damn job)
05-08-2011 07:54 PM
CuriousGeorge F6Rider, just reread your posts from earlier. IF there is no significant oil in the air cleaners, and IF the valves are okay, and IF the auto lash is Okay...then I'd still bet on a crisped head gasket. I'll go out on a limb here and bet more than one pair of tools has wrenched on your motor previously. Inattention to head torque readings can be problematic and lead to unexpected joy for no apparent reason. I'd slap a new gasket on, and, against the Kaw service manual advice, I'd use either the spray on Permatex CopperCoat or the Yamaha head sealant on both sides of the gasket an hour before reassembly...not on the cyl or head....because if in a previous life someone did not use anti-freeze in the motor, there could be some minor corrosion that eyeballs can't see on the mating surfaces.

I'll be checking back and wishing you luck.
05-08-2011 07:22 PM
CuriousGeorge Okay, we're off topic from what F6Rider was asking. But just for the H of it, I don't putt putt anywhere, anytime. I rarely shift 1-2 below 7500, consistently hit the on ramp in third at about 8K and when I'm pissin off an HD guy I'll rev to 9500 3rd and 4th. Still have 64K on my motor and zero/nada/squat oil use between 4000 mile changes. If ANY of my bikes burned a quart/month, I'd at least hone and re-ring if the cylinders miked to within .002 of factory and over bore if it was beyond. But, that's me. And the last time I asked a shop mechanic anything I was riding a f'ing moped and packing lunch to school in a paper bag. Try this on for size, my c5 'Vette has 8 cyclinders and about 80 times the Hp of the VN750, and it also doesn't burn a quart/month...never met a 'Vette owner that did burn oil unless the engine was fubar...so why would a 60Hp twin suck that much oil unless it was hurtin?

Now, back to F6Rider, another question comes to mind...you said it was smokin out the exhaust, found oil on the piston etc...did you notice if there was a large amount of oil in either or both of the air cleaners?? If you did, then it's a clear sign of excess blowby, and that's a ring problem without question whether there is cylinder scarring or not.

Also, even though you didn't see an "obvious" sign of gasket failure, it takes less than .005 inch seal loss in the VN750 to cause oil migration.

The big question is, how many times do you want to pull that motor from the frame, and how much can you spend right now? The problem is that you yanked the mill before taking a CR. That would tell a lot. Because if the CR was low, but the valves are solid (turn the head upside down and pour mineral spirits in the intake and exhaust ports, if it runs out then the valves are fubar) then it has to be the rings. Or the gasket. Or the stem seals. Point is, once the pumper is outta da frame, replace all that is within financial grasp. Or, Rinse. Lather Repeat. Personally, I hate the repeat option.
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