Coolant leak - crankcase breather housing?

[windrider1983]

I have an 83 Venture(stock, not a Royale), and I have a small coolant leak. It has been very minor and originally only would be noticeable over the winter - I would keep an oil pan under the bike with a couple of paper towels and they would be damp by spring. Last summer it started to leave a drop or two overnight - that is when I started looking. BTW - I had rebuilt the water pump and replaced all the hoses a couple of years ago, so it is not the water pump or related O-rings or fittings. Over this past winter, it was worse – I lost what was in the overflow reservoir plus a little more. It appears to be coming from the front side of the crankcase breather box (I assume that is what that cigar-shaped assembly that sits between the cylinders is). Over a period of several days, the small hollow depression on the front side of the block, visible from the left side, will slowly accumulate green antifreeze (only when the bike is sitting on the big stand. When leaning on the kickstand, it runs down the left side, one drop at a time). I have checked all the lines coming out the top of that box and none have any residue or liquid at the fittings or clamps. The only conclusion I have been able to come to is one of the two gaskets leaks when it cools off. If it leaks when it's hot, it is so slow that it is burning off before you can see it.

Does anyone have any experience with this? Can the bolts be retorqued? If so, what is the correct torque (haven't been able to find it in the manual). What would be involved in replacing the gaskets? Can it even be done without removing the carbs, or more? Besides the couple of hose fittings, there is a banjo fitting with two chrome tubes running to the front and back cylinder housings - I assume those are coolant lines, but not sure - is there a write-up on this site that explains what each of these lines are for? I just like to understand what I'm looking at.

I did put a small socket on the bolts on the left side to see if there was any play in them, without putting too much effort into it – I fear snapping one of them off and having a real mess – but they wouldn’t budge. Since it seems to be worse when it gets cold, I even tried setting a ziplock bag of ice on the top of the assembly and after half an hour or so later, tried to tighten the bolts on the left side again. The bolt closest to the outside edge did budge just a tiny bit, but the two in the middle still did not move with the pressure I was using.

The first picture shows the well about half full of coolant, and the second shows a bit of coolant just under that bolt housing to the left of the well.

Thoughts?

[Prairiehammer]

The "Twinkie" (that's the breather/oil distribution junction/coolant cover) contains two gaskets; one between the two sections of the Twinkie and one at the base where it mates with the crankcase. The Twinkie contains pressurized oil feeding the heads (the chrome lines with banjo unions), coolant and a crankcase breather passage.

The gaskets are more akin to O-rings in composition and cross-section. The O-ring style gaskets become flattened and hardened (less resilient) with time and heat. Tightening the six mounting cap screws does not usually result in reducing the leak, because the housing bottoms out on the crankcase before the shrunken gasket is compressed.

Because of the construction and purpose of the Twinkie, it is not uncommon for coolant to enter the engine oil or engine oil to mix with coolant when the gaskets fail. Check your coolant reservoir for milky tan oil scum and your engine oil level (may rise).

It is doubtful that the gaskets can be replaced with the carbs in place (replace BOTH gaskets while the Twinkie is out). It would also be easier to access the Twinkie for removal if the intake boots are removed from the heads, but that may require replacement of the intake boot gaskets (also O-ring style gaskets).

[Patch]

Really Mr. Campbell? Could you be a little clearer? Maybe just stick to the facts, and just the facts?

Please.

Another amazing gift of experience Sir!

[uhfradarwill]

Whenever Mr. Hammer fesses up some knowledge, I'm in awe all over again.

Could you, Mr. Hammer, please upload your entire brain contents, concerning the Venture, and post it please?

Will

[Prairiehammer]

Could you, Mr. Hammer, please upload your entire brain contents, concerning the Venture, and post it please?

Will

 

Sure! Perhaps it does not contain my ENTIRE Venture brain content, but it IS all the Venture Stuff on my computer.

 

Go here:

https://drive.google.com/open?id=1fbU3AAk-9pJ74x-_Mk1NWUjC-OxPqW91

[uhfradarwill]

Sure! Perhaps it does not contain my ENTIRE Venture brain content, but it IS all the Venture Stuff on my computer.

 

Go here:

https://drive.google.com/open?id=1fbU3AAk-9pJ74x-_Mk1NWUjC-OxPqW91

 

That is quite the link.

Thanks very much!!!!!!!!

[campfire12]

That is quite the link.

Thanks very much!!!!!!!!

 

This site is amazing, Thanks to everyone!!

[windrider1983]

The "Twinkie" (that's the breather/oil distribution junction/coolant cover) contains two gaskets; one between the two sections of the Twinkie and one at the base where it mates with the crankcase. The Twinkie contains pressurized oil feeding the heads (the chrome lines with banjo unions), coolant and a crankcase breather passage.

The gaskets are more akin to O-rings in composition and cross-section. The O-ring style gaskets become flattened and hardened (less resilient) with time and heat. Tightening the six mounting cap screws does not usually result in reducing the leak, because the housing bottoms out on the crankcase before the shrunken gasket is compressed.

Because of the construction and purpose of the Twinkie, it is not uncommon for coolant to enter the engine oil or engine oil to mix with coolant when the gaskets fail. Check your coolant reservoir for milky tan oil scum and your engine oil level (may rise).

It is doubtful that the gaskets can be replaced with the carbs in place (replace BOTH gaskets while the Twinkie is out). It would also be easier to access the Twinkie for removal if the intake boots are removed from the heads, but that may require replacement of the intake boot gaskets (also O-ring style gaskets).

https://www.venturerider.org/forum/attachment.php?attachmentid=116970https://www.venturerider.org/forum/attachment.php?attachmentid=116971https://www.venturerider.org/forum/attachment.php?attachmentid=116972https://www.venturerider.org/forum/attachment.php?attachmentid=116973https://www.venturerider.org/forum/attachment.php?attachmentid=116974https://www.venturerider.org/forum/attachment.php?attachmentid=116975https://www.venturerider.org/forum/attachment.php?attachmentid=116976https://www.venturerider.org/forum/attachment.php?attachmentid=116977

 

Thanks for the info - that is exactly what I needed to know. And while the coolant does not appear to be contaminated, the oil most certainly has to be - the level is completely above the view window - which it was not when I put it up for the winter. So I have drained the coolant (so it doesn't leak anymore into the lube system), drained the oil, and put a piece of tape over the ignition.

I haven't planned when I will start the project yet - is there any harm in letting it sit for a while in the present condition?

Once the gaskets are replaced, should the engine be flushed to remove any residual coolant from the lubrication system? Sacrifice 4 quarts of oil and a filter - run it for a few minutes and then drain it all out?

I am thinking it may be an opportunity to rebuild the carbs as well, but have not looked at the cost of the rebuild kits yet, or everything that is involved with that. It currently runs pretty well, so probably not absolutely necessary, but with 85K they are probably due.

I have decided to purchase Big Auggie's 89 Royale so I can still get some riding in this season (plus it is a good upgrade from the 83), and I may have a buddy interested in the 83 once it is running again.

Appreciate all the info provided so far (and I am impressed by the Google Drive link, btw).

Mark.

[Patch]

If there is a chance that the coolant circulated then yes a flush is a good idea and you can use seafoam for the flush as well! You don't need expensive oil for the flush. But you should run it for say a half hour or an hour short ride, change the filter just the one time or both times budget permitting...

 

Either way don't cheap out on the filter

Patch

[windrider1983]

I started working on the twinkie today - got the carbs out, removed and cleaned up the twinkie, and now have a few questions.

1. The Crankcase breather tube is bad and needs replaced. Cannot find a diagram with that part on it. It appears to be a formed hose but not sure.

2. The tube coming out of the crankcase housing that feeds the pressurized oil fitting has an o-ring on it. It looks OK, but would make sense to replace it if I knew what size it was or the part #.

3. When I reassemble the twinkie with the new gaskets, is it appropriate to coat them lightly with a gasket sealer, or best to leave them as is?

Thanks for any info or opinions.

[windrider1983]

Of course, minutes after I posted the 3 questions, I stumbled onto the Air Filter parts diagram and found the breather tube part[TABLE=width: 64]

[TR]

[TD=class: xl66, width: 64](90445-11699-00)[/TD]

[/TR]

[/TABLE]

[Patch]

I started working on the twinkie today - got the carbs out, removed and cleaned up the twinkie, and now have a few questions.

1. The Crankcase breather tube is bad and needs replaced. Cannot find a diagram with that part on it. It appears to be a formed hose but not sure.

2. The tube coming out of the crankcase housing that feeds the pressurized oil fitting has an o-ring on it. It looks OK, but would make sense to replace it if I knew what size it was or the part #.

3. When I reassemble the twinkie with the new gaskets, is it appropriate to coat them lightly with a gasket sealer, or best to leave them as is?

Thanks for any info or opinions.

 

 

Sealer is not required other than perhaps a dab to hold the gaskets in place.

I usually place a thin layer around o-rings of silicone grease tho it is not called for. The sizing should be a match to the original in all cases or you can crack the cast housing.

[Prairiehammer]

Of course, minutes after I posted the 3 questions, I stumbled onto the Air Filter parts diagram and found the breather tube part[TABLE=width: 64]

[TR]

[TD=class: xl66, width: 64](90445-11699-00)[/TD]

[/TR]

[/TABLE]

 

If I understand correctly, you are looking for the hose that goes from a T fitting just above the twinkie to the larger nipple on the bottom of the air cleaner?

That breather hose is part number 47G-11166-00.

Apparently no longer available from Yamaha, although there are several NOS on eBay.

 

https://www.ebay.com/itm/84-93-Yamaha-Venture-Breather-1-Pipe-47G-11166-00-00-NOS/231520523300?epid=1811796370&hash=item35e7b2d424:g:JewAAOSw-7RVGxjQ

 

 

You said that the hose you needed was part number 90445-11699-00, however.

That small diameter hose originally ran from the smaller nipple on the bottom of the air cleaner to an inline filter and then to atmosphere. This arrangement for the air cleaner oil drain was only on the 1983 and was subsequently scrapped on later models and in fact there is a Tech Bulletin outlining a modification to be made, that would eliminate the drain filter and route the hose to a T fitting on the twinkie.

M84-017 Air Box Oil Leakage M84-017.pdf

Edited January 26, 2020 by Prairiehammer

[Patch]

Reminds me of an old Canadian expression: HE SHOOTS _ HE SCORES:canada:AND THAT IS WHY THEY CALL HIM THE HAMMER

Prairiehammer

 

Its worth remembering that crankcase vapor is explosive.

 

 

[windrider1983]

Thanks for all the info - it is as Prairehammer indicated - the update to the breather box and drain tube was never done on my 83. I have ordered the parts needed - the updated breather hose, the t-fitting, some clips. I will re-use the small drain line as indicated in the bulletin - it is still pretty flexible, even after 37 years. And I will seal the boots, as stated in the bulletin.

After that - take a look at the carbs.

Thanks again!

[Patch]

Easy to check compression with the carbs off.

[windrider1983]

Surprisingly, I found no problems with the carb boots and the diaphrams were all good, so we decided to put it back together today. We reinstalled the distribution module with the new gaskets, and then reinstalled the carb assembly. After attaching the throttle cables, we noticed that the throttle was no longer returning freely - sticks especially after twisting it wide open. We cannot see where we have anything connected wrong. Is it possible we stretched one of the cables and it needs adjusted? Or other likely suspects?

I have not found an adjustment procedure in the manual, but still looking.

Addendum before anyone had a chance to respond - on a hunch we unclamped the carbs, pulled them loose, and reseated them without clamping - and the sticking throttle was gone. Seemed like something was applying a small warp to the linkage and causing it to hang up a bit. After reclamping the boots one at at time and checking the throttle in between each, we got it to an acceptable point.

Airbox is back on, though I am missing a spring clamp to complete the install of the service bulletin noted above (bought the ones noted in the bulletin, but did not realize one of the originals was missing) - will try to find one tomorrow.

Edited February 16, 2020 by windrider1983
new info

[luvmy40]

I'd double check the cable routing from the sheild seat to the cam/pulley. IIRC, you can get one or both cables on the wrong side of an axle and it looks fine but doesn't work very well. There are some plastic bits on the axial links that look like the cable should be run over them but they don't actually ever contact the cables.

[jfman]

Do the carbs have to be off to be able to remove this piece from the bike?

[windrider1983]

Do the carbs have to be off to be able to remove this piece from the bike?

I asked that same question early in this thread, and was told yes. Having removed it with the carbs off, I can't say for certain that it couldn't be done with them on, but it would be difficult. You would have to disconnect the steel oil lines (with the banjo fittings) from the cylinder heads, and be able to crack loose the 6 bolts holding the asembly to the crankcase. Those came loose fairly easily with a socket wrench working from above (with plenty of room for applying leverage), but not sure you could get a good byte on them coming in from the side. Another tricky part would be setting the unit back in place and keeping the new gaskets properly aligned. If that is not right, then you are back to square one.

Having done it the 'easy' way (pulling the box and carbs), I might try to get it loose first and see how far I could get, but be prepared to fall back to the original procedure.

[windrider1983]

Final (I hope) conclusion to this thread - everything is back together, it started relatively easily and runs great. Flushed both the oil and coolant systems with new fluids and oil filter, then drained both and filled with new again (and another new filter). Shortly thereafter, we had a break in the Ohio weather and I took it out for the first time in nearly a year and it felt good. The rear brake needs adjusted badly (or it has air in it) so that needs some attention, but NO LEAKS anywhere that I can see.

Thanks to everyone who provided assistance and advice.

[jfman]

You guyz are making me spend too much money.

 

Since both my Ventures are apart for carb/valves, I just ordered these gaskets to be safe.

 

And this is how a 350$ Venture becomes a 1000$ Venture

[jfman]

I would like to add to this that if you take the time to take this whole thing apart, theres an oïl feed tube that goes from the Bottom end to this housing. That tube has two orings and it might be a good a idea to repalce them as well and it will take you 2 minutes.

 

Also after doing this job on two bikes I do not think it can be done with the carbs on.

 

Event with the carbs and the intake boots off, I had to pull the nut off the tensionner to get my some extra room to pull this item.

 

On one of the two bikes, the aluminum mating surface was corroded beyond the seal and it was just a mater of time before the collant would contaminate the oïl. I sanded the surface with 800 grit to remove the corrosion and I Added Yamabond before installing the piece.

 

I think this job needs to be Added to a must do while the carbs are off if you care for your bike.