Pegasus Overheat - A New Theory

[lanceq]

Friends - I have a new theory on why some QLink Pegasus' overheat. It's this:

The machines are never tested at full load with all the fluids on board. I am sure the factory tests engines and parts, but not a finished bike under full load. The machines are delivered directly to dealers through the distributor. The dealer preps them, starts them, and maybe drives them around. But a dealer never has time to test every bike for a prolonged time or under load.

Now here is the problem. When the dealer adds coolant, the system is not properly bled. There is an air pocket or low coolant. It's important to know–the Pegasus will run without coolant. Eventually, the low/no coolant Pegasus overheats for the new owner. The overheating is first seen at the temperature gauge, then in coolant boil-over, and finally as a head gasket problem.

I believe this is the primary reason for various Pegasus owners to have the overheating problem. If the head gasket has not blown, the solution is to drain the cooling system and properly refill it, making sure it is bled of air properly.

That's my thoughts today. What do you think? - Lance

["Big Guy"]

Nah... it's a casting problem with the head that they apparently have resolved and knew about it a long time ago. This has already been confirmed by several sources, though no one from the factory will admit liability due to the monetary losses they will suffer with a recall. I guess they figure that time will heal all claims and the complainers will cut their losses...


-Rich

[lanceq]

No, the casting theory is wrong. If it were a casting issue, the number of overheats would be substantially greater. The "several sources" argument is untrue. They comes from conjecture and anecdote, not engineering. - Lance

["Big Guy"]

If you say so, but this comes from a very reliable source and it's not a theory. The reason you don't hear about it more is because so many people are using them either with light loads or at low speeds, or they just don't complain here! I don't know any real person (not a board mole) that doesn't have this problem on the 06 and early 07 Pegs.


-Rich

[gymbeau]

The "several sources" argument is untrue. They comes from conjecture and anecdote, not engineering. - Lance

How does one prove an 'untruth' ?
Please prove that Richs statement is from conjecture and anecdote. I know of some of the
sources for his statement, and know them to be credible, and 'in the know'.

Did your theory cure your Pegasus? It certainly did not cure mine. If it did, would Qlink
be springing for a new engine for mine?

I don't pretend to know what is going on with mine, and will be the first to say that the 'blowing
coolant' seems to have a mind of its own; it happens sometimes, and sometime it don't.

Not jumping on you Lance (but I am defending Rich) I just feel that there has been too much
'conjecture and anecdote' on this subject already. Some facts would be nice, but Qlink ain't
talking.

Qlink is (very, very, slowly,) taking the necessary steps to address this problem. The question
is, is it too little, too late to save their reputation? Or just in time?

[thezapper]

FWIW, My B&M dealer (in Irving, TX) commented that he had several pegasus's 'fixed' by this; and he has his tech do this as a 'first step'.

Dunno if it is true or not.

When I was having problems, I basically filled, reburped, and otherwise flushed the cooling system. It seemed to help for 'awhile' (while riding hard for a few hundred KM); but now it's back; so I'm personally leaning towards the manufacturing head gasket theory still.... but again, maybe there are shades of gray and degree of being affected. My problems did not 'start' until 3500KM.

One of these days, I'll throw the Peg in a truck and leave it at the dealer too see if the warranty is real on this issue or not.....

TZ

[mkjeld76]

How many times do I have to post here, have been a member since last June. I have had my 07 since July and ride it hard. I commute 30 miles to work every day it's not raining. I have over 6600 km on it. I do all of my own maintenance I'm pretty sure my dealer didn't prep mine only paid $1999 out the door I prepped it myself. I had to wait a few weeks till he got 2 in thank god the 06 he had sold a week before I came looking. I bet many of these dealers hadn't prepped them well why should they. They believed all the hype that qlink and all these forums put out there.

["Big Guy"]

Dude, did you ever think that you may have gotten one of the good ones? The ones in question were manufactured from 05 to 06 and branded as 06 and early 07 models.

My source is very credible and a few people here know who he or she is, but I have promised not to divulge his or her identity... figure it out. There is no speculation or conjecture here.

You don't have to keep posting, just thank your lucky star you got one from a good casting!

How much would you like to bet that when Qlink replaces Gymbeau's motor the problem disappears forever? It has nothing to do with the cooling system or air in the lines for this particular persistent problem.


-Rich

[savage223]

Sorry I didn't see this sooner, but I don't spook around as often anymore; my opinion is already out there, and without substantial proof I'm going to stick to my guns. Mine is factual based on the physical examination of my ride; and some from feedback from members here and owners from other sites.

That being said, Lance has a point. It is a bit more tricky than simply adding coolant to the radiator- if you've completely drained the system. A bit trickier still is that- for the inexperienced rider- the reservoir / overflow tank is NOT the right place to fill to ensure proper coolant capacity. (Take the front shroud off to fill gain access to the radiator cap, and fill PROPERLY from there.)

Lance is right in that you must "surge" the system WHILE filling, and AFTER the thermostat has had enough temperature to open up. If anyone re-fills an empty- or low- system without following this procedure, I'd say that hands-down I'd NEVER guarantee it to be full.

The reason, as somewhat explained previously, is that there is a substantial difference between the height of the radiator, overflow tank, and engine circuit. This has the tendency to trap air pockets at different levels- even though logic would indicate that the radiator is the high point, and all bubbles should naturally work themselves out. (As the air "rises..") This is NOT the case for some reason- I'd guess the point would be between the radiator and pump inlet- or just following the thermostat.

It really doesn't matter- but do this, if you want to ENSURE the system is purged as good as you can get it. (And without special tools or attachments.)...

1. Pull the front shroud to gain access to the radiator. You'll have to disconnect two electrical lines to the running lights - it doesn't matter which way you put them back on later.

2. Fill the RESERVOIR tank to the proper level.

3. (ENGINE COOL!) Remove the radiator cap. Fill the cap until it is just below the highest hole in the neck (the overflow outlet.)

4. Start the scoot, and let it warm up until the temp gauge begins to move. BE SURE to keep adding coolant if the level goes down.

5. At this point, and up until the fan kicks on, make sure you perform 6-7.

6. "Punch" the accelerator up to about 3000-3500 or so RPM. Do it quick, then release the accelerator. Bubbles and surges of coolant will happen, so be ready for any overflow under the bike. Use a rag if you don't like to clean up after this, but there's no guarantee it won't run on to the ground.

7. Add coolant between each surge, as needed, to allow coolant to remain at an idle level of just below the overflow outlet.

8. Use you're head when you do this, because the system IS under pressure, and the coolant WILL be hot. Put the radiator cap on, quickly. Use a rag to be safe.

9. Shut the bike off.

10. Observe what happens to the level in the overflow tank. Sometimes, the level will go up. (Normal.) Sometimes it will drop, (also normal- in some cases.) What happens is that, as the system cools, a vacuum is created in the radiator. It SHOULD reclaim some coolant after running at NORMAL high temp, taking it from the reservoir to make up the difference. Then, once the scoot is warm again, chances are good that the reservoir level will go up again, as hot coolant is expanded and pushed into the tank. In any case, fill the reservoir to the proper level.

Now, from here- I would secure the connectors to the running lights in a fashion that will make certain they won't interfere with riding the scoot. Take it on a mile+ long drive, making sure it goes up to the point where the fan kicks on. Try as much as possible to give it good throttle at starts, wind it up to 45-50, and vary the speed.

All this "test ride" jostling- in addition to the throttle surging when filling- SHOULD get all of the air out of the system.

I've NEVER avoided a level in the reservoir tank anywhere NEAR the low line. In fact, I'd rather have some spew out on the hottest days, and run it at that level (higher than the suggested lines) than to risk having too little. The inconvenience of having to clean up some drips of coolant, or the muffler, is worth knowing you have an adequate amount in the system.

The key to this whole thing- in my opinion ALWAYS with the Pegasus- is to do the throttle surges when filling the system. Without it, I wouldn't feel comfortable at all. This is especially true if your temperature gauge starts doing the funky chicken for no apparent reason. The latter is an indication that an air bubble exists, and is passing over the temperature sender at the thermostat. I had that happen twice, and both times the total coolant volume had to be increased- in the end- to make it go away.

The idea that some systems- brand new- had air bubbles in them, and that heads were blown for this reason after purchase? COMPLETELY viable and COMPLETELY possible. With or without a dealer prep. We're all human and could miss something like this very easily; and it's not like QLink put out service bulletins or gave dealers a written and formal checklist to perform. If the latter is true, then it was never communicated to me, and I've never seen proof of a written procedure.

[savage223]

I came up with something else that could help ensure a full system, for riders that know they're sticking with their Pegasus until it dies a natural death thousands of Km later.

You could optionally install a T fitting into the system. I would do so just AFTER the thermostat housing (where the coolant hose is located above the valve cover.) Connect the stock hose to the top of the "T" (which will be the bottom eventually,) so that the coolant path runs straight as opposed to right angles. If that makes sense. Add a filling tube to the right angle portion (the stick that holds the T up when you write the letter,) and position it upwards towards the underside of the seat.

Edited: In essence, you'll have three hose clamps at the Tee fitting- two for connecting the original hose ends, one for the new filler hose. You'll need an additional clamp for your terminating fitting on the end, which will end up visible when you open your seat.

Drill or cut a hole large enough for your hose, and if possible add a grommet to the hole to prevent the hose from getting worn. (Split a small vacuum tube lengthwise and epoxy to the inside edge of the hole to make a cushion.) A correctly sized grommet will also work.

Pull your new filler hose through the protected hole you made in the seat, and add a terminal fitting and cap. (You might have to look around for these a little, but a shop with good inventory will carry them.) The fitting probably has barbs or ridges in it, that grab the inside of your new filler pipe / hose. The other side is threaded for a cap that has a gasket. (You'll see these types of fittings at hardware stores for garden hoses... but you want something made from brass and plastic that will be o.k. around 300 degrees or more.)

With THIS modification, whenever you change coolant, you simply open your filler cap, fill until full. Fill your radiator until full. Turn the bike on and run it until the bubbles move around. Let the bike cool enough to remove your NEW cap, and fill again if necessary.

This section of the coolant circuit in the Pegasus is an intermediate high spot- similar to the top of the bottom elbow in a sink drain trap. It is highly susceptible to air traps. So your new intermediate high spot will have a place to purge air / add coolant. You may or may not have to allow coolant to run out of this filler pipe as you're performing your filling routine, but the mess is fairly easy to clean up with some Simple Green. The benefit is in knowing for certain that you've got enough coolant in your system. The only downside is the mess, a half hours' worth of work, and $10 in supplies.

Hope it helps.