My overheating issue

[AZ Erik]

Well my Banshee overheats within 2 minutes of riding. I clocked the head at 330 degrees once. I tore it down tonight

This is a blown head gasket right?

The other side

It on the jugs when I popped it off

Some hole? I've never seen this before. I can't tell if it goes all the way through or not

The plugs (soaking wet)

My really odd colored water pump:

 

I have no idea why the pistons are BLACK, but the black won't come off and doesn't appear to be carbon. I didn't clean the head I just took the pics and it was that clean. The block got hot enough at one point to boil gas on it. I'm at a loss. The water pump appears to be working but when I rev it up it takes like 2 seconds after I left off for the water pressure to increase. It doesn't trickle out of the hose but it doesn't spray out either. Is there anywhere I should look for blockage? The front of the jusgs , and most of the jugs still have water in it even after pulling the drain plug and draining the entire system.

[BigRed350x]

Black pistons means you are rich or running some crappy gas/oil. Overheating is caused by a lean condition or rich in some cases. Check your jetting. A new top end is probably a good idea at this point as well. Get your cylinders bored/honed and put in a new top end. When it gets that hot you risk warping your cylinders. Get it bored to the next size over, put the new top end in right, get some good gas, good synthetic oil (use normal oil for breakin) and check your jetting. Do a plug chop man.

[AZ Erik]

Jets were 320's it was overheating, then put in 330's and it still was overheating. Castor was Maxima 927. Gas was Shell 91 octane from Shell on Fortuna in Yuma I ran this same gas and mix in another shee with a milled head and FMF's and it had no problems at all. The riding was done at Gordons Well. There are no nicks or anything in the cyl's. The motor still pulled just as stong on the last 2 minute ride I took. This is bone stock except for reeds and pipes.

 

Here is the stupid move I made before heading to Gordons only days before. I put in the pipe plugs in the silencers a couple days previous to swapping out the reeds. I forgot they were in there. Started the shee up. The only place exhaust was coming out of was the gap around the Pro Circuit silencers because I had not re silicon'd them after repacking them. After the shee had been running for about 30 to 45 seconds I tried to rev it up and it didn't want to. So I 'worked' it up to about mid throttle with the plugs still in. Then noticed the plugs. Pulled them and it revved out fine. Simple mistake but I think it cost me the head gasket. This shee has never been easy to start. I need to have the choke on full even if it had been ridden within a couple hours and is cold. Now it takes many kicks to start. I'll do a compression test on it but might be putting a cool head on first. I wanted this top end to last me this dune season, then a 400 would go on.

 

Now one thing I noticed was either hose I disconnect from the radiator has water coming out when I rev it up. I'll be checking the water pump tonight or tomorrow but it was still spinning and appered to be pumping water before I tore it all down. At one point in time while out on my 2 minute ride the shee did backfire. This happened twice, once on 2 seperate runs. There were parts of the head gasket in the coolant and the coolant was a very very dark green, trans fluid looks fine.

 

What are the odds that I blew a headgasket due to those exhaust pipe plugs, which pressurized the head and kept water from flowing correctly? Thus the overheating.. Which way does a shee really flow. Is it from the motor (out of the head) to the top of the radiator then down to the water pump or vise versa.

 

Here's the rest of the pictures if anyone can make sense of this.

http://azsvt.com/gallery/tear-down1

[2twin350s]

i will almost bet your waterpump is trashed.make sure you pull the clutch cover and check the white nylon gear for the pump.what happens is at high rpms,the green impeller slips on the shaft cuasing loss of coolant flow.i would just get a megaflow waterpump and seal and be sure the nylon drive gear is good.the pump went bad and you popped the head gasket.also make sure your coolant is not 100 percent antifreeze.that will cuase overheating also.at this piont,your top end needs to be rebuilt.spend the 300 bucks and get it done and have your head checked for warpage.your hard starting is most likely due to worn top end parts cuasing low compression. i would also say replace your reeds during the rebuild and have it ported and polished.this may satisfy your wanting a 400cc engine.it will be really fast with a new top end and port and polish job.

[AZ Erik]

I finished up working on my truck so i figured I'd continue into the tear down of the Banshee, I found the problem. I held the water pump while 'kicking' it over by hand. Knew I needed to continue pulling it appart at that point.

SO it looks like I need the billet pump, gear, bearing and seal. The pump was rubbing the clutch cover. I haven't knocked out the bearing yet, I'm hoping the clutch cover isn't busted where that bearing sits.

 

Anyone know where to get that bearing, gear and seal that's not the stealership? All my local shops nearly double the mark up on everything. I have like 2 other motors laying around but can't find the clutch side. If I can figure out the piston size I'll look into getting a set of coated pistons. I'll snag a pump off ebay today but can't find a part number for the gear, seal and bearing.

Edited March 11, 2006 by AZ Erik

[racer]

the impeller looked very loose in its housing in the very first picture of it, but to have it not spinning at all is fatal, obviously.

 

and somebody thought i was stupid for recommending a billet pump as cheap insurance. might have to link up these two threads.

 

Erik do you mind if i borrow your pics?

Edited March 11, 2006 by gimmeabeer

[AZ Erik]

Have at it. The pin 'burned' through the gear, from the looks of it the nylon warped, not sure when. Here is more carnage:

What you can't see here is the plastic of the bearing housing jammed in the balls. It looks to me like the impeller end just warped and started rubbing, possibly causing the shaft to warp causing the bearing seal to snap, causing the pieces to get hung up in the bearning, causing the pin to melt through the gear.

and where it was wearing.

So due to this water pump I've got:

Bearing: $13

Seal: $13

Gear:? (Still can't find it)

impeller: $63 (Ebay)

Gasket set: $32

Possibly a warped head: $30 to 300

Bore and hone:?

Piston kit: $140 to $250

 

One very quick way to check your water pump is to pull the water pump cover off and try to hold the impeller while kicking it over by hand. Had I done that in the first place this would not have happened. Oh well, live and learn this is why I bought a Banshee again.

Edited March 11, 2006 by AZ Erik

[racer]

i wouldnt stress about the warped head. to check you just need a check plate, any bike shop with boring facilities should have one, and will probably check it for free. if it is fucked, just mail it to someone to have ground into a high comp head. 2 birds one stone.

[AZ Erik]

That's the plan, might as well go bigger while I'm in there. I was thinking of going 30 over as well as this 'should' be the stock bore.

[racer]

good plan. now heres make some guys make some mistakes. have the jugs measured accurately by a machinist then order your pistons in a suitable size, but order them BEFORE you cut the jugs. once the pistons come in the crowns will have a measurement of the pistons exact size, down to the .0001. or at least wiseco's do. that way your cylinders are closer to the actual size of the piston. not just the +.030 that you ordered.

 

just a tip for a tighter motor.

[Lepew]

I have seen the impeller blades warp out just like your photo on my bike. They caused the outside of the impeller to rub the water pump cover plate. It didn't cause a failure but I replaced it with another stocker.

[pipebomb]

on ebay

 

Billet High Flow Water Pump Impellor Kit NEW

 

this guy did have the bearing in his "store" too last time I checked.

[AZ Erik]

Wow pipebomb that's a friggin deal. I bought it. Very very nice find I almost spent more than that on just the impeller.

 

I thought about the whole jug deal. I'm going to go ahead with a set of Namura pistons but need to yank the jugs so they can be measured. Might as well do some porting while I'm in there as well. A timing plate should be added to this as well huh.

[2twin350s]

az erik,well i nailed that one right on the head i have a complete side cover set up with all the fixins. if interested send me a pm.i also have a coolhead for sale.i have all the parts you need.i got a whole engine sittin here.i will be parting it out shortly on ebay.

[AZ Olie]

Hey AZ Erik, I was just checking out your post, sorry about the Dune trip... If you need any help PM me and I'll give you a call, I live in Wickenburg, AZ.

 

I'll be off this coming weekend 3/18 to 3/19/06...

 

AZ Olie