The World Famous Bull Sessions

Show Us What You Are You Building? => Resurrections => Topic started by: sdsnocop on January 07, 2021, 12:15:12 am

Title: New project 1980 SRX
Post by: sdsnocop on January 07, 2021, 12:15:12 am
Brought home my next vintage project. 1980 Yamaha SRX. Minus - motor is locked up, hood is cracked and faded, seat is gone, tank filler neck is broke. Positive - Mostly complete except missing air box, Aaen pipes, Comet Clutch, and biggest plus it only cost me the gas for a 140 mile round trip.
Title: Re: New project 1980 SRX
Post by: opsled on January 07, 2021, 02:08:18 am
Tunnel and belly pan condition is the biggest thing on an 80. That one looks good. Engine isn't a big deal. Everything can be had. Fuel tank can be repaired. Mike Vollmer welds in an entire new updated assembly in for $70. Looks exactly like original and works perfect. Seats can be had too. There is a guy on facebook reproducing exact front bumpers out of stainless steel that look as good or better than original. Looks like a good project.

opsled
Title: Re: New project 1980 SRX
Post by: sdsnocop on January 07, 2021, 04:18:36 am
Tunnel and belly pan condition is the biggest thing on an 80. That one looks good. Engine isn't a big deal. Everything can be had. Fuel tank can be repaired. Mike Vollmer welds in an entire new updated assembly in for $70. Looks exactly like original and works perfect. Seats can be had too. There is a guy on facebook reproducing exact front bumpers out of stainless steel that look as good or better than original. Looks like a good project.

opsled

Several dents and dings in the bottom of the belly pan but not too serious. I notice the belly pan material is much thinner on the SRX compared to the Exciter. The right foot board is bent down some. Noticed some of the gold anodizing is starting to come off on the rear of the tunnel on one side.
Title: Re: New project 1980 SRX
Post by: sdsnocop on January 07, 2021, 04:22:48 am
Started motor disassembly. Removed 1 cylinder, both cylinder and piston looked good. I have the other cylinder soaking in penetrating lube. Looks like the crank is toast. Rusted and stuck tight. Both the Comet clutch and stock secondary clutch looked good just needs a good cleaning. Both carbs are dirty but the butterflies are free.
Title: Re: New project 1980 SRX
Post by: DJS800 on January 07, 2021, 05:43:43 pm
It sounds like you have a good sled to start with, as long as the crank is not spun I would have it totally rebuilt, I have had a couple done by a guy in Minnesota, I cant think of his name right off the top of my head??? If you need it I can look it up in my paperwork.. 
Title: Re: New project 1980 SRX
Post by: 73 RATX on January 07, 2021, 09:19:41 pm
Bill Bune?
Title: Re: New project 1980 SRX
Post by: sdsnocop on January 08, 2021, 03:23:04 am
Split the case tonight. Looks pretty ugly. I though I would get by saving the top end but the piston was very stuck in the bore of one cylinder. The skirt of the cylinder cracked and broke before I got the piston out. It looks like this is a mix year motor someone built. Case and crank from a 80 with fully intact auto oiler system, 8F cylinders from a 77 SRX and 8A heads off a 76 SRX.
Title: Re: New project 1980 SRX
Post by: Earl on January 08, 2021, 01:15:35 pm
  Wow !!!!!!!!!
Title: Re: New project 1980 SRX
Post by: yamakid on January 08, 2021, 01:42:10 pm
Were both cylinders 8F2??
Title: Re: New project 1980 SRX
Post by: sdsnocop on January 08, 2021, 04:52:09 pm
Yes both cylinders are 8F200 and both cylinder heads are 8A700. Pistons are 09-818 Parts Unlimited pistons which look new with almost no wear.
Title: Re: New project 1980 SRX
Post by: yamakid on January 08, 2021, 06:47:43 pm
Yes both cylinders are 8F200 and both cylinder heads are 8A700. Pistons are 09-818 Parts Unlimited pistons which look new with almost no wear.

I'd say you came out ahead on this deal!!! Clean/sell those cylinders and heads and you'll have most of the budget for the remainder of the build covered. But is your build so do as you please.
Title: Re: New project 1980 SRX
Post by: sdsnocop on January 08, 2021, 08:18:43 pm
One cylinder is good. The other has a rusty bore which could be cleaned up and replated. I do not know if a shop can repair the broken cylinder skirt. It looks like the aluminum casting portion of the skirt is missing. 
Title: Re: New project 1980 SRX
Post by: jschaffer on January 09, 2021, 05:01:45 am
They come with a chrome cylinder.  Looks like they have been sleeved with a cast iron sleeve.  You could get them re-sleeved.
Title: Re: New project 1980 SRX
Post by: Skier76 on January 09, 2021, 02:48:43 pm
Cool project! I'll be following this one.
Title: Re: New project 1980 SRX
Post by: opsled on January 09, 2021, 05:28:55 pm
 Those cylinders are pretty much junk now. They and the heads may have some value towards original 1980 stuff but not much. If original, untouched and in good condition they would have gotten you a good 1980 engine in value.
 
Title: Re: New project 1980 SRX
Post by: 73 RATX on January 09, 2021, 05:34:06 pm
1980 SRX for parts including the motor in classifieds today.
Title: Re: New project 1980 SRX
Post by: yamakid on January 11, 2021, 02:18:26 pm
Those cylinders are pretty much junk now. They and the heads may have some value towards original 1980 stuff but not much. If original, untouched and in good condition they would have gotten you a good 1980 engine in value.

Yep, I couldn't agree more. They are worth scrap prices in those conditions. I scratch my head and wonder why these sleds are abused the way they are.

Good luck on the rebuild, I always loved the Black and Gold!!
Title: Re: New project 1980 SRX
Post by: XCRacer440 on January 11, 2021, 03:17:29 pm
Very cool sled with the twin pipes. arent these 80 srx a pretty limited build or is that another year?
Title: Re: New project 1980 SRX
Post by: jschaffer on January 12, 2021, 03:40:16 am
No, they were the most built of the '76-'80's.
Title: Re: New project 1980 SRX
Post by: SRXS on January 13, 2021, 04:48:07 am
Likely burned down the one cylinder and never got around to fixing it.  Such s shame.  Lots of parts around like others have said.  Nice find!   8)
Title: Re: New project 1980 SRX
Post by: GHenry on January 13, 2021, 02:47:07 pm
I'd be interested in the '76 heads if they are "stock" and not beat to death
Title: Re: New project 1980 SRX
Post by: sdsnocop on January 13, 2021, 11:29:26 pm
Both pistons are in good shape with no evidence of scoring. Even the piston from the damaged rusted cylinder cleaned up well. I have a set of 1980 cylinders ordered but do not know if I can run the 76 heads on the 80 cylinders. The 76 heads are nice and clean but I do not know if they have been planed. How much are the 76 heads worth? I am still working on some leads on a crankshaft and am waiting on condition reports.
Title: Re: New project 1980 SRX
Post by: GHenry on January 14, 2021, 12:44:47 am
Yes you can run '76 heads on any of the 440s' of that era. 

PM me with a price if they are stock 'uncut" and you want to sell, I don't want to be both buyer and seller.
Title: Re: New project 1980 SRX
Post by: sdsnocop on January 14, 2021, 01:20:17 am
Ghenry I will keep you in mind. Right now they are the only set of heads I have. I was not sure if the 76 heads would create too high of compression for the 80 motor or if I would need to go to a fuel octane higher than 91. My sleds are usually ridden at a 6000 feet elevation.
Title: Re: New project 1980 SRX
Post by: jschaffer on January 14, 2021, 03:39:17 am
'79-'80 heads are 8J0.  They are always for sale for about $100 a pair.
Title: Re: New project 1980 SRX
Post by: opsled on January 14, 2021, 12:46:09 pm
Ghenry I will keep you in mind. Right now they are the only set of heads I have. I was not sure if the 76 heads would create too high of compression for the 80 motor or if I would need to go to a fuel octane higher than 91. My sleds are usually ridden at a 6000 feet elevation.

 If you're not racing it you're better off with the stock 1980 parts. The sled will be worth more with the correct stuff and the performance increase won't be enough to warrant the extra headaches.

 I'd sell the heads and anything else worth $ to help pay for the correct stuff.

 Truth is I would probably look for a nice Vmax 600 to buy as a donor and install it's powerplant if I wanted to ride it at all. Cheaper, faster and more reliable. As long as you don't butcher the sled to install it you won't hurt the value.

opsled
Title: Re: New project 1980 SRX
Post by: sdsnocop on May 11, 2021, 03:04:35 am
Finally got back to the SRX project. Ended up with a rebuilt crank. I assembled to motor today except for the water pump which I am waiting for the rebuild kit. I did assemble with the 76 heads but do have a pair of 80 heads in case I change my mind or someone needs the 76 heads worse than I do. I am assembling the sled without the oil pump and plan on pre mixing. I made a deal on a pickup load of SRX parts for $200 which includes a decent 80 hood, 80 tunnel, 2 sets of oem pipes and 4 silencer, 2 good tanks with caps, and 7 tunnel coolers. They are located 425 mile drive away. 
Title: Re: New project 1980 SRX
Post by: sdsnocop on May 14, 2021, 03:32:55 am
Got the water pump rebuilt and installed. Went through disassembled and cleaned both carbs. One had some black sludge, the other was not too bad. Both pilot jets were striped and had to be drilled and removed with a screw extractor. I have the comet clutch disassembled and ready to be cleaned. I need to figure out the jetting for this motor. I have a jetting chart but I need to figure out the jetting change due to the Aaen pipes and running unipods due to currently not having the airbox. I do not know the history of the sled but the mains were very rich at 300's and the pilots were a little lean at an 80. The sled will be ridden at 6000 feet.
Title: Re: New project 1980 SRX
Post by: sdsnocop on June 13, 2021, 05:24:04 am
Made some additional progress on the SRX. Got the chassis cleaned and straightened as best as possible. Straightened the front bumper. Disassemble skid, lube, paint and replace bearings and hyfax. Steering components and skis freed up and painted. Steering was completely froze up. New bearings on jackshaft and driveshaft. SRX is ready for motor install. I cannot find hood hinges so I will need to fabricate a pair. Removing the cat claw style traction devices from the track was a total pain.   
Title: Re: New project 1980 SRX
Post by: Skier76 on June 13, 2021, 01:17:50 pm
Nice work!

I pulled regular studs from a few old tracks I had. What a pain! Even with air tools and lots of penetrating lube.
Title: Re: New project 1980 SRX
Post by: GHenry on June 13, 2021, 03:37:03 pm
Hood hinges from 75? (GPX - Exciter - SRX) on up will work .... should be plenty around, will look better and will sure beat trying to fabricate something.
Title: Re: New project 1980 SRX
Post by: sdsnocop on June 14, 2021, 11:24:37 pm
Installed motor, clutches, and tank. Test fitted the pipes. Tried to start on spray. I have spark but could only get it to fire not run. Hard starting. Upon some thorough thinking and some parts research I learned the pistons for the 77 SRX are different than the 80. The original motor had 77 cylinders with a pair of nearly new Kimpex pistons which are now installed in 1980 cylinders. I hope that is the issue. Hood has had some fiberglass repair but due to the numerous gel coat cracks I am not going to spend a lot of time and effort on it.   
Title: Re: New project 1980 SRX
Post by: GHenry on June 16, 2021, 04:19:21 am
Pistons bore / pin location are no different, wrist pin size is. (76/77 had 18mm pins, the 80 should have 20mm pins)

Porting in the '77 cylinders will be much different than '80 cylinders.

Are the '77 cylinders orginal bore or sleeved?
Title: Re: New project 1980 SRX
Post by: sdsnocop on June 16, 2021, 02:36:14 pm
The motor originally had sleeved 77 cylinders on a 80 bottom end which would mean the pistons I saved would be compatible with with 80 cylinders. I had determined 76 and 77 used a different piston. I knew the bore was the same, I was not aware the pin size was different. I thought maybe the skirt dimensions were different. Thanks for the information it helps a bunch. 
Title: Re: New project 1980 SRX
Post by: sdsnocop on June 29, 2021, 06:33:26 am
Figured out a solution to the broken hood hinges. I used a aluminum brazing rod to build up new material, reshape and drill a new hinge tab. Since I could not get the motor to run on spray I disassembled the cylinders. I thought I may have done something really stupid like installing the pistons backwards. Found they were installed correctly but both o rings were blown out of the groove. I ordered new pistons and found OEM cylinder o rings. I did install the fuel tank and connected fuel lines. The fuel pump tried to pump but was leaking so I ordered a rebuild kit.
Title: Re: New project 1980 SRX
Post by: chris r on June 29, 2021, 10:54:38 am
Looks like you've got a lot of stuff figured out and it's full steam ahead. Lots of Yamaha knowledge in this group.  :)
Title: Re: New project 1980 SRX
Post by: sdsnocop on July 21, 2021, 10:37:57 pm
This thing has had me frustrated trying to get it running. I could get it to fire but not run. I did tear the motor down and resealed the case just in case. The permatex sealant I used was a little old so I redid it with new sealant. However I still could not get it to run. I went out and bought a set of round slide 38mm carbs off from a 91 Polaris 500. I installed them today and success I got her to run. Now to install and fill the cooling system and figure out the proper jetting. The Polaris carbs have 290 mains and 40 pilots.
Title: Re: New project 1980 SRX
Post by: sdsnocop on July 22, 2021, 03:21:51 am
This thing is going to fight me all the way. Installed all the coolant hoses, filled the cooling system. Runs and idles like it should but now is leaking coolant out the cylinder base gaskets. Looks like I will be disassembling the motor again.
Title: Re: New project 1980 SRX
Post by: jschaffer on July 22, 2021, 03:24:52 am
Base gaskets should be a single gasket for both cylinders.  They were still available from Yamaha last year (and they are always on Ebay.)
Title: Re: New project 1980 SRX
Post by: sdsnocop on July 22, 2021, 04:36:51 am
Base gaskets should be a single gasket for both cylinders.  They were still available from Yamaha last year (and they are always on Ebay.)

That is exactly what I have except these are aftermarket not OEM.
Title: Re: New project 1980 SRX
Post by: jschaffer on July 23, 2021, 03:18:07 am
Winderosa is normally just as good as OEM for the base gasket.
Title: Re: New project 1980 SRX
Post by: sdsnocop on July 23, 2021, 08:57:21 pm
I come to believe this thing is possessed. It took me for the first ride I did not plan on. I went through my box of belts and found one that closely fits and installed it. I was running it at idle when all the sudden it revved beyond the 5000 engagement RPM and launched off the front of the trailer and into the back of my 4 wheeler. To be fair I figured out it was my fault. The throttle cable was too short (I have an extension ordered). I must have turned the bars enough to pull the cable revving the motor and launching me off into the 4 wheeler. Damage was minor. I broke one of the hood hinges I had aluminum brazed, bent the front bumper and pulled 2 bolts off one of the rear hood vents. Nothing that cant be fixed except my pride.   
Title: Re: New project 1980 SRX
Post by: XCRacer440 on July 24, 2021, 08:19:52 pm
Sorry to hear that, hope you get the engine issue figured out too
Title: Re: New project 1980 SRX
Post by: GHenry on July 25, 2021, 02:16:10 pm
Quote
but now is leaking coolant out the cylinder base gaskets.


??????????????  Are you sure ?????????????????
Title: Re: New project 1980 SRX
Post by: opsled on July 26, 2021, 12:39:44 am
Quote
but now is leaking coolant out the cylinder base gaskets.


??????????????  Are you sure ?????????????????

 Ya,, That would be pretty hard to achieve.

opsled
Title: Re: New project 1980 SRX
Post by: sdsnocop on July 26, 2021, 05:37:54 pm
You guys are right. I should have known better. The water jacket is not open on the bottom of the cylinder. I found the leak. The water jacket manifold where the coolant enters the cylinders was weeping coolant which was running down the back of the cylinder and running along the base gasket making it look like the base gasket was leaking coolant. This is an easy fix which makes me happy. The throttle extension came today so now I will be less likely to be jumping the SRX off the front of the trailer. 
Title: Re: New project 1980 SRX
Post by: sdsnocop on August 02, 2021, 05:47:12 am
A little more progress on the SRX. I had some clear left over from a previous project so I sanded the hood and painted in some of the missing stripes and portion of the missing SRX decal. I shot the hood with 2K clear. The hood still has numerous stress cracks but it will look good going down the trail and should keep the hood decals from peeling off. I cut down the broken windshield I had, painted the inside of the shield black and shot clear on the outside. I like the look of the short windshield. If it snowed today I would be able take the SRX for a short ride. I will need to order a seat cover and figure out weather the seat foam is salvageable. I still need to find a bumper end, temp gauge, clutch cover, snow flap, carbides, carb filter pods, and tie rod end covers. 
Title: Re: New project 1980 SRX
Post by: XCRacer440 on August 02, 2021, 05:26:11 pm
I think it flows nicely with the black short windshield.  When do you usually start getting snow in the hills anyway?
Title: Re: New project 1980 SRX
Post by: sdsnocop on September 16, 2021, 05:43:30 am
Back to work on the SRX. Brought back a few parts from Hay Days. New belt, carbides which need to be modified to fit, studs and K&N filter pods. I could not find a seat foam for the SRX but brought home an Enticer seat I am cutting down and modifying to fit. Cut a new seat board, reinforced the front seat pan. Rear seat pan was not bad shape. Now I am waiting on a seat cover to install. I have some minor trimming and to glue the foam to the edge of the board and seat pans. I did find a clutch cover I have to pick up locally.     
Title: Re: New project 1980 SRX
Post by: SS440-80 on September 16, 2021, 02:26:25 pm
Going to be super  :D

A tip to get a nice smooth rounding on the seat foam, is to use a angle grinder with a sand disk. But use a fine size of sand disk.
Title: Re: New project 1980 SRX
Post by: sdsnocop on September 21, 2021, 04:45:39 am
Seat is done. Not quite show quality but will work good for a rider. Seat cost me $80, $63 for the cover, $3 for the seat foam and $10 hardware. I did not include the cost of a new electric fillet knife since my old one took a dump. 
Title: Re: New project 1980 SRX
Post by: mitchkem on September 21, 2021, 03:55:00 pm
looks great 8)
Title: Re: New project 1980 SRX
Post by: sdsnocop on October 07, 2021, 04:42:22 pm
Installed new belt, and switch covers. Modified and installed carbides. Found a snow flap and bumper end on line. I still have to fix the small coolant leak on the water intake jacket. I took the SRX for its first run. Unloaded in the newly mowed highway ditch and took her for a rip. Slight bog off the line but pulled hard in the midrange. I have not started tuning yet. The 38mm carbs are straight out of a 500 indy. I am running rich but it is pointless to start tuning since it is 75 degrees and am at 3000 feet lower in elevation than I would be riding the SRX.
Title: Re: New project 1980 SRX
Post by: SS440-80 on October 07, 2021, 07:06:08 pm
So good looking sled  :D