my 1974 alsport tri-sport

lonleyinml

lonleyinml

#1
#1
Hello everybody
I just bought my first trike. It is a 1974 alsport trisport. I saw one of these for the first time when I was 19 years old and I have wanted one every since 30 some odd years ago. It seems to be mostly intact I still have most of the rupp engine but it has been replaced with a 440 Yamaha air cooled sno mobile engine and the wiring is a mess. but I'm satisfied with the condition here are some pix. And yes it is street legal. If anyone has any information that can help me with parts technical info ect... do not hesitate to drop me a msg or email I would appreciate any help that this forum can offer:wink:
 
steven Durham

steven Durham

#3
#3
I think I should be able to help with your project. Take a look in my photo section and you will see lot's of Tri-Sports there. I was a dealer in 1972 through 1974
This is the Trike that was on Craigslist in Yakima, Washington right ?
here to help . Steve Durham Portland, Oregon :scooter:
 
lonleyinml

lonleyinml

#4
#4
Hi Steve,
Yes it is the one from CL in Yakima it is the 2XXcc or something like that I have the original rupp engine but all that is there is is the long block with clutch no carb no tins or ign. It has a 440 Yamaha in it now. I need a head rest, seat upholstery and a speedo. Also my throttle and handlebar controls are of of a yamaha motorcycle. I'm sure I will have a million questions as I get into this thank you for your offer of help
Jeff
 
lonleyinml

lonleyinml

#5
#5
More on my alsport tri-sport project

Update:
I have gotten to get a better look at my trisport it is a 1974 RTS 290 and then did some research on the motor and found out it is out of a 1976 GS 440 Yamaha snowmobile. I have some questions about this engine : 1. This engine appears to have oil injection, is it feasible to utilize it in this application 2. This engine is manual start only but I think it has a place for a electric starter. I may be posting this in the wrong forum if you can help me with this please let me know, and does anyone know a good snowmobile forum that could help me. thanks in advance
Jeff :smile:
 
steven Durham

steven Durham

#7
#7
Tri-Sport

lonleyinml said:
Update:
I have gotten to get a better look at my trisport it is a 1974 RTS 290 and then did some research on the motor and found out it is out of a 1976 GS 440 Yamaha snowmobile. I have some questions about this engine : 1. This engine appears to have oil injection, is it feasible to utilize it in this application 2. This engine is manual start only but I think it has a place for a electric starter. I may be posting this in the wrong forum if you can help me with this please let me know, and does anyone know a good snowmobile forum that could help me. thanks in advance
Jeff :smile:
Click to expand...
If the oil injection is set up right it should work but they have been known to fail and although the pre-mix is a pain in the butt it works great always. When I got my RTS I bought a brand new Kohler K 440 cc 2AS engine it is rated at 50 HP and it had the starter ring gear and I added the starter and relay. I got the motor from Groth Products Inc. out of Crystal, Minnesota I don't know much about the Yamaha engines . Your posting this in the right place on the forum and the Tri-Sport is the only connection I have ever had with snowmobile engines. Steve :scooter:
 
lonleyinml

lonleyinml

#10
#10
Update Again :
I finally slowed down enough to ride my trisport for the first time today and that thing really hauls ass !! the tires are very weather checked so no highway riding I just blasted around the buildings and the parking lot at work when I first started it up it was only running on 1 cylinder and once I got rolling the 2nd cyl kicked in and I grabbed a handful of throttle and we were off to the races I backed out of it (no rear brakes and very Little front brakes) . Any way when I brought it back in to our shop I noticed it was leaking fuel. A quick inspection revealed that the secondary clutch had rubbed a hole in the fuel tank because the fuel tank had no support brackets of any kind. I repaired the tank and I am trying to figure out how allsport supported the tank originally. I also figured out after bleeding the rear brakes that the master cyl is leaking and appears to be bypassing internally ( it wont pump up under any circumstances ), so I have some work to do :smile:
 
steven Durham

steven Durham

#12
#12
On the tank I did the same thing . I cured it by putting a 7/8 inch maple block about 3 inches long under the tank and used a 1 1/4 pipe strap to hold the block in place under the tank and on top of the left frame rail the pipe strap held block there with 2 1/2 inch screws When I got my Tri-Sport it had been taken apart 20 years ago and I did not have an assembly manual like Mac's Steve :scooter:
 
steven Durham

steven Durham

#13
#13
On the tank I did the same thing . I cured it by putting a 7/8 inch maple block about 3 inches long under the tank and used a 1 1/4 pipe strap to hold the block in place under the tank and on top of the left frame rail the pipe strap held block there with 2 1/2 inch screws When I got my Tri-Sport it had been taken apart 20 years ago and I did not have an assembly manual like Mac's Steve :scooter:
 
lonleyinml

lonleyinml

#14
#14
Well, I have been puttering around with my trike all winter long knee surgery has slowed me down a little bit but I'm on the mend plus we had a pretty brutal winter here. I have however formed a pretty good Idea of what I want to with this trike near and long term.
For the short term I am going to use the parts I have to get this thing in running order. I'm going to install the factory safety kit for the suspension arms and double shock the rear too.
As far as the long term goes I plan to acquire a Kawasaki ex500 (ninja) water cooled twin modify it for remotely operated push button air shifting and install it in the tri sport with split radiators in the existing air intakes of the cowl if possible and move the rear brakes to one of the foot pegs to free up a hand location for a clutch handle. so please let me know what you think of my plans
 
steven Durham

steven Durham

#15
#15
Good to hear from you again. I like the addition of the water cooled engine for your riding area's summer heat is very often on the high side.
I am not sure about having the brake on the foot control as with the Tri Sport you are always turning and twisting the pegs into you and away from you.
How about thinking about a thumb throttle on the right hand and the brake on the left hand and the clutch on the right side like a lot of big bikes do.
Have you looked into liquid cooled snowmobile twins ? To me no gearbox can compare with the constant variable ratio that a belt system provides.
And I know that I was never happy with the stock brakes and if your working at highways speeds it is a well below par system. Thats why I went to 10 inch disc and dual piston calipers. I did the wheel change to 10 inch from the start of the rebuild I just think it looks better and I was able to get better tire selections for the D.O.T. approval.
If I had it to do over I would of extended the frame in front about 3 inches.
Please keep a picture log and let us know how you decide to go.
Steve :scooter:
 
lonleyinml

lonleyinml

#16
#16
Hi Steve,
I am going to use the Alsport foot boards instead of pegs so I envisioned that mounting a foot operated master cylinder under a foot board would be fairly straight forward. I have thought about keeping the variable drive but I have already had primary clutch issues (not completely opening) and I'm worried about a lot of clutch maintenance. My snowmobile buddies say its a lot of work to keep the clutches working and also I'm gonna try to make this a daily commuter / driver so I think a transmission would increase engine life (and highway speed) and the motor would not be at wide open throttle all the time just to stay at highway speeds. Please give me your opinion of this you have done a lot or road riding on one of these. also if you could send me the part #'s for the rear brake hardware I would appreciate it
jeff
 
Last edited:
steven Durham

steven Durham

#17
#17
Hi : I never have used the foot boards on any of my Tri-Sport trikes. About the Clutch maintenance the snowmobile rides have some issues of the wet environment but I never had any operational problems with my drive systems if I kept them properly dry lubed.
As for the high RPM's highway speeds that is the thing that killed so many of the Rupp Centaurs that were air cooled and oil injection.
I do worry about the manual clutch and chain drive I am sure you would want to go to a heaver drive chain. And how strong is the Holtan Differential ?
For the brakes I bought good Go kart billit 1 inch hubs and used Martin 10 inch disc 3/16 inch thick MCP710 solid disc or the slotted disc # MCP710S Biggest issue with mounting the calipers is the the tri-Sports differential is supported by just two bearings and this allows a lot of flex and the disc tend to not run 100% true so the calipers need to be floating in style of mounting or they will bind the pistons of the caliper.
The calipers are all rated for off road use but that didn't stop me I bought Wilwood Draglite model of calipers but over at www.aps-karting.com they sell the full line of Martin Custom Products.
Steve :scooter:
 
lonleyinml

lonleyinml

#18
#18
Thanks again Steve for all your help
Have you never used the alsport foot boards ? or simply not seen a set yet?. I am not completely against the snowmobile drive train but the first phase of modding and driving it will determine that since I will be going with the current Yamaha 433. I too worry about the diff, is there an alternative? I am also going to go to a taller tire but I'll have to possibly extend the fender struts for it to fit. what kind of road speeds should I expect?.
About the rear axle bearings I am thinking of putting bearings on both sides of the frame bearing flange or trying to find a double row bearing
 
steven Durham

steven Durham

#20
#20
Set it up right

lonleyinml said:
Thanks again Steve for all your help
Have you never used the alsport foot boards ? or simply not seen a set yet?. I am not completely against the snowmobile drive train but the first phase of modding and driving it will determine that since I will be going with the current Yamaha 433. I too worry about the diff, is there an alternative? I am also going to go to a taller tire but I'll have to possibly extend the fender struts for it to fit. what kind of road speeds should I expect?.
About the rear axle bearings I am thinking of putting bearings on both sides of the frame bearing flange or trying to find a double row bearing
Click to expand...
I have seen the foot boards but never sold or used any. With the Holtan differential it will take the power applied by the belt system but if the use of a clutch engagement it may be hard on the aluminum casting. And to make the bearing support into a 4 bearing set up the axle stub is not long enough. All I was saying was the need to have the caliper floating to compensate for the untrue condition this makes the rotors have a slight tilt.
I did make new fender mounts when I went to the 10 inch wheels.
As for speed my stock gearing but with the 10 inch wheels my top speed was 69 MPH . Try running on the interstate next to a big semi truck and you will feel the human pucker power. LOL
Steve :scooter:
 
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