XLT sleeper - Snowmobile Forum: Your #1 Snowmobile Forum

TATE · 01-04-2009, 05:19 PM

I was wondering if i could use my stock components, clutch,and carbs and igniton to bolt up to a 680 ultra case reed motor?

blackgmc99 · 01-05-2009, 09:48 AM

Everything should work but the ignition. your carbs might might be a bit small tho depending what xlt they came off. I just did the same project but I had a complete donor ultra. Still working the kinks out but I think its gonna be quite the sleeper.

TATE · 01-07-2009, 08:24 PM

My carbs i have now i believe are the 34mm ACCS carbs so it hopefully should change my jetting to the bigger engine. But you wouldnt know what the diference is on the ignitions would you?

ridgerunner · 01-08-2009, 03:29 PM

xlt has single cdi box, ultra has 3 individual.... probably more diff. than that, but just swap whole ultra assembly, carbs, clutch, cdi, etc. make it easier on yourself for tuning.

middlman · 01-13-2009, 06:39 PM

I have a very nice 95 XLT SP xtra 12 133.5 out of alaska. motor is now bad, and I have the option to grab a complete running 1996 Ultra SP! PLease tell this would be a drop in replacement?? Would the cooling lines be effected? they look like the ultra has a cooling line through the brakes? If I wanted a quick swap can I ignore this?

ridgerunner · 01-14-2009, 10:39 AM

blackgmc99 did exactly that on his 96 ultra sp into a 97 xlt sp. its a direct swap if you use the ultra carbs, cdi, and exhaust. the cooling lines are a little different cause the ultra has cooled brakes and the xlt doesn't. if you use the xlt overflow bottle there should be an extra line on the bottom that will have to be blocked off. his sled works great, and has tuns of low-end power because the xlt is geared lower than the ultra.... he did the swap himself, so i know he can answer questions about what colant line goes where. all i know is it has to be a sealed loop, but yeah, slight modification and it goes right in.

2000psdbio · 01-14-2009, 10:59 AM

could the slp tripple pipes from the monoblock motor be used with the 680 ultra swap, this is something i have also been thinking about due to reliabily problems with my monoblock. i want to do this but cant justify spending 700 on pipes to get the ultra motor to run better than my xlt motor. But if i can use my 600 xlt pipes i would probably do this conversion. Also, would to 800xcr motor go in a wedge chassis? That would be even better.

ridgerunner · 01-14-2009, 11:20 PM

the pipes from the xlt monoblock are different than those that would be needed for the ultra motor. i would say, if you want to do this swap and have triples for a monoblock, sell them on ebay and buy some good used ones. from everything i have read, when the agressive chassis was released, all 3 (xcr 600, ultra, storm/xcr 800) had engines based on the same '96 ultra 680 case-reed engine, just different top-ends for different displacement. i have wondered the same thing (800 trip. into a wedge), but i haven't seen both engines side by side. so i don't know if there is a different bolt pattern on the case-reed triples in the agressive chassis v. those in the wedge, or if polaris used the same base with just different motor mount plates. the theory is there, but then there could be a problem finding pipes for the 800 trip. into a wedge chassis.

ridgerunner · 01-18-2009, 06:25 PM

he is what has been found so far by the guy that actually performed this swap (blackgmc99). he used the ultra 680 engine, clutch, coils, carbs, exhaust, mounting plates, and belt. the engine is pretty much a drop in system, used the air box from the xlt (only if an sp w/ 38mm carbs) and the ultra's cables for the choke and throttle. the engine sits back slightly once its in the sled, so the belt from the ultra is used. the only semi-issue found (so far) is the cooling system. the 680 case reed and the xlt mono-block have different cooling attachment points and hose sizes. just make a closed, sealed loop. with the testing done so far, the xlt coolers have been plenty.

in the sled

xlt monoblock

in the second picture you can see how the cooling system was attached on the monoblock. this pretty much just got reattached to the ultra engine.

2000psdbio · 01-19-2009, 12:59 AM

The only thing i have noticed is the carbs on the ultra mount lower than on the monoblock motor. But both sleds can use the 38mm roundslide mukini carbs. So it seems that since both sleds were built in the wedge body style that there would be plently of room for the ultra motor with 38mm roundslide carbs to fit into a wegde chassis. I guess thats why you use the ultra mounts. It leaves room for the carbs on the xlt/xcr. You wouldnt nessesarly need the clutch from the ultra just the belt. since all polaris' use the same clutch. Now i think i just need to find a ultra motor with pipes to do my swap...it sounds fairly strait forward.

polaris1977 · 11-19-2012, 11:56 AM

Quote:

Originally Posted by ridgerunner

he is what has been found so far by the guy that actually performed this swap (blackgmc99). he used the ultra 680 engine, clutch, coils, carbs, exhaust, mounting plates, and belt. the engine is pretty much a drop in system, used the air box from the xlt (only if an sp w/ 38mm carbs) and the ultra's cables for the choke and throttle. the engine sits back slightly once its in the sled, so the belt from the ultra is used. the only semi-issue found (so far) is the cooling system. the 680 case reed and the xlt mono-block have different cooling attachment points and hose sizes. just make a closed, sealed loop. with the testing done so far, the xlt coolers have been plenty.

in the sled

xlt monoblock

in the second picture you can see how the cooling system was attached on the monoblock. this pretty much just got reattached to the ultra engine.

i was wondering if you could send me the pictures of the secong picture of the cooling system on the monoblock on the ultra engine (the picture no longer appears in the thread). I am currently working on the same project and would appreciate some help! Thank you.

**BC_Dan** · 11-19-2012, 03:36 PM

You may want to message ridgerunner, he may not be following a thread this old...

ridgerunner · 11-19-2012, 05:37 PM

I don't have any photos of the sled on my computer anymore, and the sled is actually running the XLT motor again. The ultra engine died (not related to the install). I attached photos show the cooling loop of both sleds.

ultra
http://www.polarispartshouse.com/oem...tra-sp-e960678

xlt
http://www.polarispartshouse.com/oem...-system-xlt-sp

If you are able to use the ultra hoses it will make the whole process easier....

polaris1977 · 11-19-2012, 06:47 PM

Thanks. Unfortunately I only have the xlt hoses. Did you use the xlt reservoir and if so, how did you adapt it to the ultra engine? The xlt reservoir has smaller hoses and different configuration. I also asse that I need to add a filler cap somewhere along the line....