Comet 94

[drgaul]

I am new to the site and thank you for having me. A little about me I am in Texas in the US, I rode Motor cross in the 70s and have always ridden Jap bikes Yamaha R1s etc, then I ran across this site and thought with everything going the way it is (like fuel costs) this is a great idea, and it appears their is a lot of talented guys on this site. Anyway to business, I have not selected a bike yet, I am looking at the idea of maybe a Honda 125-250 cc or similar machine to start with, and we don't have many used Enfield’s over here. I have been nearly everywhere on the site and am enjoying it. But would like to invite reasonable cost ideas for a build. I am looking at the Punsun V twin or the Yanmar clone 10 HP, I have found a supplier for both about $500.00 for the 10 hp and about $1200.00 for the V engine, I read where some builders were having trouble with the Punsun though, we do not have a good supply of small diesel engines here. Also it seems most builders use the Comet 40/44 or some variant of that or an Enfield tranny, has anyone tried the Comet 94 (when I called Comet they told me this was the best for the job), do you prefer the speeder over a CVT? Any ideas on any of this from Bike to tranny would be helpful. I have little time to post so if it takes me awhile to respond, be patient (I have 2 jobs).
Thank You
Dwain

[smokyjoe]

Hi Dwain,

I am only in the process of building my bike, so I'm no expert, but I've been sold on the CVT. I've been driving a Honda scooter using it for driving to work, etc. usually put 100 miles on it the days I ride. It is only a couple of horsepower out of a little 4 stroke watercooled engine, but the CVT uses what little horses I've got to the best advantage by constantly varying the ratio dependent on load. It'll do almost 40 MPH on the flat, and I haven't found a hill it wouldn't climb. I think this is what is needed with a Diesel engine that is designed to run a more-or-less constant speed. I think you'd need a 6 speed gearbox and a lot of shifting all the time to accomplish the same. Lots of Diesel bikes are using the 94 with excellent results. Check eBay often, I've seen some good prices.

Perhaps a 125 or 250 frame may be too light for one of those V twins. I am using a Suzuki GS550 frame for my single-cylinder Hatz which is severe overkill (must weigh 200lbs without engine!) but I don't have another chassis smaller, and it only cost me $40 and smaller junk bikes are few around here. Otherwise I would have used a lighter chassis, but at least I know that thumper engine won't rattle the frame so bad that it'll break in two. I have a Comet 40, definitely not the best choice but it was cheap on eBay.

If I had the money to build whatever I wanted I think I'd use the bigger (14HP?) Yanclone, Comet 94, and perhaps an old late 60's, early 70's Honda CB350 chassis (just for nostalgia's sake). I am looking for something to replace the Honda scooter that is bigger (safer) that is not so apt to be run off the road by stupid car drivers, don't need over 50 or 55 MPH but I want to ride on the highways, but still want 100+ MPG.

Take care,
Brad

[coachgeo]

I am new to the site and thank you for having me. A little about me I am in Texas in the US, ...

Seems TX is taking over lol. Good to have another Texan. Im north TX up above Dallas in Denton and Grayson County (work and home)

[drgaul]

Thank you Brad for the info, when I was a kid I had a CVT on a mini bike and it was fine, it was faster than just the other guys clutch models. The 94 seemed to have a good gear spread (if you will) also having an overdrive was nice, but I am concerned with belt life, I want this thing reliable not on the side of the road all the time, it does no good to get 150MPG if you always are working on it, also my son thinks I am crazy and I want him to see this has merit. Seems like most of these guys are struggling to achieve 55 mph, I thought some of that must be gearing and of course limited HP, I am hoping to avoid some of these issues with this forums help. I will have to check this 14 HP Yanmar clone out, is it a single or a twin cylinder? Is there a problem with the vibration tearing the frames apart? Anyway look forward to talking more to you, are you here in the States or over the pond.
Dwain

[drgaul]

Coachgeo I am in austin have been up your way before, maybe when this thing gets put togeather (if I do good) I can ride up someday for a laugh.
Dwain

[coachgeo]

Look forward to it. Since it will be a long ride stay overnight. You can tent at my rustic home or sleep on cushy mats in my gym. (gymnastics school)

[toad]

well i guess Texans are coming out of the wood work..i too hail from the lone star..Panhandle,, Lubbock home of the Red Raiders..
t

[coachgeo]

well Im not a "real Texan" I just play one. Only been here just shy of two years. Am a bit of a southerner in general though.

[drgaul]

Well I to am not originally from TX; I was born in MO in the Ozarks but have been in TX since 1981. So now we have all the Texans together, does anybody know of any good suppliers for Diesel engines? Enfield still builds bikes, we have a dealer here in Austin and there is one in Dallas. I went to the one in Austin Friday, they have two engine designs one is basically unchanged from the 50s or 60s, I believe they call these AV something’s or pre-units? Anyway trans and clutches are still available and local. I have a Yamaha XS 650 twin, I was going to restore it but it will cost more to bring it back then to buy a good one, I may use this for my project, but it is heavy 451lbs an Enfield is 370lbs, of course the 650 engine is probably 150-200lbs, I took it out today to look it over, think I got a double hernia by lifting it out, long story short its trashed. So does anyone know about this Punsun twin? Are they any good? Or where I can get a Lombardini or a Ruggerini reasonable. I would prefer a twin if I use this bike over a V design (less to move around). Ideas are welcome.
Dwain

[coachgeo]

Locomotivebreath may be intrested in selling one of his engines. He has a few of different ones and parts of several that could be combined to build one. I helped him pick up one of them in roundabout ways.

He's a member here.

Enfields trannys do not have a great reputation. Consider a CVT tranny or a Ultima and a belt drive to it. Chain drive from ultima or CVT to rear sprocket. or a honda gold wing direct shaft drive. Ask locomotive breath about those. He says you can get them reasonably from folk who build trikes and dump the shaft drive. Watch fleabay for any of these.

[toad]

another place you can look is the construction equipment rental stores. i have noticed that several pieces of equipment have the small i, 2 or 3 cyl diesel engines. lot of times they replace the engine that has a lot of hours regardless if there is anything wrong with it.

the refer units on semi truck trailers use a diesel, the ones i have looked at have a Lombardini for power. lawn equipment also has some diesel power. the small tractor co kubota makes other equipment with diesel

there is also a member here that has the v-twin and i believe he is a dealer.. can't remember his name right off hand. he seems to have a decent price for them.. he has a thread somewhere in the forums..

t

[drgaul]

Thanks for the info Toad and Coachgeo, I'll check it out.
Dwain

[smokyjoe]

Hey Dwain,

I am up in Taxachusetts, but I used to work in El Paso whether that makes me a wannabe or former part time Texan or not. But I do ride a horse and wear boots if that's worth an armadillo in the cactus!

The folks who use a CVT have for the most part gotten real good mileage out of their belts, if the gearing is set up right. Some have added weights and played with the springs to get the engagement right, others have used them as is. It might be comparing apples to bananas, but my little Honda is going on 4,000 miles and there is little noticeable wear on the belt. I think that Crazy Jerry has about 7000 miles on his belt on a Comet 500 with a Yanclone 10 horse. tnfan on this board is importing those 14 or 15 HP units along with the Punsun v twins and 10 horse jobs, he's in Tennessee. I've seen enough Punsun V twin failures on this board and elsewhere to scare me, although I admit I have absolutely no experience with them or have never even seen one "in the flesh" so I guess my opinion isn't worth a darn! Hopefully by now they've ironed out the weaknesses.

I've heard of engines being listed on Craigslist but I've always been a day late. If there is a State surplus auction near you that might be a bet, I saw a small ride-on roller in Connecticut that went dirt cheap and had a 2 cylinder Lombardini. Also some of the big commercial mowers use Kubota 3 cyl. engines, I think that is what my D950 came out of (for a future shaft drive project). I think that some refers use the Kubota 3 cyl engines, worth an ask around. The 950 I have is pretty lightweight, not much heavier than my little Hatz, but is liquid cooled and 25 horse.

Good luck,
Brad

[pietenpol2002]

Dwain,

Here's another option (if you don't mind a rather long bike. And then you'd have to have either a 90 degree gearbox for a chain drive or a chain/belt offset for a shaft drive). The inline oriented engine would give you that diesel Moto Guzzi effect. But the option of having a reverse would be great for when you go to add the sidecar.

http://tinyurl.com/ndqewp

Ron

[drgaul]

Thats pretty funny Brad and a lot of good info. Have you ever thought about the little kid in school just learning to spell Massachusetts, thats like Swortsanager?? Ya gotta feel for the little guys, I am not making fun of your state, just got to thinking about it when you said Taxachusets?? Any way very good info, reading on the site they mentioned the Punsun v twins cracking the cases and cranks breaking, and said to stick with the smaller 812 cc or smaller (looking at these supliers one engine will say 812 cc and another with the same bore and stroke will say 835 or 836 cc). I know from the past (I have been known to work on diesels Yes Olds 350s and 6.2s) that they are sesitive of their timing and water in the fuel, either will destroy the engines and thought this may be some of there issues and just was not sure. Also I have heard that over there in China and other areas that their quality control doesn't exsit, but at the same time Yanmar is supposed to be a great engine and on this site they talk about the Yanmar v twin 750cc engine, I am confussed, they all look the same just different colors and stikers. Anyway I will check latter this week with the guy you told me about that inports and see what he has.
Thanks again
Dwain
P.S do you really like the smell of diesel? I am doing this because I can get all the Veg oil used I want and am tired of making middle easterners rich and then have them use the money to kill our sons.

[drgaul]

Ron; no sidecar, I am the guy that said when he was a teen he would only drive a V8 and now ( shamefully) I have a V6 pickup and Gulp I I even had a 4 cylinder before, these life changes take time Ron I may never be able to do the sidecar thing, I have thought about an inclosed reverse trike with a rabbit 1.6 diesel though and of course with a/c, I live 10 min from Hell down here, another 105 degree day with no rain, and when it rains its a sauna, gotta have a/c. Hey that engine on Ebay the EKO looks like another Punsun and this one is from Canada (must be an imported engine). Good idea though thanks that gives me another supplier to talk to.
Dwain

[roverthetop]

my $.02... my punsun bikes are doing fine, but here's the catch- my first punsun build (in the green-ish kawasaki) i was lucky. i ordered 3 more straight from china, and upon receipt, started breaking them in. one went into my sporty (cvt), one i will ONLY use as a generator, and the 3d i've not decided if it'll go into my softail. seems the quality control is lacking. all 4 shake, rock, sound and feel completely different. the 812cc seems the most stable to me. it's a roll of the dice on these engines. i may opt for a briggs vtwin, liquid cooled (26 hp) next, but SPENDY. as are the lombardinis, which i've used. lomb is good, a bit tall (backbone modification, stretch, etc. in the orange dnepr) and parts not so easy to come by simply because when lomb was bought, (is it kohler who bought them?) the sales/ service people know nothing about them. i had to ring italy if i remember right, to order a mundane part. ug.
cvt's take getting used to. odd experience for a long time rider. when building with a cvt, ensure you've a way to tighten the belt for wear... my engines can move slightly forward. the ultima seems a good choice for a gearbox, as i have one for the softail. chain primary, belted final, rsd.
my opinion for what its all worth.
B

[drgaul]

roverthetop, great info, thanks. Hey are all these V twins Punsun? or are there other MFG's building the same engine? Has any of your Punsuns failed and how do you tell the 812 from the others before you buy? I do believe at this point for ease of instalation I will use a Comet 94, unless there is a better choice to use. I'll check out Briggs to.
Thanks Dwain

[drgaul]

roverthetop, just checked out the Briggs 26.5 hp great reviews, you were right not cheeeep $5000.00 +, 10 hp Hatz $1800.00.
Dwain

[roverthetop]

Dwain,
If you'd like more specific tech advice, and decent buys, a ring might be best. pm me or write roverthetop at earthlink.net for a number. PDT, USA.
I had forgotten about Kipor as well. May be decent... dont know? Been thinking of testing one of those to see how well it fairs. Keep in mind most smaller diesels haven't variable injection timing however.
Also, i'm told Yanmar's v-twin (vertical) can be tipped sideways for horizontal use with minimal modifications. Many sites say it can't, but i've seen it on a few bikes.
punsun, winsun, whateversun... probably the same, or VERY similar. all are the same casting, with the exception of bore size i believe.
if i had fairly unlimited budget, it would be briggs 26hp, ultima 6er (chain primary, belted final, rsd) on a (harley) aftermarket frame. Briggs are Tier III i believe, parts available, proven, decent workhorses. (again, IMHO)

Also, the ebay engine probably is punsun. with their "new" gearbox. anyone in the US, DONT import it from canada. if you're going thru the hassle already of importation, get it from the factory in china and get rid of several middlemen. i can help if you'd like. advise should be free.

also, 94c isnt necessarily "ease of installation", mate. very specific measurements needed, and take up some room, both front to back and side to side. be aware of that.

none of my punsuns have failed other than the starters... ALL of the starters. but i chose which to go into bikes carefully. 2 of 4. 50%. not superior odds. if i decide to put the 3d into the softy, i'll do it with the understanding i WILL QUITE PROBABLY blow it up.

tnfan is importing the engines from my understanding. if he knows what he's got (812, 836, etc) and can run them and know what he's listening for, that may be a good way to go. at least a better shot at getting a decent one???

best of luck, mates.

brett

[smokyjoe]

Some good advice, Brett

I like the idea of the adjustable mounts for the CVT.

Are you using any fuel preheating running SVO in your bikes? I've run my engine on the bench on veggie, switching over from dino diesel when it's hot. The injection pump is bathed with hot oil and it ran fine as far as I could tell, but maybe a bit quieter? I eventually plan on heating the tank and fuel filter somehow and have a "starting tank" and selector valve if I run it in the winter, but for summer use I was wondering if any extra heat is necessary.

Thanks,
Brad

[coachgeo]

Some good advice, Brett

I like the idea of the adjustable mounts for the CVT.

Are you using any fuel preheating running SVO in your bikes? I've run my engine on the bench on veggie, switching over from dino diesel when it's hot. The injection pump is bathed with hot oil and it ran fine as far as I could tell, but maybe a bit quieter? I eventually plan on heating the tank and fuel filter somehow and have a "starting tank" and selector valve if I run it in the winter, but for summer use I was wondering if any extra heat is necessary.

Thanks,
Brad

IMHO get it running well and have no engine faults and a known compression measure before converting anything to WVO. You need to watch your compression over time to help evaluate if your starting to coke up the engine. Other suggestion is; like we do here.... diesel bike questions are asked of diesel bike nuts with the most experience while learning also from the hacks still learning just like you . Im a hack very much a low level hack btw. Same for WVO- ask those questions in places where WVO folk hang out to learn from their experts and hacks (some WVO board). Me Im a hack in WVO world but no expert. Been around it for 7+ years now.

Those Really deeply in the know on WVO engines say that if your engine gets less diesel sounding on WVO thats actually not good. means your not getting full burn of the fuel. Running WVO should include change to the ignition timing to match the characteristics of the fuel burn. Very few do this. Old diesels designs could tolerate it. Newer you get.. the more thats not true. Least thats what it seems to be after all these years of reading discussing. So take it as a grain of salt.

[roverthetop]

brad,
i use dual tanks- most are harley style splits. also gives me a place to put the fuel pump for the veg and the inline heater- "vegtherm". start and stop on (bio)diesel, and switch when its up to temp, just as i do in my ram cummins. do make sure its well broken in, and that your fuel lines aren't old school rubber. the engine needs to be warm enough to run well on the veg. keep that in mind. inline heat is mainly for colder weather to let the veg flow more freely. DO NOT use partially hydrogenated. only non-hydrogenated.
the adjustable mounts are necessary for cvt use.
b

btw, you'll find me on several veg boards as well, just to know.