Cagllari 47cc Engines For Gas Bike Use?

[dbledsoe]

Did a search but the Google based search engine for this forum is less than useful i.e., returning no forum related messages but plenty of the typical Google distraction ads. Be that as it may, the little Cag 47cc engine seems a viable alternative to the typical Grubee China girl type engine, it certainly seems better made (I bought one via Amazon with the included clutch drive/transmission). My reason for buying is to enable me to stay within my state laws regarding engine size restrictions for gas powered bicycles, in my case 49cc or smaller to qualify as a not required to be a registered motor vehicle, and build on a better quality engine.

I have done a lot of internet searching and found the Cag 47cc engine is typically a pocket bike engine. I am fine with that because there are a lot of direct bolt on performance parts for the engine (some of the expansion chambers I typically see being billed/sold as suitable for the China Girl engine were actually developed/built for the Cag 47cc pocket bike engine). Still, there are a ton of bolt on performance parts reasonably priced for the Cag 47cc engine, enough so to grab my attention.

Down side to it? I will have to custom build a mount to get the engine into a bike frame... but then again, we often have to do the same with mods to the China girl mounts if the bike frame we choose to build on doesn't fall within the some what narrow window of the China Girl engine mounts. Just wondering out loud here if anyone else has used the Cag engine in a gas bike build or looked into it?

Thanks for any feedback.

Don

Thanks,
Don

 

[maniac57]

Cags are one of the most disappointing engine designs ever built. They look so good, yet are so unreliable and finicky...they run GREAT! For 5 minutes at a time between teardowns.
Cags have broken more than one two stroke tuner.
If you DO manage to keep one running long enough to ride it, gear it for RPM as they like to rev.

 

[dbledsoe]

Cags are one of the most disappointing engine designs ever built. They look so good, yet are so unreliable and finicky...they run GREAT! For 5 minutes at a time between teardowns.
Cags have broken more than one two stroke tuner.
If you DO manage to keep one running long enough to ride it, gear it for RPM as they like to rev.

Maniac,

Thank you for your response. Clearly not a favorable response for the Cag 47cc though.

I am curious, what are the specific negatives about the Cag that make it a 5 minute motor (that is a unique term that I like)? Trying to understand you correctly, is it poor design? Bad electrics? Lousy materials? Junk carb? Lousy reed system? Can you be more specific, and please don't say all of the above? That is not helpful. It would seem there has to be one or two, maybe more, specifics that make it "one of the most disappointing engines...". It would be helpful to know what those specifics are now that I find myself the owner of one.


Thanks,
Don

 

[cannonball2]

I completed a Cag shifter bike not too long ago and had a decent experience with it. Its rather peaky but when geared right worked well and had plenty of rpms for a good top end. If you go with one stay with the little stock motor. The staged motors are super problematic. Mine is still running fine for the new owner.

A much better choice is the 49cc commercial style engine also used in the Cateye style pocket bikes. I am finishing a build with one of those and so far have found it to be a super great little engine. They can be bought for $75 shipped now on ebay. Coupled with a 3:1 reduction they make a good starting point for a simple build. I am running a 3speed hub with mine.

 

[maniac57]

All the Cags I have messed with were used, so this may not apply as strongly.
ALL had carb problems, like crappy shut off valves and leaky bowls/fittings, and all had reed valve issues. For some reason, they would just quit, and swapping reed valves was only thing would get them running again.
When they did run, I had constant gasket failures and bolts falling off.

I would try the Cateye mentioned by cannonball

 

[dbledsoe]

I completed a Cag shifter bike not too long ago and had a decent experience with it. Its rather peaky but when geared right worked well and had plenty of rpms for a good top end. If you go with one stay with the little stock motor. The staged motors are super problematic. Mine is still running fine for the new owner.

A much better choice is the 49cc commercial style engine also used in the Cateye style pocket bikes. I am finishing a build with one of those and so far have found it to be a super great little engine. They can be bought for $75 shipped now on ebay. Coupled with a 3:1 reduction they make a good starting point for a simple build. I am running a 3speed hub with mine.

Cannonball,

Might you have an ebay link to the 49cc commercial style engine you are referring to? I have been searching ebay for the last hour. I can come up with Cateye engine parts but no complete engines.

Thanks,
Don

 

[cannonball2]

Heres the link. Great engine! http://www.ebay.com/itm/2-stroke-en...ash=item1e8ba6a76b:g:Ir8AAOxyedRTdkoj&vxp=mtr

Heres a link to the build. This has worked out well with the exception of having initially chosen too high an overall ratio. I used second as the factor to determine the numbers, which left third really too high. Am waiting on a smaller sprocket for the secondary drive side. That should finish it out nicely. In my build at least this is the smoothest 2stroke I have had. http://motorbicycling.com/showthread.php?t=60263

 

[KCvale]

Heres the link. Great engine! http://www.ebay.com/itm/2-stroke-en...ash=item1e8ba6a76b:g:Ir8AAOxyedRTdkoj&vxp=mtr

Well that's a pretty slick little engine.
Pull start and no internal reduction.
What is the spacing for the transfer case bolts?

That TC looks like a typical HS 4-stroke and maybe a 4G would bolt right on?

Heres a link to the build. This has worked out well with the exception of having initially chosen too high an overall ratio.
I used second as the factor to determine the numbers, which left third really too high.

Nice job with the oversize sprocket on the Nexus 3-speed.
I love those simple internal shifters.

Am waiting on a smaller sprocket for the secondary drive side.
That should finish it out nicely.
In my build at least this is the smoothest 2stroke I have had. http://motorbicycling.com/showthread.php?t=60263

Sweet.

If the TC mount holes are the same as a 4G a 10G would fit on there nice with factory 4G holes as it wouldn't have anything in the rear in the way, and then just use the SBP BB freewheel and standard rear derailleur or internal shifter with standard sprockets to keep the pedals.

A 5:1 4G with 9T out should even work for a direct drive.

Has the diaphragm carb given you any issues?
What is cool with them is you don't need to keep the gas tank above the carb. The issue is when it fails and even gravity feed don't work.

Just a tip...
With no manual clutch lever you can run independent brake levers, but regardless try your 3-speed shifter on the left.
It's upside down but far easier to operate as just part of a short left grip.

This a 2-stroke 7-speed rotary shifter with clutch lever but that could just as well be an independent brake lever or nothing on the left.

Just something to try for a bit easier operator controls ;-}
And again well done!
http://motorbicycling.com//www.pinterest.com/pin/create/extension/

 

[cannonball2]

Thanks KC!

I have a kit with the 49cc HS 4stroke and the reduction from it fits this engine perfectly, meaning the belt versions should too.
I have had no issues with the carb. It is adjustable for mixture unlike the US Walbros, and they even sent the tool with the engine. I bought a replacement carb as backup for $10 shipped! At that price why even bother to clean/rebuild?

My first shifter bike years back had the shifter flipped to the left, but it was never completely second nature(I'm a slow learner).

I finally got some high$$ brake pads and the bike stops great though I wish the twin pull had been the long handle version like the sellers pic showed.

As soon as I get the ratio settled it should be a fine rider. The 22t sprocket should be here tomorrow.
The little engine is breaking in nicely and starts runs very consistently.

Very NICE graphics by the way!

 

[dbledsoe]

All the Cags I have messed with were used, so this may not apply as strongly.
ALL had carb problems, like crappy shut off valves and leaky bowls/fittings, and all had reed valve issues. For some reason, they would just quit, and swapping reed valves was only thing would get them running again.
When they did run, I had constant gasket failures and bolts falling off.

I would try the Cateye mentioned by cannonball

Because, as you state, your experience is, "All the Cags I have messed with were used..." I will dismiss your experience. I am starting with a new Cag 47cc engine with transmission. And I know enough about Chinese small engines to know their carbs and reed valves are often lacking. So my engine will be built by tossing the factory carb and reed valve setup to be replaced by a Delorto SHA 15.15, new intake manifold, and two different after-market carbon fiber reed valves. With only those changes I will try the Cag motor to see how it might actually perform. On hand, but waiting in the wings, is the Stage I cylinder, head, holed piston, full circle crank kit, and a 19mm Walbro carb.

If we're going to talk realistically about an engine's merits perhaps we should have some actual experience with an out of the box new version, ya think?

Don

 

[dbledsoe]

I completed a Cag shifter bike not too long ago and had a decent experience with it. Its rather peaky but when geared right worked well and had plenty of rpms for a good top end. If you go with one stay with the little stock motor. The staged motors are super problematic. Mine is still running fine for the new owner.

A much better choice is the 49cc commercial style engine also used in the Cateye style pocket bikes. I am finishing a build with one of those and so far have found it to be a super great little engine. They can be bought for $75 shipped now on ebay. Coupled with a 3:1 reduction they make a good starting point for a simple build. I am running a 3speed hub with mine.

CB,

Might you have posted a thread on your Cag shifter build? I searched but couldn't find a link.

Thanks,
Don

 

[cannonball2]

Heres the link Don. Its rather long but covers my experiences and thoughts on the Cag.

I was down at my friends yesterday that has the bike and the only problem he has had was a broken recoil which is fairly common. He is a mechanically inclined guy and understands the bike and its engine well. It may not have faired so well otherwise.

http://motorbicycling.com/showthread.php?t=58707

 

[KCvale]

Thanks KC!

I have a kit with the 49cc HS 4stroke and the reduction from it fits this engine perfectly, meaning the belt versions should too.

Yep, it's for an HS 142F-1G tapered shaft clutch attached engine, so you have lots of transfer case choices for that 2-stroke engine.
Cool!

I have had no issues with the carb.
It is adjustable for mixture unlike the US Walbros, and they even sent the tool with the engine.
I bought a replacement carb as backup for $10 shipped!
At that price why even bother to clean/rebuild?

Exactly, but it's all work regardless, and seldom at a friendly place and convenient time for a repair, but then again, so is the life of a 2-stroker ;-}

If you want to keep a backup for that whimpy chain drive transfer case get a hold of me, I have 3 new ones for like $35 I'll never use on anything I build, I bought the gasbike kit for the HS 142 and other parts and use 4G's.

My first shifter bike years back had the shifter flipped to the left, but it was never completely second nature(I'm a slow learner).

Very NICE graphics by the way!

Hehe, thanks, I have a decent enough camera and a pretty good sense for details and the photo tools to 'make a pic say 1,000 words' as it were.

It was a bit awkward for me to turn a rotary the same way as a throttle, top towards you to go faster, when a shifter turns top away from you to go faster.

With it on the left, they work the same, top towards you is faster on both sides.

It's been easy since I started doing that, actually awkward if it's not now hehehe.

Good luck with it and have fun, you did good ;-}

 

[maniac57]

Because, as you state, your experience is, "All the Cags I have messed with were used..." I will dismiss your experience. I am starting with a new Cag 47cc engine with transmission. And I know enough about Chinese small engines to know their carbs and reed valves are often lacking. So my engine will be built by tossing the factory carb and reed valve setup to be replaced by a Delorto SHA 15.15, new intake manifold, and two different after-market carbon fiber reed valves. With only those changes I will try the Cag motor to see how it might actually perform. On hand, but waiting in the wings, is the Stage I cylinder, head, holed piston, full circle crank kit, and a 19mm Walbro carb.

If we're going to talk realistically about an engine's merits perhaps we should have some actual experience with an out of the box new version, ya think?

Don

Valid point. Don't say you were never warned.
Check out this thread for Cag info: http://motorbicycling.com/showthread.php?t=42509&page=23

 

[dbledsoe]

Heres the link Don. Its rather long but covers my experiences and thoughts on the Cag.

I was down at my friends yesterday that has the bike and the only problem he has had was a broken recoil which is fairly common. He is a mechanically inclined guy and understands the bike and its engine well. It may not have faired so well otherwise.

http://motorbicycling.com/showthread.php?t=58707

CB,

Thank you so much for the link to your Cag build. A lot of good information! Do you still have the Cag build and, if so, might you update your build thread to provide a several months since build review?

I am new here. I like the forum and appreciate the individual build threads, with one exception. Once built what happens to your creation? It was once important enough to you to take time to shoot pics and post build messages. And then, too often, it is simply forgotten. Why is that? Granted we can't take a build into perpetuity but maybe a six months or a year later status of build would be helpful.

Just some out loud thinking.

Don

 

[dbledsoe]

Valid point. Don't say you were never warned.
Check out this thread for Cag info: http://motorbicycling.com/showthread.php?t=42509&page=23

Maniac,

Thank you for the link to that thread! That link lead me to another link that lead me to another with some great info about the various Cag performance stage mods. And that leads me to conclude the Cagllari is a fine engine to modify for performance provided one has some understanding of the baseline engine weakness, and the crankcase is a major weakness, specifically the cylinder studs (or lack there of of studs).

So I ordered a spare stripped crankcase and will build the stage motor from that, to include larger cylinder & head studs of at least grade 8.

Don

 

[cannonball2]

By all means helicoil the cylinder stud threads then you might have a fighting chance. I would change to SAE at that point. The studs are not the issue but the case threads.

As I said in the last post my friend has had the bike for the last several months and it is serving well. Its main use is as a pit bike for the various events he visits a couple of times a month. He rides it every where he goes once he gets there rather than use his truck. It has gotten a fair amount of use.

I seem to have the MB sickness pretty bad as I cant seem to stop building the things. A quick count shows I have 10 gas and Ebikes with two builds waiting. From time to time I am forced by space and the wifes constant commentary to eliminate a few, so I don't know how some have faired. A lot are collecting dust while I'm involved with the others. I suspect a lot of builders are similar. In the middle of all this I am building a small diesel powered inboard fishing boat.
Crazy!

Open a thread for members to give account for their long term experiences, if there is not one to bump up. A quick search should find it.

 

[16v4nrbrgr]

Check out my build using a cag engine on a motobike, it's a good engine when geared correctly and bolted together very tight with some longer head bolts.

 

[dbledsoe]

Check out my build using a cag engine on a motobike, it's a good engine when geared correctly and bolted together very tight with some longer head bolts.

Can you provide a link to your build that uses a Cag engine? For some reason the site search engine doesn't work very well for me. I get a lot of unrelated Google stuff when I use it.

Thanks,
Don

 

[dbledsoe]

By all means helicoil the cylinder stud threads then you might have a fighting chance. I would change to SAE at that point. The studs are not the issue but the case threads.

As I said in the last post my friend has had the bike for the last several months and it is serving well. Its main use is as a pit bike for the various events he visits a couple of times a month. He rides it every where he goes once he gets there rather than use his truck. It has gotten a fair amount of use.

I seem to have the MB sickness pretty bad as I cant seem to stop building the things. A quick count shows I have 10 gas and Ebikes with two builds waiting. From time to time I am forced by space and the wifes constant commentary to eliminate a few, so I don't know how some have faired. A lot are collecting dust while I'm involved with the others. I suspect a lot of builders are similar. In the middle of all this I am building a small diesel powered inboard fishing boat.
Crazy!

Open a thread for members to give account for their long term experiences, if there is not one to bump up. A quick search should find it.

CB,

At $25 for new engine crank cases I can afford to experiment several times over with larger studs, helicoils, SAE studs, and other stuff. A lot of pocket bike racers seem to mod the Cag engine successfully, don't see why I can't too. I have the original stock engine, which will remain as stock. I also have two full circle cranks, HP cylinders, heads, pistons, etc. to build a hot rod engine so why the heck not? If one blows I am out what, a hundred bucks? I can handle that in the name of speed.

I have never been a cautious person. No need to start now. As some say; if some is good and more is better, then too much is just enough.

Don