Cagllari 47cc Engines For Gas Bike Use?

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 said:

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.

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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 said:

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.

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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

maniac57 said:

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

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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

cannonball2 said:

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.

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CB,

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

Thanks,
Don

cannonball2 said:

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

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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

maniac57 said:

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

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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

16v4nrbrgr said:

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.

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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

cannonball2 said:

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.

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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