Directions how to install engine kit on kent la jolla cruiser

bajaracer1

bajaracer1

New Member
Installing Engine Kit on Kent La Jolla
This is meant to bring light to a few specific modifications that have to be made to build this bike.
The Kent La Jolla is a great bike to start with! Its lightweight aluminum frame feels great at speeds and is easy to handle on turns. Plus it’s a great looking bike, and did I mention it’s SO LIGHTWEIGHT!
1. Shaving the rear fender is required to make room for the new chain. You will have to remove the rear wheel when you’re installing the rear sprocket. This is the perfect time to get a hand grinder and grind a channel in the fender to make room for the chain. From the bottom side start grinding 4 inches above the frame, and from the top start grinding 3 inches from the top of the frame. Make sure to wear proper eye and ear protection!

2. Since this bike has a smaller shaped frame the carburetor does not fit into the frame. You will need an offset intake manifold to move the carburetor to the side of the frame. Simply un-bolt the stock manifold and bolt on the offset manifold. Having an offset manifold also gives your engine more bottom end power!


 
3. When installing the rear sprocket only use the black rubber insulator on the inside of the rim. The outer insulator will cause the sprocket to sit too close to the coaster brake arm and cause binding.


4. The gas tank installation is very sensitive. The frame of the bike is very thick where the rear bracket mount on the gas tank is located. The fix is easy. Take the bracket and slide it onto the rear gas tank bolts upside down, so that it follows the contour of the gas tank. Then place the tank on the bike as close to the steering tube as possible without touching it. From underneath tie two zip ties around the frame of the bike and the silver bracket (which should be installed upside down). The zip ties will hold the tank in place. !!!NOTE: These gas tanks are very weak so when tightening the nut DO NOT TIGHTENS THEM MUCH!!! Or else you will pull the threaded studs out of the gas tank and cause leaking after a few miles of riding. You should be able to move the gas tank by hand when it tight. That’s how loose it should be.
 
5. Lastly the Kent La Jolla has a thick bottom tube. This means you will have to use the supplied U mount that comes with your engine kit. Un-screw the front studs that come in the engine mount area and screw in the U mount bracket. Make sure you use some blue or red Lock Tight on the threads since they tend to raddle out over time.


YOUR DONE! CONGRATULATIONS, ENJOY YOUR NEW LIGHTWEIGHT ALUMINUM MOTORIZED BICYCLE!
 
It's good of you to post this info and these photos. They can be helpful to newbies with this particular model and can offer hints to those with other bikes as well.

Now I'm afraid I'm gonna nit-pick a bit. But I don't think I like your solution to brake arm clearance. You've weakened the sprocket mount by leaving out the outer rag. It's a mechanism that takes a lot of abuse and should be as stout as possible. I'm inclined to suggest that you re-mount it with the outer rag and use bolts with a shallower head. Plus bend the brake arm a bit outward if necessary.

I feel like I'm raining on your parade. But that's not the intent. Good post and nice work. Good looking bike, too. You just might want to re-think that one issue.
 
Nice work, and good post.. Looks like a good way to get up and running pretty quickly on that style of bike.

Unfortunately though I have to side with Blue Goat on the rag joint.. My thinking says putting the sprocket directly against the spokes may lead to broken spokes more quickly. If it were an option, I'd probably prefer to go with a hub adapter instead in that scenario.
A strip of muffler hanging strap, or even the copper version used for plumbing could also be a better alternative to the zip-ties you used for the front tank mount. However with the way you've put it together doing that would be a 5 minute minor job.
 
Yes a sprocket hub adapter is a far superior solution to the rubber pieces that come with all kits. I would recommend this.

Using the second rubber piece does not work well because it moves the sprocket too far away from the hub. This causes the sprocket not to sit inside the groove of the hub that currently holds the sprocket centered and inline. If you use the second rubber piece then you will have an extremely hard time getting the sprocket to sit centered and inline. Also you cannot bend the brake arm enough the clear the second rubber piece. I’ve tried. I’ve build 150 of these bikes already.

Both ways have their good and bad attributes, but the best solution is to buy a sprocket hub adapter. That’s what I use!

 
bluegoatwoods said:
It's good of you to post this info and these photos. They can be helpful to newbies with this particular model and can offer hints to those with other bikes as well.

Now I'm afraid I'm gonna nit-pick a bit. But I don't think I like your solution to brake arm clearance. You've weakened the sprocket mount by leaving out the outer rag. It's a mechanism that takes a lot of abuse and should be as stout as possible. I'm inclined to suggest that you re-mount it with the outer rag and use bolts with a shallower head. Plus bend the brake arm a bit outward if necessary.

I feel like I'm raining on your parade. But that's not the intent. Good post and nice work. Good looking bike, too. You just might want to re-think that one issue.
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while I am in principal inclined to agree, my little neighborhood bike has its rag joint set up like this, and with over 500 miles it has not budged an inch. I just had the sprocket off to change it (crappy china sprocket wore out) and the spokes and hub looks absolutely fine. It is not a powerful bike, which may attribute some its well being, however I do regularly ride the bike at over 30 mph. It is also very easy to get the sprocket concentric when installed this way. It is by no means the best way but its not the worst either.
 
The kit I ordered came with the spark plug coming straight out of the top center of the head. Luckily I had a slanted one laying around but that might be another consideration, depending on what comes with your particular kit.
 
When I was looking for a bike to start with, I saw so many pictures of motorized versions of this particular bike that I figured it was an ideal bike to start with.

I still think this, though I wish I'd seen this thread first (I would've gotten on the road a week sooner had I known I'd need the offset intake manifold.)

Anyway since this thread is the one that led me to this awesome forum I thought I'd share a pic of "Lola" - hope that's ok!

picture.php


Cheers!
 
bajaracer1 said:
5. Lastly the Kent La Jolla has a thick bottom tube. This means you will have to use the supplied U mount that comes with your engine kit. Un-screw the front studs that come in the engine mount area and screw in the U mount bracket. Make sure you use some blue or red Lock Tight on the threads since they tend to raddle out over time.


YOUR DONE! CONGRATULATIONS, ENJOY YOUR NEW LIGHTWEIGHT ALUMINUM MOTORIZED BICYCLE!
Click to expand...

Very nice motorized bike. Same thing I'm building. With a few changes on my build. The fenders are of poor quality, basically and accident waiting to happen. I would consider ditching them before you get hurt. Second the gas tank I'm not using. I purchased a rear pannier rack and a seat rack to mount on my build. I'm going to fabricate a custom gas tank to go under the seat rack and over the rear pannier rack. A much safer set up. Thirdly I wont be using the sprocket assembly that comes in the kit. Ordered a clam shell and 40 tooth. Fourth, The chain idler is another accident that will surely destroy your entire rear wheel when it twists into the spokes. A better option is to run a flat bar of aluminum or steel with the idler placed on it. Have it stretched between the 2 left rear bike frame members. That configuration would be impossible to tear out your spokes. Just a few of the mods I'll be doing on my ride. There's many more I'm doing but for another time, maybe after I learn how to upload some HD picks of the work in progress.
usflg
 
bajaracer1 said:
Yes I think I did sell one locally.
Click to expand...

I know for a fact you sold one locally... Because a POS bike that was brought to my shop for repairs matches the pics you posted perfectly, (right down to the zip ties you use to hold the gas tank on)! :-{

He brought it to me to fix because it started falling apart only a few days after buying it from you, & he said he had been calling you for almost two weeks about it (& you were ignoring his calls)! :(

The rear wheel was almost fully locked up, the gas tank was falling off, the engine was loose (& leaning to the side), the chain had fallen off several times while riding it... all in the first week of buying it from you!!

You really need to learn how to build a reliable bike before you sell anymore of them... (& stop bragging on this forum about giving directions to others about how to build them).

It's shady builders like you (who sell POS's like this to unknowing people (& then unplug your phone when it breaks) that are giving these bikes a bad reputation! :-{

SERIOUSLY... Learn how to build quality bikes before someone gets hurt! :(


EDIT.... Now, just to be clear, the thing that i'm really pissed about is the fact that you refused to return the guys calls... THAT'S what's giving legit vendors like me a bad reputation!
I can't tell you how many people I've talked to about these bikes that have the same story about POS bikes breaking down & shady 'CL' sellers who disapear after it's sold. (it's a very common story, (obviously)) :-{

I had to go way out of my way when this guy brought your bike to me to reassure him that I wasn't going to rip him off either. (I hate feeling like I have to do that to save these bikes reputation from POS builders).
 
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Watch what you say because it's easy to judge situations when your involved with 1 party. First of all I never turn off my phone and I'm always available. Second I am an engineer and have been building cars, motorcycles, bikes Etc. since I was 15. I currently design custom made brake and suspension upgrades for race cars. I make master billet prototypes that get mass produced and sold around the world! I Think I can install a motorized bicycle kit onto a bike. All the bikes I build get driven for 3-5 miles before I sell them as new. I have never sold a bike that Needed any adjustments or repairs. Please do not make those types of posts when your ill informed to the entire situation.
 
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