XJR engine on 1200Fj 3CX

[sam95]

Hello,

I have a 3CX FJ with a side car with 170000 kilometers now.
As my engine is a bit old, and buy a new side car in france is so expensive, I am looking information about engine swap with 1300xjr engine.

I read on internet that it is possible by modifying few things:
- rear engine mount
- ignition plate
- position of gearbox output pinion

Is there somebody here who have done this mod ?

Also according to you, do you think it is possible to install a XJR engine with injection instead of carbs ?

Thanks from France
Samuel

[ribbert]

Hello,

I have a 3CX FJ with a side car with 170000 kilometers now.
As my engine is a bit old, and buy a new side car in france is so expensive, I am looking information about engine swap with 1300xjr engine.

Samuel, what is it specifically that makes you think your engine needs replacing, 170k is not a lot for an FJ. There are plenty of forum members here with untouched engines well over 200k and still in excellent condition.

Noel

[sam95]

I don't think my engine need replacement now, but I was thinking about that for the future. And we never know if I find a good offer of a cheap XJR engine on internet, I would like to know befor buying if it is a good idea.

At this moment I have problem with start and idle when the bike is cold. Starter turns but sometimes it doesn't engage on the engine and when engine finally run, I need to keep RPM with the throttle during heating of the bike, and begin to ride with light off, otherwise engine stops each time I go to idle.

[FJmonkey]

Sounds like you have two different problems and neither is engine wear. The starter not engaging is a problem I had and fixed with an oil change. The starter clutch did not like the heavier oil and when it got cold the starter would spin but not turn the engine. Try a lighter weight oil and see if that fixes it. The idle problem sounds like you are not using choke to start the bike when cold. Make sure your choke cable is working and the pulling the choke linkage on the carbs. I had this problem when my choke cable broke. It should fire right up with the choke and idle fast. Then once it is warm, take the choke off and all should be good.

[sam95]

I will try new oil

Concerning the choke, the cable is new and works fine I see the lever moving on the carbs.
Unfortunately I use the choke to start but it seems having no effect. When the engine is running moving choke don't increase engine speed. That is why I need to use the throttle to stay around 1500rpm. When engine is hot, if I pull choke the engine stops so I suppose that the choke holes in te carburator are not clogged.......
I don't understand my trouble.....

[FJmonkey]

At least you know it is not an engine problem. The choke linkage on the carbs moves with the cable so that is good. I am not convinced that the choke circuits are not clogged. As you say it seems to have no effect during a cold start. You might have to give your carbs a proper cleaning to fix this problem. As a short cut you could just pull the bowls off and make sure the choke circuits are clear. Does the bike spend long periods sitting?

FYI, to fit an XJR engine you will need to machine/grind some the fins to clear the frame. And the FI will not fit in between the upper frame tubes. You will also need to deal with the drive sprocket being longer, So the chain will not line up without an offset at the front or rear sprocket. 

[jscgdunn]

I will try new oil

Concerning the choke, the cable is new and works fine I see the lever moving on the carbs.
Unfortunately I use the choke to start but it seems having no effect. When the engine is running moving choke don't increase engine speed. That is why I need to use the throttle to stay around 1500rpm. When engine is hot, if I pull choke the engine stops so I suppose that the choke holes in te carburator are not clogged.......
I don't understand my trouble.....

Be sure the choke cable is pulled all the way out and the shaft moving the choke is pushed all the way to the left.  Push on the shaft with your finger to make sure.  If not fully engaged when cold, the choke will not work on some bikes.

[sam95]

I will wait after christmas and remove the carbs again. One colleague said me that it could be a problem of fuel level in the carburator. I am not convinced with that, because the engine works fine when hot.

When I bought this side car it was in a poor condition because it has been parked in a barn, and that barn burnt..... The side was damadged by this fire but not the bike because it was not parked in the barn. The previous owner was doing maintenance on the bike.
After this fire he left the all thing like that during 5 years. Then I bought it in 2012. I Restored it during 1 year. You can have look to my blog for pictures, but it is in french. http://www.sam95.fr/?cat=5
During this restoration I cleanned the carbs by boiling them in water and vinegar. Then I used compressed air.

Maybe there is a much better solution to clean the carbs.

[andresmanuel]

Sounds like you have two different problems and neither is engine wear. The starter not engaging is a problem I had and fixed with an oil change. The starter clutch did not like the heavier oil and when it got cold the starter would spin but not turn the engine. Try a lighter weight oil and see if that fixes it. The idle problem sounds like you are not using choke to start the bike when cold. Make sure your choke cable is working and the pulling the choke linkage on the carbs. I had this problem when my choke cable broke. It should fire right up with the choke and idle fast. Then once it is warm, take the choke off and all should be good.

Thanks for the advice. The starter clutch not engaging in my FJ 1291i I fixed using a lighter oil.