Honda XRV Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
Hi everybody I'm new on here & i would like to ask why everybody who fits the trx400 crank to do an electric start conversion on the XR400 also changes the balance shaft ?
i have fitted the trx400 crank & used the original XR400 balance shaft, but here is the hitch - I'm 99% finished on the task !!!! & wondering what the result will be ? will it vibrate ? i know the trx crank has a longer shaft but this will no affect balance,
any body made the same mistake as i would like to know the outcome
 

·
Registered
Joined
·
29 Posts
I'm just about to start pulling the cases together on mine and I'm using the TRX counter balance. The counter balance has to match the weight of the con rod. Any difference and I think it's going shake itself apart. So I'm not taking the risk for the sake of an extra £30, I'm fitting the TRX counter balancer. There's a lot of good info on e-start conversions on the US Thumpertalk website
I presume you know that you need to switch the ECU as well?
Cheers
Gary


Sent from my iPad Air using The Force
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #5 ·
Thanks Gary i do have virtually everything including the ignition box(ecu) etc but not the balance shaft, i do intend to carry on with the XR400 balance shaft as the engine is now back together, i will post the outcome
 

·
Registered
Joined
·
29 Posts
Which battery box are you using ?
I have basically copied the Boechat design and used a 2nd hand KTM battery box.
The battery box I am using is smaller than this as I am intending to use a Shorai battery
This picks up the available mounting points around the left side panel.

Bphoto6.jpg Battery mounting - left panel 1.jpg Battery mounting - left panel 2.jpg Battery mounting - left panel.jpg

I cant post my own photos at the moment as my iPhone has just died!
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #8 ·
"......I'm using the TRX counter balance. The counter balance has to match the weight of the con rod. Any difference and I think it's going shake itself apart...."
All the aftermarket rod kits list the rods as identical between the trx400/xr400, the piston and rings are the same part number as per Honda, the crank is the same bar the longer length outward and the gear for starter drive (this is circular and won't be effecting balance).

I can't find any reference to why the balance shaft is a different weight between the two engines....? Very odd.
 

·
Registered
Joined
·
29 Posts
Same here, we had a break in at Christmas, took my TY175 & expensive Mountain Bike so the contents of two large sheds are now crammed into the garage & I'm gridlocked in there, I can't get to the work bench to build the XR motor.
Anyway, alarms & CCTV going in to sheds etc next week so I should be able to resume shortly.
 

·
Registered
Joined
·
29 Posts
Yes all finished & working superbly, no noticeable vibration from the standard xr400 balance shaft
Bob,
Well done and glad it's all working.
I had mine started briefly on the button but I'm currently still fighting with the wiring. It's not my thing at all, but everything works now apart from the headlight which is just "on" and won't dip. I'm guessing it's just one wire wrong. Just got to shorten the loom by the ECU and then mines also ready.

Can you post some photos, I would like to see how you mounted the battery.
Cheers
Gary


Sent from my iPad Air using The Force
 
1 - 13 of 13 Posts
Top