J-Engine 410cc Thread
- Thread starter sam2019
- Start date
Bungy the cam chain? And miss out on hours of trying to fish it back on the crank sprocket? Where's the fun in that!Your about to get a pleasant surprise
Have you got the tools and a rh side cover gasket?
And Bungy cord to hold up the cam chain
Just drop a cam carrier bolt at the very end, that's how I get my fun.
Hi guys, after stripping the engne down to get the Hunter ready for installation of the BB kit I've measured the ring gaps and they are.25mm for top 1 and .35mm for top 2. These gaps seem a little tight based on what I'm reading here.
Are these ok or should I gap them a little wider. Not sure of the best method if I have to do that. Any advice is welcome.
Are these ok or should I gap them a little wider. Not sure of the best method if I have to do that. Any advice is welcome.
You are right, just a bit too tight.
I think in thou, I would be happy with 12 and 15 ( 0.3mm and 0.4mm).
A very fine file( like a "points file")
Held in a vise and you move the ring end by hand, be sure to check for burs.
I think in thou, I would be happy with 12 and 15 ( 0.3mm and 0.4mm).
A very fine file( like a "points file")
Held in a vise and you move the ring end by hand, be sure to check for burs.
Thanks for the info.
Regarding piston skirt to bore clearance I'm looking to check mine. Should I take the spec from the LS10 motor seeing this is a 410 bore and the piston looks like an RE OEM piston?
I saw a published picture in the LS10 pages where the clearance is shown as 0.015mm and 0.04mm. Then I saw the link to the wassnor info pages and they quote nearer 0.07mm.
It could be they are quoted as performance pistons.
What clearance is aimed for when making the kits? Also I was wondering if there is an engine heat difference between the J and LS410 as the J series is fully air cooled with no oil cooling. I tried to find data on the Jseies for the clearances but I can only find the service limit.
Am I over thinking this?
I wouldn't worry about the difference between the 2 engines.
Wossner would be forged alloy and need greater clearance.
The Boring process as done in India is not high tech but perfectly adequate in this case.
The tec would finish off by honing until the piston just falls through the cylinder, I mean just!
If it needs force or doesent fall by itself it would be honed until it does.
I doubt the tec would have the ring set and therefore would not be checking end gaps.
Customers usually don't like to see the small marks left behind by inserting the rings or the ring package opened.
The running in period finishes off the fit.
Wossner would be forged alloy and need greater clearance.
The Boring process as done in India is not high tech but perfectly adequate in this case.
The tec would finish off by honing until the piston just falls through the cylinder, I mean just!
If it needs force or doesent fall by itself it would be honed until it does.
I doubt the tec would have the ring set and therefore would not be checking end gaps.
Customers usually don't like to see the small marks left behind by inserting the rings or the ring package opened.
The running in period finishes off the fit.
yes. the 410 outsells the 500 4:1 and none ever had any problems. its not a new kit anymore so my guess would be accumulated 100k km have been driven with these kits. The only seizing we ever had was with a 477 Himalayan kit and that is a forged piston.
I thought it was about time I gave my fitting experience with the 410 kit. I hope this will be further reassurance to others considering this upgrade.
After receiving the kit I decided to measure everything for peace of mind and everything was spot on. This was a great learning exercise for me having an expert show me how to do it while confirming what I did. The results were that the liner was very accurately bored with a nice hone cross hatch. Piston to bore clearances were well within spec for the 410, great job guys.
The only thing I had to do was gap the rings as top 1 and top 2 were a tad tight ( 0.2mm and 0.3mm respectively) I opened them up to 0.3mm and 0.4mm. Using the LS410 specs as a reference, this indicates that 0.2mm and 0.3mm is good but I took the advice from Sam and the guys.
Fitting was straight forward enough and took a couple of afternoons to complete the job, and yes I had to re-thread the cam chain a couple of times LOL. I did find in the end that if you keep the cam chain guide fitted you can let the chain just hang and it doesn't seem to come off. One bonus I didn't drop anything into the engine.
Out of interest I compared the weight of the pistons with rings and wrist pin fitted and the 410 was just 35g heavier. Not sure if that weight difference will have any affect on vibration.
I also fitted the Hitchcocks cam at the same time and modified my open air filter cover by fabricating a larger snorkel to cut the noise a little whilst letting as much air in a possible.
The bike started after a couple of cranks and settled into a nice idle after a few minutes. I let it run for 30 mins just ticking over to give it a full heat cycle and ECU reset. After cooling down I restated and give it a few gentle revs, definitely pops a little on decel and the tappets are slightly louder than I remember but I guess that could be the high lift cam as I adjusted them perfectly. After running in for 300 miles I'll check the clearances and head bolt torque again.
Unfortunately I won't be able to ride for a couple of weeks as we're away for a while but I can't wait to try it out on the road.
Watch this space ....
After receiving the kit I decided to measure everything for peace of mind and everything was spot on. This was a great learning exercise for me having an expert show me how to do it while confirming what I did. The results were that the liner was very accurately bored with a nice hone cross hatch. Piston to bore clearances were well within spec for the 410, great job guys.
The only thing I had to do was gap the rings as top 1 and top 2 were a tad tight ( 0.2mm and 0.3mm respectively) I opened them up to 0.3mm and 0.4mm. Using the LS410 specs as a reference, this indicates that 0.2mm and 0.3mm is good but I took the advice from Sam and the guys.
Fitting was straight forward enough and took a couple of afternoons to complete the job, and yes I had to re-thread the cam chain a couple of times LOL. I did find in the end that if you keep the cam chain guide fitted you can let the chain just hang and it doesn't seem to come off. One bonus I didn't drop anything into the engine.
Out of interest I compared the weight of the pistons with rings and wrist pin fitted and the 410 was just 35g heavier. Not sure if that weight difference will have any affect on vibration.
I also fitted the Hitchcocks cam at the same time and modified my open air filter cover by fabricating a larger snorkel to cut the noise a little whilst letting as much air in a possible.
The bike started after a couple of cranks and settled into a nice idle after a few minutes. I let it run for 30 mins just ticking over to give it a full heat cycle and ECU reset. After cooling down I restated and give it a few gentle revs, definitely pops a little on decel and the tappets are slightly louder than I remember but I guess that could be the high lift cam as I adjusted them perfectly. After running in for 300 miles I'll check the clearances and head bolt torque again.
Unfortunately I won't be able to ride for a couple of weeks as we're away for a while but I can't wait to try it out on the road.
Watch this space ....