Forum

[Davie Hall]

I should have said mine is running one of our hosts upgraded conrods

[Adrian]

If you're running one with a UK made big end and European or Japanese main bearings, you have sorted one of the main reliability concerns. The other one which crops up with the engine occasionally is cam follower failure, where the foot snaps off at the stem. For some reason the factory used thinner stems on the lean burn cam followers than in the classic Bullet engine.



There is one key element besides a carb and exhaust replacement which makes a real difference, which will shortly be revealed to you!



A.

[simon]

thanks for clearing that up.

[Jojje]

Three years ago I had read enough horror stories about Electra big end and had our host's con rod kit fitted with new main bearings. The mechanic said bearings and rod were as new (40.000 km's) but I gave him the green light as I knew he was about to retire... Anyway, he did a splendid job putting it all together: less vibration and better idling. 54.000 km's so far.

[Adrian]

Simon,



just to confuse matters the Indian factory also used the Electra name for a home-market 350 Bullet. This had what was basically an ordinary 350 Bullet engine, but with crank mounted electronic ignition and no contact breaker assembly. Early versions had CDI ignition, later models had the same TCI ignition used on the Electra-X lean burn model, very late versions had the 5 speed gearbox and electric start.



A.

[Bullet Whisperer]

Hi Davie, Adrian has pretty much answered your question, but I would add that the last Electra X I had here for tuning had covered around 17000 miles when I stripped the top end to shorten the barrel and modify the piston nearly two years ago. The big end felt as new at that point and the owner informed me not that long ago that it is still running well and going a lot faster than it did originally. I must ask him what the current mileage is next time we speak. I could be wrong, but I think if all is well in the bottom end when approaching 20,000 miles, it is probably a good one and out of the danger zone. That said, perhaps bottom end failures occur at widely varying mileages, perhaps some owners who have had big end troubles on these machines could let us know the mileages their machines had reached when the big ends failed? Cheers, Paul.

[Davie Hall]

Hi whisperer, I wish I could agree with you about a 20k bike is out of the danger zone. My electra X big end failed at something like 19700 miles. At least I hope mine is sorted now because apart from the conrod kit it is now running top quality main bearings. There wasn't anything wrong with the original main bearings when I rebuilt it, I just thought it better to replace them when it was apart.

[Bullet Whisperer]

Thanks, Davie, perhaps such failures are more random - or maybe around 20,000 miles is the danger zone. I will set the ball rolling by starting a new thread asking owners what mileage any failures came at and see what we get. Regards, Paul.

[Adrian]

I have heard conflicting reasons quoted for these failures, our hosts reckon it was the lack of proper outer track, as it uses a Japanese style big-end in a hardened con-rod, while Henry Price, who has rebuilt a few Electra-X cranks reckons it was the hardening on the crank-pins that went - mostly on engines fitted with various go-faster kits. The same crank seems to have been fine on the 350 AVLs, though.



@ Davie, I thought Bullet Whisperer might reveal the most transforming part of the tuning equation. As he didn't, but he has in the past, I feel it's OK to reveal that the Redditch "S" profile cams really let the engine rev, whereas the AVL cams cause valve bounce at 5,800 rpm. Others have had good results with the normal Indian Bullet cams and the "R" profile cams. Just watch inlet valve to piston crown clearance, the piston might need a small valve pocket cut into the piston crown. B.W. also offers a squish band modification.



A.

[jefrs]

Question - to summarise tuning then, one raises the compression ratio (barrel and piston), cams, bearings, carburation and exhaust; do we know the final compression ratio?