Bonneville America Forums Forums Technical Forums Performance Mods Top end cruising

I know the limit of the 865 is its top end output but at our speed limit of 70 my bike is 3/4 throttle open in 5th gear. Hardly cruising. At 55 shes bubbing along mind. What can I do to help this? I assume gearing is the answer but what do you wise folks say?

And please don't say buy a T-Bird... If I could afford that I'd have don it already lol :-P

There is no way the thottle needs to be 3/4 open to maintain 70MPH on a flat motorway, unless something is otherwise wrong.

That's a worry Mine will only do 85 - 90 flat out

Lets start with what mod's do you have?....I have no air box, pods only and BC Cocktail Shaker pipes and can cruise at 80-90 mph all day long at bout half thottle...have been above a ton....but if any police are reading this it is all fiction... LOL

I have Harley open pipes running 130 mains and tuned for highest idle but. No airbox mods at all. It's not comfortable at 80 really it has no guts at 70 and above and higher throttle is needed. It just doesnt cruise. Its like it has to try a touch too hard to maintain 70. Its not revinv to hard by any means but i just keep looking for a 6th gear to keep her comfortable. Would a screen make any difference?

There seems to be some confusing things in your post.

When you say it is not comfortable at 80...do you mean it is hard to sit up against an 80 mph wind and a wind screen would help? or the bike just can do 80 mph?...I understand the looking for 6th gear. Coming from a Harley (I had a dyna)I am use to lower rpms.... these bikes are higher rev'ing machines...I am around 4,000 to 5,000 rpm at 80 mph...

I think I solved it. I replaced the plugs, cleaned up all my coil lead contacts, and Its so different I had to re set the carbs. The top of the ht leads where they meet the coils had oxidised in our wet climate because i didnt push the rubber covers on tight enough. Seems a lot better. With the power increase from the new pipes I didnt notice the loss from the ht leads

Do a search on dielectric grease...it will help with the wet stuff...

Dan, if you're lookin' to lower your cruising speed RPMs out there on the Interstates...err, sorry that's right, you're ridin' over there on the "wrong side" of the road there in Blighty, aren't ya...lemme try this again... ...IF you're out there cruisin' along on your single digit M or A roads over there(THAT was better, huh?! ) and ya wanna lower your RPMs, then just purchase a counter-shaft sprocket with one to two more teeth on it, that's all.

The only downside is that you'll find yourself down-shifting into 4th a little bit more when ya hit uphill grades than ya did before, but other than that, I think you'll find this is what you're lookin' for here.

Tiny bit rich actually I will pull the snorkel. No flat spot on mine it's really nice ATM. Shimming the needle.. Ok I have shims but surely that will mean smaller jets?

First pull the snorkel from the air box and see how it runs. You should notice an increase in power but there is usually a flat or lean spot around 1/3 to 1/2 throttle once the snorkel is out. Shimming the needles (raising them) will help get rid of it. Leave the 130 mains for now.

Pulled entire top off airbox and wow she goes. But what if it rains? Do I just remove the rubber bit? Or entire thing?

One shim and it bogs at 1/2 tap instantly is that to be expected and should I continue to tune the pilots?

I shall tinker away and see what happens thanks guys

Well it's running beautifully now so I can only assume it was water or a loose connection somewhere. I've bought some dielectric grease cheers for that advice btw. Couldn't believe the power increase lol.

I would have assumed it would run lumpyer with a fault like this but it felt smooth enough. Mind you I tuned it I expect with the fault so who knows.

Pulled snorkel btw and retuned. Pisses 80 now. It's like new bike.

Either way result!!! Many thanks