Bonneville America Forums Forums Technical Forums Custom Corner Bonneville Clutch Cover questions

SO I got a clutch cover.

Now I have a few queries, that I presume the answers are easy but I just wanted to check with you - better mechanics than me!



1. The bonneville crank breather pipe - why doesn't the Speedmaster/ America have this?

2. The clutch mechanism cover that fits the standard bonneville cover - see mount holes - again why doesn't our bikes have this? will it be a problem if I don't install one?

3. The cover inside the America cover near crank - what does it do? Is it only for oil flow which I presume is not needed if I swap covers?

hi,
I will try to answer your questions as best as I can.
first of all I assume you have a 790cc engine, because I think the 865 engine uses a different setup for the crankcase breather.
1. The bonneville crank breather pipe - why doesn't the Speedmaster/ America have this? .
the answer to this is the america/speedmaster do have this pipe, on your pictures, the cover on the right is missing the breather pipe.if you have just taken the cover off of your bike it may still be attached to your bike, have a look.it passes back through the crankcases above the clutch and is connected to the black rubber hose that goes to the air filter housing.

2. The clutch mechanism cover that fits the standard bonneville cover - see mount holes - again why doesn't our bikes have this? will it be a problem if I don't install one?
not sure that I fully understand this question, but I think
the answer to this is, the cover on my america is the same as the pic on the right so I assume we dont need this part.

3. The cover inside the America cover near crank - what does it do? Is it only for oil flow which I presume is not needed if I swap covers?
this plate houses the crank end of the breather pipe and is only used on the america/speedmaster, if you look closely you will see that the breather pipe on the bonnie cover is already in its housing, so no plate needed.

I hope I have helped answer your questions, feel free to ask if you need more info, please let us all know how you get on with this as I am sure there are more of us considering this mod
good luck . steve.

Thanks Steve,
Difinantly no centrifugal breather on the crank or breather pipe inside America cover, my bike only has the spacer plate pictured below. Also where the hose enters the crank case (above clutch) there is just a plate covering it. The manual doesn't tell me anything. My bike model is a 2005 America 790cc, so maybe this model doesn't have it for some reason??




Also the plate inside America cover just has rubber clamped behind it. I think it 'might' be a vibration dampner to stop the cover bolts coming loose or make it quieter. That may be what the Standard Bonneville cover has attached near clutch lever arm (circled below) - what do you think???

Is that the new style engine case? Mine is an '05, has a breather hole near the top with a rubber grommet. Are you trying to put an old style cover on a new case? I don't think it will work.

hi again.
well it appears your crankcase breather has been removed, looking at the blanking plate thats been fitted ( above clutch ) it dosent look like a home made part, so do we assume its an aftermarket mod ?. could it be part of an emissions reduction system.
my bike is a 2005 america 790 and has the breather intact, I would expect our bikes to be the same so this makes me think that it is a mod of somekind, how is your engine breathing is there a crankcase breather fitted someware else ?.
the plate inside the america cover, could it be a vibration damper or is it used to surpress noise, I dont know.
same goes for the plate in the standard bonnie cover???.
maby someone else on here can shed some light on this matter...
sorry to not be any more help, but please let us know what you find out and how you get on, as I am very interested as to what is going on with your bike.
good luck steve.

There is still the breather pipe / filter attached to the crank case,but it's just covered by that plate pictured. Without taking the clutch and plate off (will do when clutch wears out) I assume the breather either enters th crank case behind plate or just lets it breath via the clutch case area?

The parts are all stock Triumph, I've had the bike since new.

The cover fits! I just left the rubber / alloy plate bit out for 2 reasons - I have D&D's so engine noise is no problem - and it weighs a bit so theroetically my bike is now faster!! hahh

SO....How does she look with the bonnie cover on there? Lets see some pics! (I've seen your bike before and frankly I'll take just about any excuse to see more pics of it! )

It looks great in my opinion, it makes the engine look slimmer from the top. I always thought it looked wider on the left side but it's now centred also.

Sorry for the suspense but I also have a few other mods in progress at the moment (new battery box relocated to centre, head light and indicators and cutting off frame tabs etc.) so it may be a week before I can get any decent photos as it's in the shed stripped down.

Rest assure I will clean it up and get some pics ASAP.

Here are some photos, all coming together like I wanted. I've done 50km on the new set-up with no problems.

That looks great! Really nice. Do those come in chrome?

Gives it a more old school look.

Cheers Dave, it does come in chrome for T100 model. I got the stator and sprocket cover in brushed aloy also as I'm going for the old school look that Ian mentioned.

This is another view I like about this cover, the fact that it makes the engine slimmer and centred in the frame.

yeah, I like that

Dang, Chris. That really does look good. Very good job on your accomplishment.