[grahampaul]

 just did a compression check,75 psi.so of with its head methinks.can someone give me a link to a nice composite one so many out there and i dont need a bad one.any thing else i might need while i am in there.thanks.

[stinkwheel]

I've always used the Hitchcocks ones which are made by cometic if memory serves correclty.

If nothing is obvious when you get in there, pop the exhaust valve out and check the seat is still firmly in place, I've had them come loose before.

[grahampaul]

hi,can you give me  a link as to which one i need.its for a bullet 65(i think!) 2004.i have taken a look but cant be sure exactly.and yes will definatly be giving the head a good checkover.

[AzCal Retred]

Cometic in blue. Order two, shipping should be the same. Make that shipping count! 

https://accessories.hitchcocksmotorcycles.com/1693?qty=1&continue_url=https%3A%2F%2Fwww.hitchcocksmotorcycles.com%2Fpartsbook-pages%2F8655#
PART No. 142617
GASKET, CYLINDER HEAD, 500cc & 535cc BULLETS
£10.50
India OEM

https://accessories.hitchcocksmotorcycles.com/accessory-shop/Classic-Models-Indian-Made/7675PART No. 42333C
HEAD GASKET, COMPOSITE (WITH FLAME RING), 500cc & 535cc
£15.50
Cometic composite gaskets may be used without gasket jointing compound or with a light coating of compound on one side only.Product Details
For the older 500cc (& 535cc) "classic" engines this gasket is an American made product using modern materials and incorporates a flame ring. We have developed and tested them in both competition and on the road.

[stinkwheel]

Remember to order your paper gaskets at the same time, they are so cheap it's not worth cutting new ones out. You'll definately need a base gasket if you're checking piston and rings. Maybe rocker cover gaskets (although I tend to re-use those a lot)

That said, if you can do without the bike for a few days, it would make sense to strip and diagnose it first, THEN put the order in in case you need any other parts. It's probably not just the head gasket because if that was blowing enough to reduce compression, you'd see from the outside.

[grahampaul]

Cometic in blue. Order two, shipping should be the same. Make that shipping count! 

https://accessories.hitchcocksmotorcycles.com/1693?qty=1&continue_url=https%3A%2F%2Fwww.hitchcocksmotorcycles.com%2Fpartsbook-pages%2F8655#
PART No. 142617
GASKET, CYLINDER HEAD, 500cc & 535cc BULLETS
£10.50
India OEM

https://accessories.hitchcocksmotorcycles.com/accessory-shop/Classic-Models-Indian-Made/7675PART No. 42333C
HEAD GASKET, COMPOSITE (WITH FLAME RING), 500cc & 535cc
£15.50
Cometic composite gaskets may be used without gasket jointing compound or with a light coating of compound on one side only.Product Details
For the older 500cc (& 535cc) "classic" engines this gasket is an American made product using modern materials and incorporates a flame ring. We have developed and tested them in both competition and on the road.

thanks for the link,have ordered up a top end set,

[grahampaul]

Remember to order your paper gaskets at the same time, they are so cheap it's not worth cutting new ones out. You'll definately need a base gasket if you're checking piston and rings. Maybe rocker cover gaskets (although I tend to re-use those a lot)

That said, if you can do without the bike for a few days, it would make sense to strip and diagnose it first, THEN put the order in in case you need any other parts. It's probably not just the head gasket because if that was blowing enough to reduce compression, you'd see from the outside.

thanks for the info,have ordered up top end set for now.i blame the faulty decompresser myself the
e is oil around the top fin with no other leaks to see. sure hope you got pics of this.oh well time to find where the head bolts are located

[grahampaul]

ran another compression check today cold was eighty,ran the engine till warm which i couldnt do the last time and got 150.gave it a few minutes checked again  150psi.
just befor this i removed a duck bill from the breather tube,how anything could breath through that i dont know.
what would cause to high a reading if indeed it is?.
on  another note the comp lever came,wrong fitting for the cable.oh well try again they may be nice to me and change it.

[AzCal Retred]

Standard 6.5/1 C.R. reads are about 110-115 PSI. The 8.5/1 C.R. "hi-dome" pistons are in the 150 PSI range. Other causes are carbon build up on the piston & head. Severe oil intrusion can possibly affect these numbers. Maybe the pressure gauge went south?

[stinkwheel]

Compression can disappear entirely then come back again as soon as they are started. It's happened before to me more than once after a protracted period of not being run and at least one other person has reported similar. Not 100% sure why, maybe a sticky valve, maybe a ring sticking in the lands?

[grahampaul]

i have no reason to dought the gauge,i do have a differant type i will try later to be on the safe side. if its due to carbon buildup ithink it would need a fair amount to raise it that much.lookng down the plug hole the piston looks a bit black like its been running rich for a while.possibly the duck bill had something to do with that.its clear at the exhaust end.15,ooo on the clock, been stood for a while and no history of the bike or any work carried out.i wonder if there is any way of measuring the hight at tdc to the plug hole to see if its a high dome?

[grahampaul]

Compression can disappear entirely then come back again as soon as they are started. It's happened before to me more than once after a protracted period of not being run and at least one other person has reported similar. Not 100% sure why, maybe a sticky valve, maybe a ring sticking in the lands?

all good food for thourght,will know when i take the head of at some stage,at the moment am gaging for an mot.

[stinkwheel]

It's easy to check if the breather is working. Just stick the end in a jam jar of water with the engine running and see if you get a steady stream of bubbles. I actually measured the flow through the one on my 350 and it was flowing 1.8l per minute at a fast idle.

[grahampaul]

It's easy to check if the breather is working. Just stick the end in a jam jar of water with the engine running and see if you get a steady stream of bubbles. I actually measured the flow through the one on my 350 and it was flowing 1.8l per minute at a fast idle.

thanks for the input,what do you think of the one wat valve in the system.

[stinkwheel]

Seems to work about the same, I measured 1.7l/min on the same bike with a diesel fuel 1 way ball valve, which is probably within the margin of error for my crude measuring system. What would be more interesting would be how quickly it responds to pulses. Ideally, I'd check the crankcase pressure but that would be a fiddle and there are other things I should be doing really. Pretty confident both give you a slight vacuum in the crankcase which is what you want.

Having had a duckbill breather get folded over on me once, I can assure you that a bullet engine will find new and unexpected places to leak oil out of if it pressurises the crankcase!