Triumphrat

jrn · 09-09-2009, 04:15 PM

Ok Having issues with the girl this year, leaky tank, leaky carbs, now a hot start problem. It does have a Boyer, but I don't think it's spark,it feels more like a compression issue. Setting the valves I still think there's more play in the rockers than I like, but I have no experience to base my opinion. What are some of the things I could check. Thanks again

Plewsy · 09-09-2009, 05:01 PM

Hi jrn, it could be a tight valve which is staying slightly open when hot.
Or you mentioned your carbs had been leaking,
if they are rich this would also cause poor hot starting.
I would not think its the ignition if it starts ok cold.

KADUTZ · 09-09-2009, 06:37 PM

You said you had a carb problem if you had them off to rebuild did you use the fat Oring part #70 9711 or the skinny one in most rebuild kits.
When the hard starting is happening are the carbs HOT to the touch? If so you have vapor lock. When using the fat Orings the intake manifold and carb are insulated from each other. On my bikes the space is about the thickness of about 2 business cards.

jus a thought

jrn · 09-09-2009, 06:56 PM

It would be nice if it was a carb problem. I do know from taking the carbs apart that the O-ring is very thin. also both the gaskets on the intakes are very thin as well. Should I invest in thick O-rings and Manifold gaskets as I am buying new rocker box gaskets because they are in bad shape.

Also, how can I test for a sticky valve.

Thanks again

KADUTZ · 09-09-2009, 07:30 PM

Fat is where its at. If your carb and manifold touch you will have a problem with hard hot starting. If you want to spring for new manifold gaskets you can, I wouldnt. They cant be very much money and the Orings should be much either

Jus my pinion

K

Plewsy · 09-10-2009, 08:15 AM

Gaskets are a good investment, cheap and fairly easy to do
also any problems to do with them are eliminated,
while the carbs are off check the faces and flat as necessary
Although I have orings I made my own carb to manifold gaskets from thick card.
A set of new plugs never go a miss when problem solving
If you have not got a compression tester, you'll have to use your leg

when cold first press on the kickstart, slowly increasing weight
until it turns over "sssthuthumpclkclkclk"

do that twice and both times it should feel the same,
and take the same amount of pressure.
Get used to how it feels know your bike

To find the side you will have to take one plug out,
repeat the same test when it is hot and it should feel similar,
maybe a little easier as the oil is thin
If you have a tight valve you will get a lot of sissing
and it will turn easy with hardly any compression, depending on how tight.
If you know your valves are not tight, it could point to valve seats in need of a grind.

jrn · 09-10-2009, 09:39 AM

Well last night I made new O-rings and gaskets at work. The gaskets are 1/16" or .0625. and the O-ring was metric so it was a little thicker than a standard 1/16" O-ring measuring .070. I borrowed a compression and leak down tester and I will recheck my valves as well. I'll let you know how she goes, Thankfs for the help.

jrn · 09-10-2009, 11:41 AM

Rocker clearance stayed the same so that's good. Haven't even tried it hot yet, because cold compression test yielded bad news. 75lbs. on left and 88lbs. on the right. I'll try this homemade leak down tester and see if it's hopefully just rings. I hope I don't need a total head reubuild, a little short on $$. For those that are curious stay tuned!

Ok Hot it's of course worse, basically 45 lbs. L-R like every 4th kick it jumps to 65lbs. Top end rebuild here we come!

jimmy bush · 09-10-2009, 09:04 PM

Are you holding the throttle wide open and kicking until the pressure stops building when you do your compression test?

jrn · 09-11-2009, 01:54 AM

No I didn't test it that way, but I'm going to a Brit mechanic tomorrow for a liquid leak down test. Thanks